id stringlengths 12 12 | format stringclasses 2 values | title_ko stringlengths 0 811 ⌀ | title_en stringlengths 0 1.26k ⌀ | journal dict | authors listlengths 0 15 | abstract_ko stringlengths 0 4k ⌀ | abstract_en stringclasses 100 values | keywords stringclasses 157 values | citation_count stringclasses 5 values | doi stringlengths 0 127 ⌀ | url stringclasses 101 values | file_source stringlengths 23 23 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
ART001721356 | oai_dc | Geo-microbial and geochemical evidences in the near surface soils of Jamnagar sub-basin, Saurashtra, Gujarat, India: implications to hydrocarbon resource potential | Geo-microbial and geochemical evidences in the near surface soils of Jamnagar sub-basin, Saurashtra, Gujarat, India: implications to hydrocarbon resource potential | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Mohammed A. Rasheed(National Geophysical Research Institute); M. Lakshmi(National Geophysical Research Institute); M.S. Kalpana(National Geophysical Research Institute); P.L.S. Rao(National Geophysical Research Institute); D.J. Patil(National Geophysical Research Institute); V. Sudarshan(Osmania University); A.M. ... | The Jamnagar sub-basin of Saurashtra, Gujarat is considered geologically prospective for hydrocarbons by Directorate General of Hydrocarbons (DGH), India. However the major part of the Jamnagar sub-basin is covered by Deccan Traps, hindering the exploration of Mesozoic hydrocarbon targets. In India, significant hydrocarbon finding in the stratigraphic sequence has not been established, as the major part of the Mesozoic sediments is underlying the Deccan Traps. Detection and mapping of the Mesozoic sediments below the Deccan Trap has been a long-standing complex geophysical problem facing the oil industry. The vast sheet of volcanic cover, which overlies the Mesozoic sediments acts as a geophysical shield and inhibit the effective use of conventional seismic techniques. Surface geochemical techniques based on hydrocarbon microseepage from subsurface accumulations, have potential to evaluate the prospects for petroleum exploration. In view of this, surface geochemical survey for adsorbed soil gas and microbial analysis was conducted in Jamnagar sub-basin, total 150 near surface soil samples were collected for the evaluation of hydrocarbon resource potential of the Basin. Microbial analysis revealed high bacteria counts for methane (1.32×106 cfu/gm), ethane (8.50× 105 cfu/gm), propane (6.86×105 cfu/gm) and butane oxidizing bacteria (5.70×105 cfu/gm) in soil samples of Jamnagar sub-basin. The bacterial concentration distribution maps show three distinct anomalies in the study area, indicating hydrocarbon microseepage at these places. The geochemical investigations in soil samples showed the presence of high adsorbed hydrocarbon gases concentration of methane (C1) 1 to 518 ppb and Ethane plus hydrocarbons (C2+) 1 to 977 ppb respectively. Further, carrying out integrated geo-microbial and geo-chemical studies with adsorbed soil gas showed the anomalous hydrocarbon zones nearby Khandera, Haripur, and Laloi areas which could probably aid to assess the true potential of the Basin. On the basis of microbial prospecting and adsorbed soil gas studies Jamnagar sub-basin study area appears to be a warm zone for hydrocarbon prospects and needs detailed investigation with other geo-scientific methods. Integrated geophysical studies have shown that Jamnagar sub-basin of Saurashtra has significant sediment thickness below the Deccan Traps and can be considered for future hydrocarbon exploration. The corroboration of adsorbed light gaseous hydrocarbons and hydrocarbon oxidizing bacteria suggests its efficacy as one of the potential tool in surface geochemical exploration of hydrocarbons. | 지질학 | null | http://dx.doi.org/10.1007/s12303-012-0038-z | kci_detailed_000234.xml | ||
ART001721311 | oai_dc | Pseudofrenelopsis cf. parceramosa and its reproductive organs from the Lower Cretaceous Youngdong Group of Korea | Pseudofrenelopsis cf. parceramosa and its reproductive organs from the Lower Cretaceous Youngdong Group of Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Jong Heon Kim(Kongju National Univeristy); Ji Hye Seo(Kongju National University); Gi Soo Nam(Kongju National University)"
] | A large number of cheirolepidiaceous shoots and some associated male and female cones collected from the Lower Cretaceous Youngdong Group in the Youngdong area of Chungcheongbug-do, Korea, are described as Pseudofrenelopsis cf. parceramosa (Fontaine) Watson, its male cone of Classostrobus comptonensis Alvin et al. and female cone based on their external morphology respectively. The abundant presence of Pseudofrenelopsis shoots in the Youngdong Group indicates that it was a dominat group flourished during the Early Cretaceous in Korea | 지질학 | null | http://dx.doi.org/10.1007/s12303-012-0034-3 | kci_detailed_000234.xml | ||
ART001721371 | oai_dc | Microbial and chemical contamination of groundwater around livestock mortality burial sites in Korea – a review | Microbial and chemical contamination of groundwater around livestock mortality burial sites in Korea – a review | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"김현수(전북대학교); 김강주(군산대학교)"
] | This review defines and discusses type and fate of microbial contaminants expected to be found in the groundwater around livestock mortality burial pits. Reported results from simulated and actual mortality burial pits indicate that decomposition process of animal carcass requires at least 2 years for completion, generating the leachate with very high concentrations of chemical pollutants. These chemical constituents are likely to provide substrate for bacterial growth and affect microbial population dynamics in the subsurface. Anticipated microbial pollutants are classified into 3 categories. (1) enteric microorganisms including disease causing viruses, (2) bacteria participating in carcass decomposition, such as proteolytic and lipolytic bacteria, and (3) endogenous soil microorganisms. Experimental and field data indicate that pathogenic enteric viruses and bacteria may be able to survive in the animal body and natural environments for extended periods of time when ambient conditions are suitable for their survival. Proteolytic bacteria may affect pathogenicity of avian influenza viruses by controlling their cellular attachment and infiltration. Pathogenic soil bacteria can experience shift in population dynamics, with the introduction of leachate chemicals, from attached bacterial community with limited size to exponentially growing suspended biomass accustomed to the conditions in the groundwater. The possibility of extended survival of various sources of microbial contamination indicates the need to set up a method to properly monitor groundwater contamination to identify the presence of microbial contaminants and their interaction with chemical constituents. | 지질학 | null | http://dx.doi.org/10.1007/s12303-012-0036-1 | kci_detailed_000234.xml | ||
ART001721109 | oai_dc | Sequence-stratigraphic comparison of the upper Cambrian Series 3 to Furongian succession between the Shandong region, China and the Taebaek area, Korea: high variability of bounding surfaces in an epeiric platform | Sequence-stratigraphic comparison of the upper Cambrian Series 3 to Furongian succession between the Shandong region, China and the Taebaek area, Korea: high variability of bounding surfaces in an epeiric platform | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Jitao Chen(Seoul National University); S.K. Chough(Seoul National University); 이정현(서울대학교); Zuozhen Han(Shandong University of Science and Technology)"
] | This study focuses on the stratigraphic sequences and the bounding surfaces in the upper Cambrian Series 3 to Furongian Gushan and Chaomidian formations in the Shandong region, China. The bounding surfaces are compared with those of the coeval succession in the Taebaek area, Korea. According to the vertical arrangement of the facies associations and the identification of the bounding surfaces, three stratigraphic sequences are recognized, representing dynamic changes in accommodation versus sedimentation. The bounding surfaces can be traced in the Shandong region for about 6,000 km2 in area, but cannot be correlated with those of the Taebaek area (eastern margin of the platform, about 1,000 km apart). Surface 1 is characterized by an abrupt facies change from carbonate to shale, representing a distinct drowning surface. The drowning surface is also diagnosed in the Taebaek area but highly diachronous. Surface 2 is a cryptic subaerial unconformity, reflected by an erosion surface, missing of a trilobite biozone (Prochuangia Zone), and an abrupt increase in carbon isotope value. It is not identified in the Taebaek area where the Prochuangia Zone is present. Surface 3 is a marine flooding surface, indicated by a subtle transition from flat-bedded microbialite to domal microbialite (or grainstone). It may be correlated with that in the Taebaek area, which is, however, represented by an abrupt facies change from sandstone to limestone-shale alternation. The high variability of the sequence-bounding surfaces is indicative of variable regional factors such as topographic relief, carbonate production, siliciclastic input, and hydrodynamic conditions. It suggests that the sequence-bounding surfaces are invalid for a basin-scale correlation, especially in an epeiric carbonate platform | 지질학 | null | http://dx.doi.org/10.1007/s12303-012-0040-5 | kci_detailed_000234.xml | ||
ART001721362 | oai_dc | Groundwater response analysis to multiple earthquakes on Jeju volcanic island | Groundwater response analysis to multiple earthquakes on Jeju volcanic island | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Soo-Hyoung Lee(Korea Institute of Geoscience and Mineral Resources); 함세영(부산대학교); 하규철(한국지질자원연구원); 고경석(한국지질자원연구원); Jae-Yeol Cheong(Korea Radioactive Waste Management Corporation)"
] | Earthquakes have been known to induce a groundwater response. This study statistically analyzed the relationship between the changes in groundwater level (oscillation) and seismic waves, as well as the relationship between the changes in groundwater level and earthquakes of various magnitudes and epicenters more than 1,000 km distance from Jeju Island. The analysis showed that the groundwater level in Jeju Island is changed mostly by earthquakes larger than M = 7.0 within a 3,000 km from the epicenter. A positive relationship appeared between the earthquake magnitude and groundwater level change. A similar positive trend was observed between the maximum groundwater level and the seismic amplitude of the earthquakes. Geologically and spatially, the northern area of the island showed the highest response to earthquakes, the southern area showed an intermediate response, and the western and eastern areas showed the lowest response. The highest groundwater response in the northern area might be linked to its permeable structures and geological layers. | 지질학 | null | http://dx.doi.org/10.1007/s12303-012-0033-4 | kci_detailed_000234.xml | ||
ART001721302 | oai_dc | Middle Furongian (late Cambrian) polymerid trilobites from the upper part of the Sesong Formation, Taebaeksan Basin, Korea | Middle Furongian (late Cambrian) polymerid trilobites from the upper part of the Sesong Formation, Taebaeksan Basin, Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"박태윤(서울대학교); Jang Won Sohn(서울대학교); 최덕근(서울대학교)"
] | The upper part of the Sesong Formation of the Taebaek Group, Taebaeksan Basin, Korea, is known to contain the Kaolishania Zone which can be equated to the Kaolishania Zone of North China. Silicified trilobite sclerites were recovered from six horizons of the upper part of the Sesong Formation at the Sagundari section, which include a total of thirteen polymerid species: i.e., Shirakiella elongata Kobayashi, 1935, Shirakiella sp. 1, Taishania? sp. 1, Acanthometopus sp. 1, Pagodia sp. cf. P. spina Qian, 1994, Kaolishania granulosa Kobayashi, 1933, Gumunsoia triangularis gen. et sp. nov., Gumunsoia sp. 1, kaolishaniid genus and species indeterminate 1, Elaphraella? taebaeksanensis Park and Choi, 2012, Elaphraella microforma Lu and Qian, 1983, Elaphraella nodus (Qian, 1994), and Lingyuanaspis sp. The occurrence of Kaolishania suggests that the studied interval may be part of the Kaolishania Zone. However, Kaolishania occurs only from the lowermost horizon, and the full stratigraphic range of Kaolishania is unknown at present. Accordingly, the studied interval is provisionally called the Kaolishania fauna. The uppermost interval of this Kaolishania fauna produces Acanthometopus sp. 1, and thus can be correlated with the Acanthometopus Zone in Northeast China, which is underlain by the Kaolishania Zone | 지질학 | null | http://dx.doi.org/10.1007/s12303-012-0037-0 | kci_detailed_000234.xml | ||
ART001721340 | oai_dc | Typhoon-generated microseisms observed from the short-period KSRS array | Typhoon-generated microseisms observed from the short-period KSRS array | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"이우동(전북대학교); 조봉곤(전북대학교); Fred Schwab(University of California Los Angeles); Sat-Byul Jung(Chonbuk National University)"
] | The seismic-noise data recorded on 19 vertical-component short-period seismometers of the KSRS seismic array are analyzed (1) to determine whether typhoons in the Pacific Ocean can be tracked accurately, and (2) to explore the seismic phases comprising the noise field recorded at the array. For our tests, two super typhoons, Sinlaku and Rammasun of 2008, were selected on the basis of their strength and wide azimuthal coverage from the seismic array. To track the source of DF microseisms, f-k analysis was applied to the KSRS data to estimate the back azimuth of the 0.2–0.7 Hz noise field (DF microseisms). These computed back azimuths show good agreement with the known values to the centers of the NW Pacific typhoons. This clearly indicates that these typhoons were the main source of microseisms during their passing. The seismic phases in our DF microseism band are investigated with the phase velocities from our f-k analysis. The estimated horizontal phase velocities range from 3.2 to 3.8 km/s, with an average of about 3.5 km/s. This indicates that the major phases of the observed DF microseisms are surface waves consisting of mostly P-SV Mode 1 and Mode 2—in amplitude ratio A1/A2=1/3—and possibly some Mode 3. | 지질학 | null | http://dx.doi.org/10.1007/s12303-012-0039-y | kci_detailed_000234.xml | ||
ART001721333 | oai_dc | A study on using acoustic emission in rock slope with difficult ground – focused on rainfall | A study on using acoustic emission in rock slope with difficult ground – focused on rainfall | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Yo-Seph Byun(Hanyang University); Myung Sagong(Korea Railroad Research Institute); Suk-Chun Kim(U-Kyung Engineering & Construction); Byung Sik Chun(Hanyang University); Seong-Yong Park(Hanwha Research Institute of Technology); Hyuk-Sang Jung(Korea Railroad Research Institute)"
] | This study attempted to predict slope failures by applying AE techniques to a rock slope with a history of collapse. Damage levels were assessed on the basis of the AE characteristics estimated by conducting laboratory tests on simulated slope failures. The test results showed that the specimen showed a very high degree of failure at the initial stage of loading, which was analyzed using the AE characteristics to assess the damage levels. The variation in the measured number of AE hits and AE events in field tests may indicate minute variations in the slope. The measured values appeared to be insignificant as they were less than the minimum criterion for damage. An analysis of rainfall, which is an important factor in slope behavior, showed that as rainfall increased, the number of AE hits and AE events also increased. In particular, when the cumulative rainfall was constant, the cumulative number of AE hits and AE events appeared to converge, indicating that the cumulative rainfall and the number of AE hits are closely connected. When applying AE techniques to a slope that has a high probability of failure, the failure prediction of the specific location and the early prediction of failure behavior on rock slopes became possible. | 지질학 | null | http://dx.doi.org/10.1007/s12303-012-0035-2 | kci_detailed_000234.xml | ||
ART001721315 | oai_dc | Micro-characteristics of sustained, fine-grained lacustrine turbidites in the Cretaceous Hwangsan Tuff, SW Korea | Micro-characteristics of sustained, fine-grained lacustrine turbidites in the Cretaceous Hwangsan Tuff, SW Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"장태수(한국지질자원연구원); 전승수(전남대학교)"
] | A distinction between the classic Bouma turbidite and a hyperpycnite is needed because hyperpycnal flows provide a direct link between the terrestrial source and the depositional sink. These deposits are a potential record of river floods and hence contain tectonic and climatic information. Unlike the sandy turbidite or hyperpycnite, the muddy counterpart is generally poorly documented. Based on detailed sedimentological analysis of a deltaic mudstone unit within the Cretaceous Hwangsan Tuff, SW Korea, this paper addresses the characteristics and depositional processes of the lacustrine muddy turbidite or hyperpycnite. The Hwangsan Tuff is composed of reworked volcaniclastics up to 300 m thick, deposited in a lake margin, on a delta front to the basin plain. The thin-bedded mudstones constitute a diverse type of turbidites. Most mudstone beds generally show normal grading and are wavy in form, but internally demonstrate the existence of a depositional break such as an erosional surface and the repetition of rippled units. Thin-bedded mudstone with a pronounced normal grading is interpreted to have been deposited by small, dilute turbidity currents. However, a composite bed of lower massive siltstone overlain by a structureless claystone suggests deposition from slow-moving, high-density flows with high clay content. The hyperpycnal flow deposits in muds are characterized by a thickness change in the horizontal laminae, internal erosion scour, and the recurrence of rippled units, all of which are features indicating deposition from flow fluctuations in long-lived hyperpycnal flows. Abundant plant debris and a lack of bioturbation also support this hypothesis. The hyperpycnal flows form the mouth bars to delta front bodies of the lake margin | 지질학 | null | http://dx.doi.org/10.1007/s12303-012-0042-3 | kci_detailed_000234.xml | ||
ART001721327 | oai_dc | The A-type Pirrit Hills Granite, West Antarctica: an example of magmatism associated with the Mesozoic break-up of the Gondwana supercontinent | The A-type Pirrit Hills Granite, West Antarctica: an example of magmatism associated with the Mesozoic break-up of the Gondwana supercontinent | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Hyo Min Lee(Korea Institute of Geoscience and Mineral Resources); 이종익(한국해양과학기술원 부설 극지연구소); Mi Jung Lee(ea Polar Research Institute); Jeongmin Kim(Korea Basic Science Institute); Seok Won Choi(Kongju National University)"
] | The Mesozoic geology of West Antarctica is largely related with the break-up of the Gondwana supercontinent and offers a good example for understanding magmatism associated with the continental break-up process. West Antarctica can be divided into five crustal blocks with relatively thin crust. The blocks are separated by deep rift zones and have moved during the Mesozoic break-up of Gondwana. The Pirrit Hills granite occurs as an isolated pluton in the Ellsworth-Whitmore Mountains block, which is the center of five blocks in the present configuration. The granite consists of quartz, perthitic alkali feldspar, and plagioclase with minor amounts of interstitial biotite and muscovite. The granite is a highly homogeneous, strongly fractionated, and mildly peraluminous granite and belongs to A-type granites with A2-type characteristics, suggesting its generation in an anorogenic environment. The strong enrichment of HREE and significant negative Eu anomalies suggest that the granitic magma was produced by a small degree of partial melting of a garnet granulitic source in the unusually hot lower crust. A weighted mean 206Pb/238U age of zircons is 164.5 ± 2.3 Ma (MSWD = 1.3), which is 8 to 9 Mys younger than a former Rb-Sr whole rock age (173 ± 3 Ma), and corresponds to the first rifting stage of the break-up of Gondwana (at 165 Ma). We suggest this age to be the emplacement age of the Pirrit Hills granite. The A-type Pirrit Hills granite was emplaced in the Middle Jurassic accompanying crustal thinning due to the break-up of Gondwana | 지질학 | null | http://dx.doi.org/10.1007/s12303-012-0041-4 | kci_detailed_000234.xml | ||
ART001588913 | oai_dc | Impact of brownmillerite hydration on Cr(VI) sequestration in chromite ore processing residue | Impact of brownmillerite hydration on Cr(VI) sequestration in chromite ore processing residue | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"문덕현(조선대학교); Mahmoud Wazne(Stevens Institute of Technology)"
] | Experimental and modeling studies were conducted to delineate the reaction progress of chromite ore processing residue (COPR) upon hydration and the roles of brownmillerite and calcium aluminum chromium oxide hydrates (CAC) in the scavenging of hexavalent chromium. A kinetic study was conducted by preparing slurry samples with both synthetic brownmillerite and actual COPR samples at ambient temperatures. The hydration reaction of brownmillerite using synthetic brownmillerite was very fast (within 1 hour) and was completed within 2 days. However, the hydration of brownmillerite embedded in COPR to its hydration byproducts was not clearly observed after 7 days of aging. Newly formed Ca_4Al_2O_6(CrO_4)•14H_2O (CAC-14) was observed after 1 hour of aging in both samples. However, the rate of formation of CAC-14 with synthetic brownmillerite was much faster than the COPR embedded brownmillerite. The reaction progress of synthetic brownmillerite and COPR upon chromate influx was simulated by a reaction path modeling program. The phase transformation of both samples can be predicted by the constructed model. Moreover, the formation of CACs upon chromate addition was predicted by the model, suggesting an effective sink for Cr(VI) | 지질학 | null | kci_detailed_000234.xml | |||
ART001588904 | oai_dc | Hydrate growth in granular materials: implication to hydrate bearing sediments | Hydrate growth in granular materials: implication to hydrate bearing sediments | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"윤태섭(연세대학교); J. Carlos Santamarina(Georgia Institute of Technology)"
] | It is often assumed that the properties of hydrate-bearing sediments are affected by hydrate growth habits in pores. We test this hypothesis by stochastically simulating hydrate growth in pore space of a simple cubic packing of mono-sized spherical sediment grains, and assume three extreme nucleation preferences in the absence of heat or mass transport limitations, and without interfacial surface tension: (1) Homogeneous nucleation produces isolated nuclei and a highly porous hydrate mass; (2) Heterogeneous nucleation results in combined surface coating and frame-building hydrate structures; and (3) Preferential heterogeneous nucleation on pre-existing hydrate surfaces leads to hydrate growth into the pore space. Spatial distribution of hydrate is analyzed to investigate the surface coating density, grain connectivity and mass density of hydrate cluster. Results show that surface coating density is predominant for heterogeneous nucleation and grain connectivity by hydrates is lower than the hydrate volume fraction in all cases. Therefore, a slow increase in stiffness is anticipated at low hydrate volume fraction. The highly porous hydrate structure formed by homogeneous nucleation and dense hydrate cluster are discussed with the relevance to the geomechanical and physical properties of hydrate-bearing sediments | 지질학 | null | kci_detailed_000234.xml | |||
ART001588901 | oai_dc | Holocene vegetation dynamics and its climatic implications inferred from pollen record in Boseong area, South Korea | Holocene vegetation dynamics and its climatic implications inferred from pollen record in Boseong area, South Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"정철환(순천대학교)"
] | To investigate the Holocene vegetation and climate changes, pollen analysis performed on swamp deposits of the Boseong area, South Korea. From ca. 11,800 to 10,500 cal. yr BP, a cool temperate deciduous broadleaved forest dominated by Alnus and Quercus (Lepidobalanus) occupied the study area, indicating climatic warming during the Preboreal (earliest Holocene). A remarkable decrease in riparian Alnus and an increase in xerophytic Artemisia from ca. 10,500 to 8,400 cal. yr BP suggest open woodland with herbaceous understory reflecting a cool and dry condition. The expansion of deciduous broadleaved forest combined with rise in evergreen broadleaved taxa and the retreat of grassland between ca. 8,400 and 3,700 cal. yr BP indicate a vegetation shift from open woodland with herbaceous understory to warm temperate evergreen and deciduous broadleaved forests, resulted from climate amelioration during the Holocene climatic optimum. A warm and humid condition during this period is also evidenced by high values of pollen concentration. Vegetation change controlled by human impact occurred from ca. 3,700 to 2,900 cal. yr BP, as indicated by a rise in Pinus and Polypodiaceae and by high sedimentation rate. Along with the late Holocene climatic cooling, human impact brought about the development of Pinus dominated open woodland with a fern (Polypodiaceae) understory in the Boseong area | 지질학 | null | kci_detailed_000234.xml | |||
ART001588892 | oai_dc | Preliminary study on dinosaur rib microstructure by applying correlative microscopy techniques | Preliminary study on dinosaur rib microstructure by applying correlative microscopy techniques | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Jung-Kyun Kim(전남대학교); 허민(전남대학교); Seon-Gyu Lee(한국기초과학지원연구원); 김윤중(한국기초과학지원연구원)"
] | A dorsal rib portion from the post-cranial skeleton of a small ornithischian dinosaur discovered from the fossiliferous locality in Boseong was analyzed through Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Electron Probe Microanalyser (EPMA), X-ray Diffraction (XRD), and Transmission Electron Microscopy (TEM) to determine the detailed microstructure and components of the fossilized dinosaur bone. The rib bone portion was specifically chosen as an initial research sample to establish efficient experimental methodology in order to apply to future dinosaur osteohistological study. Since the fossilized bone was highly compressed by the surrounding matrix, distinct features of bone tissues were not clearly visible in OM cross sections. Instead, we observed two other features: (1) numerous patches of calcite crystals in various orientations filling the void region; (2) apatite crystals of 10~200 nm size constituting the bone matrix region, which is revealed by XRD, EPMA, SEM, and TEM. The data we have obtained so far is preliminary to directly elucidate the specific microstructural properties of fossilized bone such as bone formation and growth patterns, but we have provided possibility of revealing the characteristic features of dinosaur bone microstructure in nano-scale and established efficient specimen preparation methods for correlative Optical Microscopy (OM)-Electron Microscopy (EM) study | 지질학 | null | kci_detailed_000234.xml | |||
ART001588924 | oai_dc | A capillary number for physical displacement of TCE-DNAPL trapped in a rough-walled fracture | A capillary number for physical displacement of TCE-DNAPL trapped in a rough-walled fracture | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Hang-Bok Lee(Korea Atomic Energy Research Institute); 여인욱(전남대학교); 지성훈(한국원자력연구원); 이강근(서울대학교)"
] | A heterogeneous nature of rough-walled rock fractures complicates a recovery of DNAPL trapped in fractured rock aquifers, which forms a persistent plume within the fractured rocks and present a long-term source of contamination. Experimental studies were conducted to suggest a criterion for the physical displacement of DNAPL from rough-walled fractures in the context of capillary number (N_(ca)), a dimensionless number representing the ratio of the viscous to capillary forces. A series of experiments using water, surfactant solution and dense fluid were conducted in the range of capillary number from 2.29 × 10^(–4) to 3.41 × 10^(–2). The experimental results suggested that a higher capillary number than 1 × 10^(–2) be required for a near complete DNAPL removal (more than 95% of initial saturation) from rough-walled fractures. For capillary number on the order of 10^(–3), DNAPL can be mobilized or recovered to some degree. For the capillary number below 1 × 10^(–3), any kind of remedial fluids would have no effect on physical displacement. It is suggested that remedial fluid utilizing physical displacement be formulated to comply with N_(ca) > 1 × 10^(–2) to maximize a complete physical removal and the fluid utilizing chemical solubilization or reaction do with N_(ca) < 1 × 10^(–3) to minimize unwanted migration | 지질학 | null | kci_detailed_000234.xml | |||
ART001588930 | oai_dc | In-situ biosurfactant flushing, coupled with a highly pressurized air injection, to remediate the bunker oil contaminated site | In-situ biosurfactant flushing, coupled with a highly pressurized air injection, to remediate the bunker oil contaminated site | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"이민희(부경대학교); 김종성(부경대학교); 김인수(부경대학교)"
] | A pilot scale test for in-situ biosurfactant flushing coupled with a highly pressurized air injection (HPAI) was performed to remediate a bunker oil contaminated site. The contaminated area was located in Ulsan, Korea, which had been used for a roofing tile manufacturing facility for 25 years. This site was mainly contaminated by the leakage of bunker A- and C-oil from the old underground storage tank (the average TPH concentration of soil was 1,820 mg/kg). A pilot scale test site (17 m × 12 m × 4 m) was selected in the contaminated area and twelve injection wells and two extraction wells were established at the site. Two percent of biosurfactant solution was flushed into each injection well at 2 L/min, followed by HPAI (20 kgf/cm^2) to accelerate the mobility of flushed solution in pore spaces and thus to increase the removal efficiency of in-situ flushing. The process of biosurfactant flushing with HPAI was repeated until about 1.9 pore volumes of biosurfactant solution (350 tons) were flushed at the test site. The effluent solution was gathered and treated by a post treatment process that included a chemical reaction tank. A total of 2.2 ton of TPH (82% of the initial TPH) was removed from the site within 1.9 pore volumes of biosurfactant solution flushing resulting in the average TPH concentration of the residual soil being below 500 mg/kg, suggesting that the in-situ biosurfactant flushing coupled with HPAI, is very useful in remediating bunker oil contaminated sites | 지질학 | null | kci_detailed_000234.xml | |||
ART001588896 | oai_dc | The effects of depositional processes on benthic foraminiferal taphonomy in the Southeastern Yellow Sea of Korea | The effects of depositional processes on benthic foraminiferal taphonomy in the Southeastern Yellow Sea of Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"정다운(전남대학교); 최진용(군산대학교); 이연규(전남대학교)"
] | To understand the role of depositional processes on the distribution of benthic foraminifera, grain size analysis, paleontological statistics and textural analysis were conducted on three piston cores (Core Nos. 3, 7, 9) from the southeastern Yellow Sea of Korea. Two foraminiferal assemblages were defined by cluster analysis. The Cibicides lobatulus-Ammonia ketienziensis assemblage has low P.F/B.F, species diversity and evenness and high number of benthic foram. individuals/20 ml, and is interpreted as representing relict benthic foraminiferal assemblage comprising the upper layer of Core No. 7 and No. 9. The deposit of well sorted alternation layers of muddy sand and sandy mud in Core No. 9. is interpreted as being influenced by hydraulic sorting processes of higher wave and current especially during storm periods. The preservation of 13 Pseudorotalia gaimardii extracted from Core No. 7 confirmed that bed load transport was responsible for its heavily abraded and broken thick-walled tests. The Pseudoparrella naraensis assemblage is a recent benthic foraminiferal assemblage found in the modern homogeneous fine-grained mud facies corresponding to the uppermost part of HMB. It seemed that the apparent sorting phenomena and bed load transport of the benthic foraminifera are the result of turbidity currents which promulgated by rapid tidal currents formed during the last postglacial period in the southeastern Yellow Sea of Korea | 지질학 | null | kci_detailed_000234.xml | |||
ART001588942 | oai_dc | Waste disposal on karstic terrain: a case study from the ancient marble quarries in Iznik (Nicaea), Turkey | Waste disposal on karstic terrain: a case study from the ancient marble quarries in Iznik (Nicaea), Turkey | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Celalettin Simsek(Dokuz Eylul University); Ali Bahadir Yavuz(Dokuz Eylul University); Hakan Elci(Dokuz Eylul University); Alper Elci(Dokuz Eylul University); Orhan Gunduz(Dokuz Eylul University)"
] | This study is conducted in Iznik, a city situated in the Marmara region of Turkey. There are number of ancient marble pits in the area, some of which are used as sewage and solid waste dump sites. This study is aimed at investigating the hydrogeological and hydrogeochemical properties of Iznik plain with special emphasis on these waste sites. In terms of geological features, Derekoy metamorphics are basement rocks that consist of graphite schist, muscovite-quartz schist and marble lenses. Since Iznik marble was used as a natural construction material in the area since in the Roman era, 20 ancient marble quarries in different sizes existed in and around the study area. Wastewater from the city of Iznik and surrounding residential areas was disposed in three of these ancient marble quarries. In terms of hydrogeological features, the Iznik marble and alluvium units constitute the main aquifer system in the study area. Because of the highly fractured structure of the Iznik marble, the wastewater in the quarries was able to move rapidly within the rock. Analyses of groundwater samples revealed that the wastewater flowing in the marble unit discharges eventually into the alluvial unit and thereby affecting groundwater quality around the antique quarries. Based on chemical analyses results, the wastewater was Na-Cl water type and contained high concentrations of Na (3260 mg/l), K (903 mg/l) and Cl (10396 mg/l). Samples from wells down gradient of the wastewater source had comparatively higher Na, K and Cl concentrations | 지질학 | null | kci_detailed_000234.xml | |||
ART001588938 | oai_dc | Identification of aquifer system in the whole Red River Delta, Vietnam | Identification of aquifer system in the whole Red River Delta, Vietnam | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Duong Du Bui(Tokyo Metropolitan University); Akira Kawamura(Tokyo Metropolitan University); Thanh Ngoc Tong(Ministry of Natural Resources and Environment); Hideo Amaguchi(Tokyo Metropolitan University); Naoko Nakagawa(Tokyo Metropolitan University); Yoshihiko Iseri(Tokyo Metropolitan University)"
] | The Red River Delta is one of two biggest deltas in Vietnam. People living in the delta depend entirely on groundwater for their domestic water. However, the aquifer system in the whole Red River Delta remains poorly understood due to the lack of available data. Recently, we were nominated to construct a hydrogeological database. Using these valuable data contained in this database, this paper comprehensively analyzed the best number of 778 boreholes including well logs and their hydrogeological parameters obtained from pumping tests for the first time in order to identify the entire aquifer system and characterize hydrogeological conditions in the whole delta for potential groundwater resources. Great efforts have been made to establish and analyze hydrogeological maps, cross sections, and contour maps of main aquifers’ thickness and transmissivity. As for the results, we found that groundwater mainly exists in Quaternary unconsolidated sediments as porous water forming the topmost Holocene unconfined aquifer (HUA) and the shallow Pleistocene confined aquifer (PCA) sandwiching the Holocene-Pleistocene aquitard (HPA), while cleft and karst water exist in consolidated Neogene formations and Mesozoic rocks constituting the Neogene water bearing layer (NWL) and Mesozoic fractured zones (MFZ), respectively. PCA is almost entirely distributed over the delta. It serves as the highest groundwater potential and the most important aquifer for water supply. HUA is also widely distributed about 88% over the delta and has a high groundwater potential. NWL and MFZ, placed below PCA but exposed on the surface outside the delta, are minor sources for local domestic water supply only. These findings are indispensable for further groundwater analyses needed to ensure the sustainable groundwater development for the high-security water requirements in the delta, but have never been completed sufficiently before due to the unavailability of large-scale basic data sets | 지질학 | null | kci_detailed_000234.xml | |||
ART001588910 | oai_dc | Geochemical characteristics of calcareous and non-calcareous shales from the Meso-Neoproterozoic basins of the Bastar craton, Central Indian Shield: implications for provenance, tectonic setting, paleoweathering and paleoredox conditions | Geochemical characteristics of calcareous and non-calcareous shales from the Meso-Neoproterozoic basins of the Bastar craton, Central Indian Shield: implications for provenance, tectonic setting, paleoweathering and paleoredox conditions | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Hamidullah Wani(Amar Singh College); Mohammad Erfan Ali Mondal(Aligarh Muslim University)"
] | The Meso-Neoproterozoic shales of the Bastar craton, Central Indian Shield have been analyzed geochemically to study their geochemical characteristics and to evaluate paleoweathering, provenance, tectonic setting and paleoredox conditions. The shale samples have been classified into the calcareous and the non-calcareous shales on the basis of presence of calcite and CaO concentrations. In comparison to the calcareous shales, the non-calcareous shales have higher concentrations of most major elements and trace elements including rare earth elements (REEs). The Upper Continental Crust (UCC) normalized elemental ratios of the calcareous and the non-calcareous shales suggest evolved sources similar to the UCC (Upper Continental Crust). The Th/Co versus La/Sc and La-Th-Sc diagrams, chondrite normalized REE patterns and negative Eu/Eu* values of the calcareous and non-calcareous shale samples further reveal that the sediments have been derived from a felsic source and the source rocks have been identified to be the granites and the gneisses of the Bastar craton. The SiO_2 versus K_2O/Na_2O and the SiO_2/Al_2O_3 versus K_2O/Na_2O tectonic setting discrimination diagrams indicate sediments were deposited in a passive margin tectonic setting. The CIA (Chemical Index of Alteration), PIA (Plagioclase Index of Alteration), Th/U and K/Rb ratios and the K_2O-Fe_2O_3-Al_2O_3 relations of both the calcareous and the non-calcareous shales indicate that source area was affected by moderate to intense weathering history. The geochemical parameters like Ce/Ce* and Mn* suggest that the calcareous shales were deposited in suboxic environment compared to the non-calcareous shales | 지질학 | null | kci_detailed_000234.xml | |||
ART001588919 | oai_dc | Sensitivity analysis of marine controlled-source electromagnetic methods to a shallow gas-hydrate layer with 1D forward modeling | Sensitivity analysis of marine controlled-source electromagnetic methods to a shallow gas-hydrate layer with 1D forward modeling | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"이기하(부경대학교); 장한길로(부경대학교); 장한누리(부경대학교); 김희준(부경대학교)"
] | A computer program has been developed to evaluate electromagnetic (EM) responses for a one-dimensional (1D) model with multiple source and receiver dipoles that are finite in length. Using the 1D code, we conducted sensitivity analysis of marine controlled-source EM methods to a gas-hydrate layer in the shallow section. In this study we used a normalized amplitude and amplitude difference of EM fields simultaneously in determining the detection capability of the hydrate layer. The field amplitude must be normalized by the one for the corresponding background model without the hydrate layer. The normalized amplitude can be numerically large, but if the field amplitude is smaller than the threshold, it would be misleading and therefore is useless. From these numerical experiments, we found that there are plenty of useful offset ranges and frequencies where amplitude difference is large enough to detect the target layer. Furthermore, an effect of air waves is almost absent in amplitude difference | 지질학 | null | kci_detailed_000234.xml | |||
ART001561803 | oai_dc | Petrologic, chemical, and isotopic evaluation of pitchstones in the Samho area, southwestern Okcheon Belt, South Korea | Petrologic, chemical, and isotopic evaluation of pitchstones in the Samho area, southwestern Okcheon Belt, South Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"조규성(전북대학교); V. J. Rajesh(Indian Institute of Space Science and Technology); 강성승(조선대학교); 김정빈(순천대학교)"
] | The Samho area in the southwestern Okcheon Belt, Korean Peninsula, contains spatially related eruptions of lapilli tuff, rhyolite, and pitchstone, considered to be of Late Cretaceous age. The pitchstones, which are the youngest rocks in this volcanic suite, are chemically highly evolved, strongly metaluminous to weakly peraluminous, and calc-alkaline. They have moderately fractionated chondrite-normalized rare earth element (REE) patterns, with relative enrichment of light REEs and Eu/Eu* values of 0.53–0.57. A distinct negative Nb anomaly is observed on a primitive mantle-normalized trace element diagram. These chemical features correspond to an I-type granite derived from a continental/oceanic arc. The pitchstones have Zr contents of 45–92 ppm, and zircon thermometry yields temperatures of 650–743 ℃ (mean value, 722 ℃). The pitchstones have an initial ^(87)Sr/^(86)Sr isotopic ratio of 0.712, an initial ^(143)Nd/^(144)Nd ratio of 0.5120, and aNd_((t)) values of –10.6 to –12.0. The mean K-Ar whole-rock ages of the lapilli tuff, rhyolite, and pitchstone are 81.9 ± 2.4 Ma, 65.5 ± 1.9 Ma, and 12.7 ± 0.9 Ma, respectively. The depleted mantle model ages (TDM) range from 1.46 to 1.58 Ga. The ^(206)Pb/^(204)Pb, ^(207)Pb/^(204)Pb, and ^(208)Pb/^(204)Pb isotopic ratios are 18.477–18.569, 15.672–15.702, and 38.889–38.999, respectively. The Sr and Nd isotopic compositions of the pitchstones are relatively enriched compared with depleted MORB mantle (DMM), indicating the involvement of lower crustal components in their source. We conclude that the pitchstones in the Samho area formed in a continental arc setting by partial melting of a probable Mesoproterozoic parental source. The magma series, petrogenesis, and tectonic setting of Late Cretaceous magmatism in the Samho area can be correlated with those of the Haenam volcanic fields located east of the present study area | 지질학 | null | kci_detailed_000234.xml | |||
ART001561911 | oai_dc | Evidence for a relationship between hydrocarbon microseepage and trace metal anomalies: an implication for petroleum exploration | Evidence for a relationship between hydrocarbon microseepage and trace metal anomalies: an implication for petroleum exploration | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Todupunuri Madhavi(National Geophysical Research Institute); Munnuru S. Kalpana(National Geophysical Research Institute); Dattatray J. Patil(National Geophysical Research Institute); Anurodh M. Dayal(National Geophysical Research Institute)"
] | The paper reports the role of hydrocarbon microseepage in surface alterations of trace metal concentrations. In this study trace metal alterations were mapped that appear to be associated with hydrocarbon microseepages in the oil/gas fields of Mehsana block, North Cambay basin, India. The ranges of adsorbed soil gas concentrations of Methane, Ethane, Propane, i-Butane and n-Butane are found to vary from 1–402 ppb, 1–135 ppb, 1–70 ppb, 1–9 ppb, 1–18 ppb respectively, suggesting the presence of hydrocarbons and microseepage associated with the study area. The carbon isotopic signature of methane ranged from –29.5 to –43.0‰ (PDB) and ethane from –19.1 to –20.9‰ (PDB), indicating a thermogenic source of hydrocarbons. The absence of any significant correlation of Total Organic Carbon (TOC) and Total Inorganic Carbon (TIC) (r = 0.1 and 0.5 respectively) content with hydrocarbons in soil samples demonstrates the catagenetic origin of the desorbed gases. The Trace metal concentrations varied in the following manner: Ni: 49–155 ppm, V: 67–158 ppm, Cu: 29–82 ppm, Zn: 64–327 ppm, Ba: 241–554 ppm and Sr: 118–892 ppm. These high concentrations of trace metals which are more than their respective average concentrations generally found in soils are indicative of hydrocarbon induced alterations in the area. The low Eh values observed in anomalous hydrocarbon bearing soil samples compared to non anomalous samples in the area, could be attributed to the reducing conditions created by the hydrocarbon seepage from subsurface and might have influenced the trace metal solubilities which is reflected in their increased concentrations. Trace metal anomalies are seen haloed to adsorbed soil gas anomalies (∑C_(2+)) indicating that the major generative depressions of oil and /or gas fields of Sobhasan / Linch in the study area promoted vertical migration of hydrocarbon microbubbles which in turn facilitated trace metal deposition in the surface soils. By using integrated method approach, the weak signal of oil and gas reservoirs could be amplified in the frontier areas and the uncertainity of the vertical correlation of surface anomalies could be reduced | 지질학 | null | kci_detailed_000234.xml | |||
ART001561933 | oai_dc | Optimal management design of a pump and treat system at the industrial complex in Wonju, Korea | Optimal management design of a pump and treat system at the industrial complex in Wonju, Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"박유철(강원대학교); 정지민(Kangwon National University); 엄성일(Kangwon National University); Ui-Pyoung Jeong(Kangwon National University)"
] | The optimization of the management design for the remediation of contaminated groundwater, using a pump and treat system, was performed for an industrial complex site in Wonju, Korea. The groundwater in the study area was contaminated with trichloroethylene (TCE) and other solvents. The pump and treat system was selected as a remediation technique, with a genetic algorithm selected as the optimization technique. The groundwater flow and contaminant transport were simulated using MODFLOW, MT3D and RT3D. Three possible scenarios were considered to obtain a cost effective remediation strategy. The cost effectiveness was determined by the total cost, including the installation cost of pumping wells and the operational cost of the pump and treat system. Scenario 1 involved the removal of TCE from the entire contaminated area using pre-existing candidate pumping wells and additional candidate wells. The results with scenario 1 showed that additional candidate wells were required to reduce the total remediation cost. Scenario 2 involved the simultaneous removals of TCE and other solvents from the entire contaminated area. The total cost of scenario 2 was 180% that of scenario 1. Scenario 3 entailed containing the TCE within a compliance line, with another remediation technique applied to the rest of the contaminated area to reduce the total remediation cost. The total cost of scenario 3 was reduced to 37% that of scenario 1 under the same cleanup time constraint. If the cost of the other remediation technique does not exceed the difference between the total costs of the other two scenarios, the optimal management design of scenario 3 would be the most cost effective remediation strategy | 지질학 | null | kci_detailed_000234.xml | |||
ART001561848 | oai_dc | Mesozoic paleostress from healed microcracks and fluid inclusions in some granites of South Korea | Mesozoic paleostress from healed microcracks and fluid inclusions in some granites of South Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"장보안(강원대학교); 강성승(조선대학교)"
] | Mesozoic maximum horizontal stress (σ_(H max)) directions are determined from healed microcracks and the secondary fluid inclusions within healed microcracks in granites from the Inje, Jecheon, Wolaksan and Sokrisan areas. The strike of healed microcracks in granite from the Inje area shows a strong peak at N50˚W, while N10˚W and N80˚E are well developed as secondary and the tertiary peaks, respectively. N30˚W is the most dominant strike direction of healed microcracks in granites from the Jecheon area, while E-W is the second most dominant strike direction. Orientations of healed microcracks in granite from the Wolaksan area show a strong peak trend of N55˚W, while the secondary peak is at N5˚E. The most dominant strike direction of healed microcracks in granites from the Sokrisan area is N-S. The age for the formation of healed microcracks is determined from homogenization temperatures of fluid inclusion and the cooling history of granites. The age of healed microcrack formations in the Jecheon granite might be 207~149 Ma, 176~160 Ma in the Inje granite, 116~88 Ma in the Wolaksan granite and 92~84 Ma in the Sokrisan granite. In addition, the age of the NW-SE healed microcrack in the Wolaksan granite is 95 Ma, and that of the N-S healed microcracks in the Wolaksan and Sokrisan granites is 100~84 Ma and 92~84 Ma, respectively. This means that the rotation of principal stress axes occurred at 100~95 Ma. The σ_(H max) direction in the Korean peninsula was NW-SE in the Late Triassic to Early Cretaceous times, but changed to N-S in the Late Cretaceous. The directions and ages for the formation of healed microcracks in the study area are well correlated with Mesozoic tectonism in South Korea, that is, the Daebo orogeny in the Jurassic~Early Cretaceous with the σ_(H max) direction of NW-SE mainly having an effect on the Jecheon, the Inje and the Wolaksan granite, and the Middle~Late Cretaceous Bulguksa tectonic event with the σ_(H max) direction of N-S mainly having an effect on the Sokrisan granite. | 지질학 | null | kci_detailed_000234.xml | |||
ART001561783 | oai_dc | Deposition from pyroclastic surges partially blocked by a topographic obstacle: an example from the Ilchulbong tuff cone, Jeju Island, Korea | Deposition from pyroclastic surges partially blocked by a topographic obstacle: an example from the Ilchulbong tuff cone, Jeju Island, Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"전용문(제주특별자치도 세계자연유산관리본부); 권창우(한국지질자원연구원); 손영관(경상대학교)"
] | Ilchulbong (Jeju Island, Korea) is a UNESCO World Heritage site that has outstanding coastal exposures of a tuff cone formed by a phreatomagmatic eruption of basaltic magma in a shallow sea. Wet fallout and subsequent resedimentation processes were predominant means of emplacement of the tuff cone. The marginal deposits of the tuff cone show, however, peculiar deposit features which resulted from the interaction of wet pyroclastic surges and a topographic obstacle, a ~30 m-high dissected scoria cone. These features include steeply dipping, inversely graded strata, a breccia bed composed of thin-laminated fine tuff clasts, and isolated tuff clasts within some lapilli tuff beds. These features indicate that the depositional system (underflow or bedload layer) and the transport system (overlying suspension current) of the pyroclastic surges underwent different responses upon colliding with the topographic obstacle. The coarse-grained materials in the depositional system were mostly blocked by the obstacle, producing a scree-like wedge of deposits containing inversely graded grain-flow strata. In contrast, the transport system was not significantly affected by the obstacle, maintaining its momentum and original flow direction after passing over the dissected scoria cone. Some of the fine-grained load in the transport system was, however, plastered onto the cliff wall. The plastered tuffs were later detached and fell from the wall, resulting in an intraformational breccia bed and exotic tuff clasts within some lapilli tuff beds. The studied site, located within a scenic World Natural Heritage site, can be utilized as an important geosite for the education of the processes which occur during the collision of a pyroclastic density current with a topographic obstacle and the different fates of the depositional and transport systems of a pyroclastic density current. | 지질학 | null | kci_detailed_000234.xml | |||
ART001561826 | oai_dc | Sr-Nd-Pb isotopic compositions of submarine alkali basalts recovered from the South Korea Plateau, East Sea | Sr-Nd-Pb isotopic compositions of submarine alkali basalts recovered from the South Korea Plateau, East Sea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"이미정(극지연구소); 이종익(극지연구소); 권성택(연세대학교); 추미경(극지연구소); 정갑식(한국해양연구원); 조진형(한국해양연구원); 김성렬(한국해양연구원)"
] | We present geochemical and isotope results (Sr, Nd, Pb) on submarine basalts dredged from the southeastern margin of the South Korea Plateau. The present data are the first geochemical result obtained on submarine basaltic lavas recovered from the Korea Plateau, which is considered to be one of rifted remnants of continent in the East Sea (Sea of Japan) and partially segmented from the Korean Peninsula. The South Korea Plateau basalts (SKPB) show alkali affinities and are characterized by Ocean Island Basalts (OIB)-like trace element compositions relatively enriched in Ba, Nb and Pb. They display relatively flatter [(Ce/Yb)n = 4.49~5.46] and less fractionated HREE [(Dy/Yb)n = 1.11~1.29] patterns compared to average OIB, implying that the SKPB were derived from a relatively shallower mantle depth with a larger degree of partial melting. The Sr, Nd and Pb isotopic compositions of the SKPB display a range of values for ^(87)Sr/^(86)Sr (0.70378 to 0.70409), ^(143)Nd/^(144)Nd (0.512846 to 0.512860) and ^(206)Pb/^(204)Pb (17.88–18.44). They show a considerably high range of ^(207)Pb/^(204)Pb (15.48–15.62) and ^(208)Pb/^(204)Pb (37.86–38.46) values, indicating the involvement of a DUPAL-like MORB source. According to our two-stage magma mixing model, the isotopic compositions of SKPB can be explained by magma source mixing by the addition of an EMII-like mantle component (up to 2%) to the DUPAL-like MORB source embedded with endogenous EMI-like material (about 2%). | 지질학 | null | kci_detailed_000234.xml | |||
ART001561901 | oai_dc | Geochemistry of Çamardl Formation sediments, central Anatolia (Turkey): implication of source area weathering, provenance, and tectonic setting | Geochemistry of Çamardl Formation sediments, central Anatolia (Turkey): implication of source area weathering, provenance, and tectonic setting | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Seref Keskin(Nigde University)"
] | The upper Cretaceous-Eocene ‚amardl Formation is exposed along the northern edge of the Ulukl la Basin (central Anatolia) and consists of turbiditic sediments. The sediment geochemistry has been studied in order to understand the provenance, source area weathering, and tectonic setting of the basin. ‚amardl Formation sediments are characterized by low to moderate SiO_2 contents, variable abundances of major elements, and a relatively high proportion of ferromagnesian elements. Evidence from discrimination diagrams of sedimentary provenance, tectonic setting, major element geochemistry and Sc/Th, Cr/Th, Co/Th, Zr/Sc, La/Sc, La/Co, Cr/Sc, Y/Ni, and K/Rb values show that the ‚amardl Formation sediments were derived from mafic, felsic, and intermediate sources. The chemical index of alteration (CIA: 57.63–78.11) revealed moderately weathered source rocks. Then major and trace element concentrations indicated deposition in an active continental margin and continental island arc settings. | 지질학 | null | kci_detailed_000234.xml | |||
ART001561788 | oai_dc | K-Ar dating of illites for time constraint on tectonic burial metamorphism of the Jurassic Nampo Group (West Korea) | K-Ar dating of illites for time constraint on tectonic burial metamorphism of the Jurassic Nampo Group (West Korea) | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"에가와코우스케(서울대학교); 이용일(서울대학교)"
] | The timing of tectonic burial metamorphism of the early Mesozoic Nampo Group (western Korea) related to the Jurassic Daebo orogeny was first constrained by K-Ar dating of illite in sedimentary rocks. Two shale samples show a clear decreasing trend of both the amount of detrital component and K-Ar age of illites with decreasing grain size from >4 μm to 4–2 μm, and to <2 μm fractions. This observation most likely reflects a binary mixture of old detrital 2M1 and young authigenic 1M_d illites, usually seen in argillaceous sedimentary rocks. In this sense, the latest illitization attributable to the crustal loading can be estimated to be 157–140 Ma, the extrapolated illitic age inferred from a linear regression between the amount of detrital component and apparent K-Ar age of different size fractions. This result suggests that the maximum tectonic burial metamorphism of the Nampo Group has occurred in the last stage of the Daebo orogeny | 지질학 | null | kci_detailed_000234.xml | |||
ART001561893 | oai_dc | In-situ trace element analysis of clinopyroxene on thin section by using LA-ICP-MS | In-situ trace element analysis of clinopyroxene on thin section by using LA-ICP-MS | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"길영우(Korea Institute of Geoscience and Mineral Resources); Hyung-Seon Shin(Korea Basic Science Institute); Hae-Young Oh(Korea Basic Science Institute); 김정숙(Kangwon National University); 최민석(Korea Basic Science Institute); 신홍자(Korea Institute of Geoscience and Mineral Resources); 박찬수(Korea Basic Science Institute)"
... | Among the common minerals of the spinel peridotites, clinopyroxene is the main carrier of trace elements and serves as a tracer of geological mantle processes. The trace element composition of clinopyroxenes on a thin section 30 μm thick was measured using LA-ICP-MS. The repeatability of thin section analysis was better than 3% at the 2 sigma level. When using a 213 nm laser with a 55 μm beam size, optimal analytical conditions for the LA-ICP-MS were determined to be a 55% energy level (9 J/cm^2) and 10 Hz repetition rate, giving a penetration speed of clinopyroxene of 0.17 μm/pulse. Overall, the LA-ICP-MS technique can be used to determine the trace element composition of clinopyroxenes on thin sections with reasonable precision, accuracy, and limit of detection. | 지질학 | null | kci_detailed_000234.xml | |||
ART001647346 | oai_dc | Evaluation of spatio-temporal trends of groundwater quality in different land uses using Kendall test | Evaluation of spatio-temporal trends of groundwater quality in different land uses using Kendall test | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Dugin Kaown(Seoul National University, R.O. Korea); 현윤정(한국환경정책·평가연구원); 배광옥(서울대학교); 오창환(전북대학교); 이강근(서울대학교)"
] | The monitoring of temporal and spatial variations of groundwater quality is important for better managing groundwater resources. In a heavily cultivated agricultural site, Yupori, Chuncheon (Korea), groundwater quality has been monitored since 2002 because the groundwater in this area contains elevated levels of nitrate. Concentrations of NO3-N, SO42, and Cl were found to be high in vegetable fields and low in fruit orchards. For groundwater management purposes, a regional Kendall test was carried out to investigate the spatio-temporal trends of three major anion (NO3-N, SO42, and Cl) concentrations for various land use types: vegetable fields, fruit fields, and barns. The mean concentration of NO3-N in the vegetable fields exceeded the maximum contaminant level for drinking water (10 mg L1) and showed the highest increasing trend with time among the various land use types. The results showed a statistically significant increasing trend in the NO3-N and SO42 concentration in vegetable fields from 2002 to 2007. The estimated slope of the NO3-N and SO42 concentration in the vegetable fields was 2.1 mg L1 per year and 1.01 mg L1 per year over a period of 6 years. The concentration of Cl showed an increasing tendency in fruit fields and decreasing tendency in barns. In order to regulate groundwater quality in the study area, nitrate contamination in vegetable fields should be particularly controlled. Spatio-temporal trends for different land uses using regional Kendall test can be usefully applied to control groundwater quality in the study area. | 지질학 | null | kci_detailed_000234.xml | |||
ART001647328 | oai_dc | The origin of cold-water authigenic carbonates from deep-water, muddy sediments in the Ulleung Basin, East Sea of Korea | The origin of cold-water authigenic carbonates from deep-water, muddy sediments in the Ulleung Basin, East Sea of Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Odette Nehza(Korea Institute of Geoscience and Mineral Resources, R.O. Korea); 우경식(강원대학교); 천종화(Korea Institute of Geoscience and Mineral Resources, R.O. Korea); Jang-Jun Bahk(Korea Institute of Geoscience and Mineral Resources); Jin Kyung Kim(Korea Ocean Research and Development Institute, R.O. Korea); Sangmin Hyu... | Carbonate concretions associated with recently discovered gas hydrates from the East Sea (Sea of Japan), Korea, were investigated to delineate their origin based on textural, mineralogical and stable isotopic data. Authigenic carbonates were sampled from the 8 m-long piston core recovered from a water depth of 2072 m during a gas hydrate exploration cruise in June 2007. The carbonate concretions occur at three intervals from a depth of 220 to 280 cm from the top of core within hemipelagic muds above massive and vein-filling gas hydrate layers from depth of 329 to 655 cm. Semi-lithified carbonates occur as concretions with knobby, rounded and irregular morphologies. Textural observation of the concretions reveals porous surfaces with a spongy texture and distinctive internal layering. These concretions are mostly composed of aragonite with relatively minor contribution of calcite, with transition from calcite- to aragonite-dominating phase towards the periphery. Highly negative 13C values (13C = 43 to 27‰ PDB) suggest that methane was the main carbon source for their formation. Oxygen isotope values (18O = 1.1 to 3.1‰ PDB) are slightly enriched due to the relatively stable cold temperature of the East Sea bottom water (04 ûC). Distinctively separate and narrow ranges of stable isotope compositions from each concretion and the enrichment of carbon isotopes with depth indicate that the concretions at three intervals formed independently during different periods, but under similar anoxic diagenetic conditions by anaerobic oxidation of methane. In addition, distinctive geochemical clusters of each concretion with depleting oxygen isotope trend toward the periphery strongly suggest that the concretions in this study were formed separately by pore water interactions with adjacent surrounding pelagic muds. | 지질학 | null | kci_detailed_000234.xml | |||
ART001647357 | oai_dc | Book review: The Tectonics of China [Data, Maps and Evolution] | Book review: The Tectonics of China [Data, Maps and Evolution] | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"장기홍(경북대학교)"
] | 지질학 | null | kci_detailed_000234.xml | ||||
ART001647322 | oai_dc | Furongian conodonts from the Machari Formation in the Gokgeum section, Yeongwol, Korea | Furongian conodonts from the Machari Formation in the Gokgeum section, Yeongwol, Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Byung-Su Lee(Chonbuk National University)"
] | This is a conodont biostratigraphic study on the Machari Formation in the Gokgeum section, exposed nearby Mt. Orosan, Hutan-ri, west Yeongwol-gun, Korea. Three biostratigraphic intervals are recognized by euconodont taxa in the Furongian part of the Gokgeum section: i.e., Unnamed, Proconodontus muelleri, and Eoconodontus notchpeakensis zones in ascending order. The Unnamed zone herein is equivalent to the previous “Barren Interzone”, the Proconodontus muelleri Zone is also equivalent to the previous Proconodontus muelleri-Cambrooistodus cambricus Zone, and the Eoconodontus notchpeakensis Zone is a new, uppermost one. Therefore, there are four conodont zones of the Machari Formation known hitherto; i.e., late Middle Cambrian Westergaardodina matsushitai Zone and three Furongian zones including Unnamed zone, Proconodontus muelleri Zone and Eoconodontus notchpeakensis Zone in ascending order. These Machari conodont biozones are correlated with conodont biozonal frameworks in western USA, Canada, Argentina, North and South China, Australia and Hwajeol Formation in the Duwibong area, Korea. | 지질학 | null | kci_detailed_000234.xml | |||
ART001647360 | oai_dc | Variations of reflection and transmission coefficients at the boundaries of different media and types of contact between media | Variations of reflection and transmission coefficients at the boundaries of different media and types of contact between media | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"이정모(경북대학교); Margarita N. Luneva(Far East Branch of the Russian Academy of Sciences, Russia)"
] | Wave amplitudes and amplitude ratios between different wave types carry information about variations of medium properties with depth and time. The most information is contained in the reflection and transmission coefficients, which depend on the physical properties of contacting media and boundary conditions. In this paper, the range of variations in reflection and transmission coefficients of plane waves generated at boundaries with different properties is examined. Numerical simulations of coefficients were carried out for the models of rigid and non-rigid contact between isotropic and anisotropic media. At the rigid contact between isotropic media, amplitudes of generated waves and their ratios vary within relatively narrow limits while the physical parameters of the media may accept various reasonable values. In anisotropic media, coefficients depend not only on the slowness contrast, but also on the wave polarization directions, which may vary considerably in space. Amplitude ratios of generated waves may vary significantly with the incident angle, and the amplitudes of converted waves may dominate or be comparable with monotype waves. Introducing non-rigid contact between media considerably broadens the range of coefficient variations. In contrast to the rigid contact, the incident energy goes predominantly into reflected and converted waves. The amplitude of converted waves may be relatively large and exceed the amplitudes of monotype and incident waves. In general, reflection and transmission coefficients generated at non-rigid contact depend on the values of stiffness coefficients and their ratio. | 지질학 | null | kci_detailed_000234.xml | |||
ART001647311 | oai_dc | Influence of the M9.0 Tohoku Earthquake on groundwater in Korea | Influence of the M9.0 Tohoku Earthquake on groundwater in Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"이현아(연세대학교); 우남칠(연세대학교)"
] | The M9.0 earthquake occurred at 05:46:23 UTC on March 11, 2011 off the coast of Tohoku, Japan, causing devastating tsunami-driven disasters along coastal areas. The influence of the Tohoku earthquake was detected at 46 of 320 monitoring wells of the Korea National Groundwater Monitoring Network (NGMN) in terms of changes in water level, temperature, and electrical conductivity. Because the direction of water-level movement and its permanency was complicated, we classified water-level changes in wells into four types: Type I, wells in which the water level rose and did not recover during the observation period of three weeks (n = 7); Type II, wells in which the water level rose but then recovered (n = 4); Type III, wells in which the water level decreased without recovery (n = 23); Type IV, wells in which the water level declined but then recovered (n = 9). Type I and III wells were seen as evidence that the seismic waves from the earthquake had a significant impact and resulted in persistent changes in the groundwater system. Type II and IV wells showed changes in water levels of less than 20 cm to seismic waves transmitted through the aquifer system, indicating that these wells are earthquake-sensitive and may potentially be used for continuous earthquake monitoring. The combination of present seismic monitoring systems with groundwater monitoring at earthquake-sensitive wells could improve earthquake prediction and prevent earthquake-related disasters. | 지질학 | null | kci_detailed_000234.xml | |||
ART001647353 | oai_dc | Feasibility of the P- and S-beam methods for stability estimation of the Daegok dam in Korea | Feasibility of the P- and S-beam methods for stability estimation of the Daegok dam in Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"김형수(중원대학교); 김원기(서울대학교); 민동주(서울대학교); 하익수(Korea Water Resources Corporation, R.O. Korea); Jung-Yul Kim(Soam Consultant Co., Ltd., R.O. Korea); Yu-Sung Kim(Soam Consultant Co., Ltd., R.O. Korea)"
] | We investigate the feasibility of using the P- and S-beam seismic methods to evaluate the stability of dams, employing these methods to analyze the Daegok dam in Korea (a concrete faced rockfill dam; CFRD). In the beam method, adjacent shot gathers are stacked to generate super shot gathers, which can be similar to those obtained using a group of shots or groups of geophones. In the super shot gathers, surface waves and unwanted noises may be suppressed due to phase shifts that occur at adjacent shot gathers, whereas deep reflection events with slight phase differences may be enhanced. For this reason, deep reflection events can be better imaged than shallow ones. By applying the P- and S-beam methods to the Daegok dam, we were able to image the interior structures of the dam and determine physical properties such as velocities and the Poisson’s ratio. Compared with the velocities obtained from borehole P-S logging for other rockfill dams, the velocities and Poisson’s ratio obtained for the Daegok dam are reasonable. Given that a strong source generator cannot be used with dams because it might damage them, we feel that the P- and S-beam methods can be effective means of evaluating dam safety. | 지질학 | null | kci_detailed_000234.xml | |||
ART001647342 | oai_dc | Detailed one-dimensional seismic velocity profiles beneath the Himalayan collision zone: evidence for a double Moho? | Detailed one-dimensional seismic velocity profiles beneath the Himalayan collision zone: evidence for a double Moho? | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"김우한(경상대학교); Charlotte A. Rowe(Los Alamos National Laboratory, USA); In-Kyeong Hahm(Korea Meteorological Administration)"
] | Seismicity in the Himalaya indicates that relatively deep earthquakes (focal depth 40~100 km) occur in specific regions beneath the High Himalaya and Nepal. This study focuses on these specific regions to estimate the detailed velocity structure of the lower crust and upper mantle. We selected 202 earthquakes from the Himalaya Nepal Tibet Seismic Experiment (HIMNT) and relocated these earthquakes accurately by applying a genetic algorithm locator, GA-MHYPO (Kim et al., 2006). The detailed one-dimensional P-velocity structure is estimated based on travel-time inversion using hypocentral parameters determined by GA-MHYPO. Computational results show two velocity anomalies exhibiting upper-mantle velocities at depth of about 4550 and 60 km, respectively, beneath the High Himalayan region, whereas a single Moho exists at about 55 km depth beneath Nepal. To validate the stability of these results, a bootstrapping method was used for the inversion. | 지질학 | null | kci_detailed_000234.xml | |||
ART001647332 | oai_dc | Shear-wave velocity structure of Jeju Island, Korea | Shear-wave velocity structure of Jeju Island, Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Ki Young Kim(Kangwon National University); Myung Ho Hong(LG International Corporation, R.O. Korea)"
] | To reveal shear-wave velocity (vs) structures of Jeju Island, the spatial autocorrelation (SPAC) method was applied to microtremors recorded at six sites on the island. At each site, four 3-component portable broadband seismometers were deployed at receiver intervals of 50–5944 m in a linear or an irregular array. SPAC functions of the vertical-component data were used to obtain dispersion curves defining phase velocities of Rayleigh waves. Shear-wave velocities derived by inverting the dispersion curves were compared with core data from nearby deep wells. The inversion models around the periphery of Mt. Halla indicate the existence of a low-velocity layer (LVL) beneath the extrusive volcanic outcrops of Quaternary age. This LVL correlates with Pleistocene marine sediments of the Seoguipo and U Formations that were sampled in nearby wells. Beneath the LVL at these sites, vs increases gradually with depth in welded tuffs that overlie a Cretaceous-Paleogene granite. The horizontal-to-vertical spectral ratio method was also applied to microtremor data to estimate depths to granitic basement rocks. The depths to the granitic basement rocks increase toward the center of the island, reaching a maximum of approximately 3.2 km below the summit of Mt. Halla. | 지질학 | null | kci_detailed_000234.xml | |||
ART001647317 | oai_dc | Oxygen isotope measurements of terrestrial silicates using a CO2-laser BrF5 fluorination technique and the slope of terrestrial fractionation line | Oxygen isotope measurements of terrestrial silicates using a CO2-laser BrF5 fluorination technique and the slope of terrestrial fractionation line | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Insu Ahn(Korea Polar Research Institute, R.O. Korea); 이종익(Korea Polar Research Institute); Minoru Kusakabe(University of Toyama, Japan); 최변각(서울대학교)"
] | Here we report oxygen isotopic compositions (both 18O and 17O) of San Carlos olivine, Juan de Fuca basalt glass, garnet standard at University of Wisconsin (UWG-2 garnet), National Bureau of standard #28 quartz (NBS-28 quartz), a hydrothermal quartz from China (CQ4 quartz), chert flint standard and a serpentine measured with a CO2-laser BrF5 fluorination system installed at Korea Polar Research Institute. In addition we measured VSMOW (Vienna standard mean ocean water) and SLAP (standard light Antarctic precipitation) with the same line; a scaling factor of 1.056 was obtained to fit the measured SLAP data to the recommended value of 18OSMOW = 55.5‰. All the other data were corrected using the VSMOW-SLAP scaling factor. Majority of the samples in this work have been measured by several laboratories; our data in general agree very well with previous data. We report data using the delta prime notation, since linearity of a mass-dependent fractionation line holds in '17O vs. '18O diagram for wide range of oxygen isotopic compositions. Average '18O values and 2 standard error of means are 5.27 ± 0.04‰ for San Carlos olivine, 5.49 ± 0.02‰ for Juan de Fuca basalt glass, 5.73 ± 0.05‰ for UWG-2 garnet, 9.18 ± 0.08‰ for NBS-28 quartz, 23.14 ± 0.36‰ for CQ4 quartz, 33.97 ± 0.16‰ for chert flint standard and 0.78 ± 0.07‰ for the serpentine. Slope of terrestrial fractionation was obtained using these data, which is 0.5248 ± 0.0003 (R2 = 0.99992). | 지질학 | null | kci_detailed_000234.xml | |||
ART001647336 | oai_dc | Geomagnetic variation and its relation to microearthquakes in the seismically inactive Korean Peninsula | Geomagnetic variation and its relation to microearthquakes in the seismically inactive Korean Peninsula | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"오석훈(강원대학교)"
] | Some microearthquakes that occur in the Korean Peninsula show significant geomagnetic variation when subjected to a specialized principal component analysis, wavelet-based semblance filtering and eigenvalue analysis. In this study, the principal component analysis was used to reconstruct and predict the geomagnetic field based on the past observed magnetic fields, and the reconstructed field was compared with the field observed during the earthquake event. The wavelet-based filtering showed improved results in delineating the earthquake event’s geomagnetic variations from their background field. Finally, the change in the tendency of the eigenvalues was detected by the analysis of three components of the geomagnetic fields during the earthquake event. The basement rock of the Korean Peninsula is known to have a highly resistive electrical structure that makes it possible for small-magnitude earthquakes to generate exaggerated geomagnetic variations. This is the first study reporting the relation between these earthquake events and the geomagnetic variations observed in the Korean Peninsula. | 지질학 | null | kci_detailed_000234.xml | |||
ART001617909 | oai_dc | Role of winter waves in sand transport at the mouth of Garolim Bay, west coast of Korea | Role of winter waves in sand transport at the mouth of Garolim Bay, west coast of Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"조형래(Andong National University); 이희준(한국해양연구원); Kyeong Park(University of South Alabama)"
] | Sedimentary processes on the west coast of Korea are strongly influenced by monsoonal climate with strong northwesterly winds during winter. Sediment transport processes under winter storm waves are, however, poorly known, because of the difficulties of field observations. For the assessment of the influence of winter waves on sediment transport processes over a sand bank at the mouth of Garolim Bay, bedload transport by combined currents and waves is quantitatively estimated using the current data measured at the bay mouth and representative parameters of winter waves, and is compared with that by tidal currents alone. Our results show that high winter waves have a significant influence on the spatial pattern, the amount, and the directions of bedload transport through the bay mouth. Under the condition of combined currents and waves, bedload transport increases considerably due to the increase in bed shear stresses, particularly in shallow water depths of the sand bank. Increases in bedload transport are more pronounced during the flood current than the ebb current, resulting in a net increase of bedload transport into the bay. It is, thus, concluded that wintertime high waves reinforce sand import into the bay and probably onto the sand flats near the mouth. Our results can be applied to other bays and estuaries that have openings allowing the influence of winter waves, given that sufficient bedload sediments are available. | 지질학 | null | kci_detailed_000234.xml | |||
ART001617921 | oai_dc | Interfacial, pore geometry and saturation effect on complex resistivity of shaly sandstone: dispersion and laboratory investigation | Interfacial, pore geometry and saturation effect on complex resistivity of shaly sandstone: dispersion and laboratory investigation | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Hilfan Khairy(Universiti Teknologi PETRONAS); Zuhar Zahir Tn.Harith(Universiti Teknologi PETRONAS)"
] | The electrical evaluation of reservoir rock needs to deem several factors that really describe a subsurface condition. As confining pressure can cause either pore space of the rock to collapse or rock properties to change, a detailed identification towards the extent of the pressure and water saturation effect on electrical properties is needed. This work is mainly focused on the investigations of electrical properties on shaly sandstones, encompassing the effects of pore geometries, confining pressure, and partial water saturation on electrical properties. Here, the frequency of electrical measurement is between 1 Hz and 0.2 MHz. It is indicated that an interfacial and geometry change due to pressure is easily recognized by imaginary resistivity in low water saturation, reflecting that confining pressure will affect only small defect to pore geometry. Meanwhile in high water saturation, bulk volume conductivity is more dominant, thus making interfacial contribution negligible. From petrographic analysis of this work it is found that only pore radius distribution has a good relationship with electrical dispersion. The relaxation time and its distribution are estimated by simultaneous inversion of real and imaginary resistivity. The Cole-Cole model inversion is applied to obtain these parameters. For this purpose, the integration of Lavenberg-Marquardt and Singular Value decomposition (SVD) are used in order to avoid singularity problems. The obtainment of decreasing of relaxation time with the increasing of confining pressure reflects the reduction of the internal surface area. | 지질학 | null | kci_detailed_000234.xml | |||
ART001617891 | oai_dc | Diverse exhumation of the Mesozoic tectonic belt within the Yangtze Plate, China, determined by apatite fission-track thermochronology | Diverse exhumation of the Mesozoic tectonic belt within the Yangtze Plate, China, determined by apatite fission-track thermochronology | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Xiao-Ming Li(Chinese Academy of Sciences); Yehua Shan(Chinese Academy of Sciences)"
] | New and mostly published apatite fission-track (AFT) data are compiled to reveal the exhumation of the Mesozoic tectonic belt (MTB) within the Yangtze Plate, China. New AFT ages ranging from 51 ± 3 to 108 ± 5 Ma with mean measured track lengths between 11.8 ± 1.6 and 12.8 ± 2.0 m, are obtained for the bedrock samples collected along a southeast to northwest transect across the MTB, including the exceptional Huangling Dome in the northern Yangtze Plate. The diverse, involving the first rapid, following by a slow, and the final accelerating, cooling and inferred exhumation from the Late Mesozoic to the Cenozoic have been identified in the study region based on the AFT data and modeling. The onset of exhumation is earlier in the Huangling Dome than in the southeastern and northwestern MTB, and in the southeastern MTB than in the northwestern MTB. Similarly, the final stage of accelerating exhumation seemed to start earlier in the Huangling Dome than in the southeastern and northwestern MTB, but in the northwestern MTB than in the southeastern MTB. The diverse exhumation of the MTB should have been attributed to the far-field effect of the Pacific plate subduction in the Cretaceous to the east, and to the eastward and southeastward tectonic escape from the Tibetan plateau imposed by the India-Eurasia collision since ~55 Ma to the west. | 지질학 | null | kci_detailed_000234.xml | |||
ART001617916 | oai_dc | Homogenization analysis for estimating the elastic modulus and representative elementary volume of Inada Granite in Japan | Homogenization analysis for estimating the elastic modulus and representative elementary volume of Inada Granite in Japan | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"채병곤(한국지질자원연구원); 서용석(충북대학교)"
] | The elastic behavior of granite, which is a composite of various minerals, was calculated with consideration of fracture distribution using the homogenization theory. Microscopic and photographic analyses were conducted to measure the random distribution of the minerals and microcracks in Inada granite. A modal analysis was conducted simultaneously with the photographic analysis. The elastic homogenization theory was applied to calculate the elastic modulus of Inada granite using the results of the modal analysis. The elastic modulus that was determined using the homogenization analysis became constant when the size of the model was larger than 254.3 mm^2 (1,156 elements). The elastic modulus, which was calculated as 94.1 GPa, was lower than the experimental value by 7.3 GPa. After the distribution of the rock-forming elements and the elastic modulus were calculated, the representative elementary volume (REV) of the fine-grained Inada granite was estimated to be 254.3 mm^2 (1,156 elements). | 지질학 | null | kci_detailed_000234.xml | |||
ART001617951 | oai_dc | Assessment of groundwater corrosivity in Hamedan Province, Iran using an adaptive neuro-fuzzy inference system (ANFIS) | Assessment of groundwater corrosivity in Hamedan Province, Iran using an adaptive neuro-fuzzy inference system (ANFIS) | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Hamid Zare Abyaneh(Bu-Ali Sina University); Maryam Bayat Varkeshi(Bu-Ali Sina University); Kourosh Mohammadi(Tarbiat Modares University); Ken Howard(University of Toronto at Scarborough); Safar Marofi(Bu-Ali Sina University)"
] | The Langelier Saturation Index (LSI) and Puckorius Scaling Index (PSI) were used to study the incrustation/corrosion potential of groundwaters in Hamedan Province, Iran. The LSI and PSI indices correlated strongly with total dissolved solids (TDS) (mgL^(–1)), pH and HCO^-_3(mmolL^(–1)) as revealed by determination coefficients of 0.90 and 0.99 for LSI and PSI, respectively. Subsequently, a trained adaptive neuro-fuzzy inference system (ANFIS) was deployed to predict the corrosion behavior of water in unsampled or partially sampled locations using available total dissolved solids (TDS), pH and HCO^-_3 as input data. Excellent agreement between the ANFIS simulations and the indices determined using conventional LSI and PSI techniques confirms that modeling using the ANFIS approach will allow water corrosion potential to be determined reliably and inexpensively using only TDS, pH, and HCO^-_3 data. | 지질학 | null | kci_detailed_000234.xml | |||
ART001617939 | oai_dc | Time series modeling of the spatial distribution of soil moisture in a mountainous hillslope headwater | Time series modeling of the spatial distribution of soil moisture in a mountainous hillslope headwater | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"김상현(Pusan National University)"
] | The spatial distribution of soil moisture depth profiles on a hillslope at the headwater of a mountainous forest watershed in Korea was obtained from time series measurements performed using a refined soil moisture monitoring system. Digital terrain analysis based on intensive field surveying was applied to configure the spatial distribution of soil moisture along the steep regolith. The upslope contributing area and topographic wetness index were employed to determine the optimal locations of sensors for time domain reflectometry (TDR) monitoring along two transects. In the early autumn of 2007, 37 time series were recorded over three weeks and used as data for modeling, accounting for the known reliability of the data and the preliminary evaluation of measured soil moisture histories in the context of time series modeling assumptions. A systematic modeling procedure involving pretreatment, investigation of stochastic structure, modeling practice with heuristic repetition, and diagnostic checking was applied to selected soil moisture time series. The two transects showed differences in the distribution of the explanatory models. Transect A, covering a region of relatively fine soil texture, showed a systematic model distribution in the context of soil depth, whereas transect B across coarser soil occasionally produced inconsistent depth profile modeling results. The predictability of the models tends to reduce substantially at the outlet of the hillslope region, possibly due to active subsurface runoff generation near the channel. | 지질학 | null | kci_detailed_000234.xml | |||
ART001617930 | oai_dc | Shift in biotic response of abyssal benthic foraminifera since MIS 7 in the eastern equatorial Pacific Ocean | Shift in biotic response of abyssal benthic foraminifera since MIS 7 in the eastern equatorial Pacific Ocean | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Hiroyuki Takata(Shimane University); 김부근(부산대학교); Chan Min Yoo(Korea Ocean and Research Development Institute); Sang-Bum Chi(Korea Ocean Research and Development Institute)"
] | We investigated the late Quaternary abyssal benthic foraminiferal faunas from the upper 209 cm of sediment core (KODOS PC5101) in order to understand the biotic response of abyssal benthic foraminifera to the glacial–interglacial cycle in the eastern equatorial Pacific Ocean. Three factor assemblages were identified in the benthic foraminiferal faunas of core PC5101: the common deep-sea fauna for which there is some seasonal food supply (Factor 1 assemblage), the fauna that suffer from possible carbonate undersaturation in the deep waters of the Southern Ocean or low food supply (Factor 2 assemblage), and the fauna for which there is seasonal food supply (Factor 3 assemblage). The low Horn’s index of overlap indicates the instability of benthic faunal association during the Marine Isotope Stage (MIS) 5. There are reasonably good correlations between the Factor 1 or 2 assemblages and the CaCO3 or biogenic opal content in the earlier part of the studied interval (early MIS 5 to MIS 7), whereas there is no significant correlation in the later part (MIS 1 to late MIS 5), except for a weak correlation between the Factor 1 assemblage and biogenic opal content. It is suggested that carbonate undersaturation at the sediment-water interface on the seafloor was one of major factors that influenced benthic foraminiferal fauna at the site of our study, particularly from early MIS 5 to MIS 7. However, additional factors also affected benthic foraminifera from MIS 1 to late MIS 5. For example, enhanced periodicity of the food supply from the surface ocean (i.e., seasonality or ENSO variability) might be another factor responsible for the shift in the biotic response of abyssal benthic foraminifera deposited after MIS 5. | 지질학 | null | kci_detailed_000234.xml | |||
ART001617902 | oai_dc | Cosmogenic ^(10)Be and OSL dating of fluvial strath terraces along the Osip-cheon River, Korea: tectonic implications | Cosmogenic ^(10)Be and OSL dating of fluvial strath terraces along the Osip-cheon River, Korea: tectonic implications | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Soo Yong Lee(Korea University); 성영배(고려대학교); 신영규(국립환경연구원); 최광희(국립환경과학원); 강희철(부경대학교); 최정헌(한국기초과학지원연구원)"
] | The Osip-cheon River flows along a linear valley that runs approximately parallel to the Osip-cheon Fault. The present study was undertaken to elucidate the tectono-geomorphic evolution of the Osip-cheon Basin during the late Quaternary by employing cosmogenic 10Be surface exposure dating and optically stimulated luminescence (OSL) dating on a flight of fluvial strath terraces. Several morphometric indices (e.g., stream length-gradient index, asymmetry factor, transverse topographic symmetry factor, stream power incision) for relative tectonic activity are determined with the help of GIS analysis, suggesting minimal tilt of the blocks on either side of the Osip-cheon Fault, with displacement being mainly strike-slip. Thus, it is suggested that the Osip-cheon River is a kind of subsequent stream that follows the weakened fault-line in the center of the basin. To determine the fluvial incision rate as an equivalent to the rate of local tectonic uplift, samples for cosmogenic 10Be dating and OSL dating were collected from the surfaces of strath terraces at two different areas along the Osip-cheon River. The terraces can be divided into three groups (T1: oldest to T3: youngest) depending on the height above the present river level. According to our data, the strath terraces formed at ca. 200 ka for T1, ca. 104 ka for T2, and ca. 14 ka for T3. The fluvial incision rate was determined by dividing the height of the terraces above the river by their respective ages. The fluvial incision rate has decreased over the last 200 ka, with a maximum rate of 0.28 mm/yr occurring between T1 and T2 (i.e., ca. 200 ka to 104 ka) followed by a rate of 0.21 mm/yr for the period from T2 to T3 (i.e., ca. 104 ka to ca. 14 ka), and a minimum rate of 0.17 mm/yr since the abandonment of T3 (i.e., over the last 14 ka). Tong-ri Canyon is deeply incised up to the major knickpoint of the Mi-in Falls. Here, the rock-cut strath terraces can be divided into two groups: the farther upstream part of the Tong-ri area (Site-1) was dated to 5.5 ± 0.5 ka, equivalent to the incision rate of 0.26 mm/yr, and the downstream part of the Tong-ri area (Site-5) was dated to 18.5 ± 1.8 ka, equivalent to the incision rate of 0.23 mm/yr. Given the active upstream migration of the knickpoint (Mi-in Falls) found in the upper reach of the river, the incision rate provided by the ages of the strath terraces in the Tong-ri Canyon should be higher than that for any other reach of the river. However, the incision rate of the reach below the mouth of Tong-ri Canyon is similar to the value of the reach above the major knickpoint, suggesting that knickpoint migration in the Tong-ri area was not active during the last 18.5 ka. Rather, it seems to have advanced to a certain level of incision in the past. Along the Osip-cheon River, the values of stream power incision and stream length-gradient show a contrasting distribution. The highest and most anomalous values of these indices are found along the upstream part of the Osip-cheon River. These indices values are likely to be associated with stream piracy. Given the geomorphic features (e.g., elbow of capture, wind gap, waterfall) found in the Tong-ri Canyon area, stream piracy might have been caused by Quaternary reactivation of the Osip-cheon Fault or by the ongoing but slowing, long-term regional tectonic uplift, with an axis along the Taebaek Mountain Range. | 지질학 | null | kci_detailed_000234.xml | |||
ART001456216 | oai_dc | Some large values of in-situ stress and related engineering geological problems in China | Some large values of in-situ stress and related engineering geological problems in China | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Yanjun Shang(Chinese Academy of Sciences); 박형동(서울대학교); Yongyue Shi(Chinese Academy of Sciences); Guangxiang Yuan(Chinese Academy of Sciences); Yuanchun Sun(Chinese Academy of Sciences)"
] | In recent years, different methods have been applied to in-situ stress estimation for stability analysis of increasing large-scale tunnels in China. It was found that some extraordinary stress values are mostly associated with, although not a necessity of, engineering geological problems such as collapse, rock burst and squeezing. This paper focuses on finding the relationship among abnormal in-situ stress component values. The exposure in ground surface with unloading and erosion contributes a lot to relatively higher horizontal stress and lateral coefficient values of igneous and metamorphic rocks, while this situation is not the case for sedimentary rocks. Comparing stress data and connecting some abnormal values with typical case examples for better understanding and estimating stress is the main feature of this paper. | 지질학 | null | kci_detailed_000234.xml | |||
ART001456415 | oai_dc | Climate response over Asia/Arctic to change in orbital parameters for the last interglacial maximum | Climate response over Asia/Arctic to change in orbital parameters for the last interglacial maximum | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"김성중(한국해양연구원부설극지연구소); Jun Mei Lü(Chinese Academy of Meteorological Sciences); 이상헌(한국지질자원연구원); 최태진(한국해양연구원부설극지연구소); 김백민(Korea Polar Research Institute); 이방용(한국해양연구원부설극지연구소); 우성호(Korea Polar Research Institute); Yoojin Kim(Korea Polar Research Institute)"
] | The climate response over Asia/Arctic to the change in orbital parameters for the last interglacial maximum (LIGM) is investigated using the NCAR CCM3. After implementing LIGM orbital parameters, the insolation decreases in January and increases in July in the northern hemisphere in comparison to present values. The reduced net short-wave radiative heat fluxes in January lead to the surface cooling in low to mid latitudes of Asia, whereas a warming is obtained in northern Asia where the net short-wave radiative heat fluxes change little. The January warming in northern Asia/Arctic in the LIGM, consistent with proxy records, is mainly due to the marked increase in downward long wave heat fluxes associated with the increase in cloud and in part by the increase in the Arctic Oscillation polarity. In July, the increased insolation leads to the surface warming over most Asia, even though a slight cooling is obtained in low latitudes in spite of the increase in insolation, due to the decrease in the short-wave heat fluxes at the surface by the increase in the cloud amount. Precipitation overall increases at South and East Asia in July, due to the stronger southwest and southerly winds. The change in insolation due to the orbital parameters determines the climate change pattern in low- to mid-latitudes over Asia in the LIGM, even though the degree of climate change is much lower than suggested by proxy estimates. The results obtained in this study implies that, under the different climate background such as future global warming, the change in greenhouse effect associated with cloud feedback could play an important role in determining the climate change over Asia/Arctic. | 지질학 | null | kci_detailed_000234.xml | |||
ART001456372 | oai_dc | Carbonate diagenesis of the Late Pleistocene limestone of the Faaa M0020A core: IODP Expedition 310, Tahiti Sea Level Change | Carbonate diagenesis of the Late Pleistocene limestone of the Faaa M0020A core: IODP Expedition 310, Tahiti Sea Level Change | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"우경식(강원대학교); 윤경환(한국석유공사); 이영주(한국지질자원연구원); Tsutomu Yamada(Tohoku University); Ryuji Asami(Tohoku University); Yasufumi Iryu(Nagoya University)"
] | The diagenetic history of the pre-LGM (Last Glacial Maximum) limestone from the core by IODP Expedition 310 was investigated texturally and geochemically. The limestone is mostly deposited in reef front and fore-reef settings and mostly composed of corals, coralline algae, and microbialites with a minor contribution of green algae, mollusks, and echinoderm fragments. Relatively high abundance of microbialites is the quite distinctive feature, compared to other reefal sediments described elsewhere. Texturally, shallow marine cements are characterized by acicular and botryoidal aragonite and druse HMC, and equant LMC cements of meteoric origin are relatively rare. Presence of LMC equant cements appears to be facies-controlled, thus is dependant upon the nature of substrates. It appears that the limestone was mostly subjected to vadose meteoric diagenesis during the last glacial period. The fibrous HMC cements in vuggy pores together with their oxygen isotopic compositions and textural evidence suggest that the limestone was subaerially exposed during the last glacial period and resubmerged during deglaciation. Stable isotopic and trace elemental analyses were carried out for microbialites that were originally composed of HMC. Oxygen isotopic compositions and Fe and Sr contents of pre-LGM microbialites are clearly distinguished from those of post-LGM limestone. This suggests that the limestone had undergone meteoric diagenesis in the different diagenetic system, depending upon the magnitude of the partition coefficients of trace elements. No clear difference between unaltered (post-LGM) and altered (pre-LGM) limestone was observed for Mn, Mg, and carbon isotope, indicating a closed diagenetic system. However, the diagenetic system was semi-open with respect to Sr and oxygen isotope. In addition, enriched carbon isotopic compositions of the pre-LGM limestone may imply that vegetation cover was negligible for the formation of paleosol layers. This is also supported by poorly preserved unconformity surface with an absence of paleosol layers within the core. | 지질학 | null | kci_detailed_000234.xml | |||
ART001456331 | oai_dc | Rupture pattern of a moderate earthquake in Odaesan, Korea | Rupture pattern of a moderate earthquake in Odaesan, Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"박순천(국립기상연구소); In-Kyeong Hahm(Korea Meteorological Administration)"
] | We investigated the fault geometry and slip distribution of the 2007 Odaesan, Korea, earthquake (ML 4.8). Because of the favorable location, we could use several nearby stations for the analyses. Four foreshocks and four aftershocks were found from continuous waveform data, and their locations, including the mainshock, were aligned to the northwest~southeast direction. The source time function that was estimated by deconvolution of displacement waveforms seems to be shorter to the northwest. We could image the slip distribution using waveform inversions and found that it has two asperities, one near the hypocenter and the other relatively far from the hypocenter to the northwest. All the results are consistent with each other and represent that directivity effect exists to the northwest. Slip pattern of this event provides an evidence of complex source process of moderate earthquakes. | 지질학 | null | kci_detailed_000234.xml | |||
ART001456547 | oai_dc | The use of garnet porphyroblasts to resolve the metamorphic pressure−temperature−deformation (P−T−d) path: An example from the Imjingang belts, South Korea | The use of garnet porphyroblasts to resolve the metamorphic pressure−temperature−deformation (P−T−d) path: An example from the Imjingang belts, South Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"김형수(경북대학교); Won-Sun Jung(Korea University)"
] | Quantitative P−T−deformation path determination for metamorphic rocks can be revealed by an approach combined isopleths intersection of zoned garnet compositions with foliation intersection/inflexion axes (FIAs) preserved within the garnet porphyroblast. The method presented here is applied to metapelites in the Jingok Unit of the Imjingang belt, South Korea.
Garnet and staurolite FIA trends are E−W to WNW−ESE (90−120°)and NE−SW to ENE−WSW (50−80°), respectively. The FIA data indicate that garnet porphyroblasts have grown under N−S to NNE−SSW bulk shortening. P−T paths for garnet growth in Grt,St and Ky zone in the Jingok Unit, calculated from geothermobarometers and the intersection of isopleths on P−T pseudosections in the MnO−Na2O−CaO−K2O−FeO−MgO−Al2O3−SiO2−H2O (MnNCKFMASH)system constructed using program THERMOCALC,are compressional heating from 545 ℃ at 5.3 kbar to 610−640 ℃at 7.9−8.8 kbar. All compositional and microtextural data and thermodynamic modeling indicate that garnet porphyroblasts have formed during compressional heating under N−S crustal shortening,whereas staurolite porphyroblasts have formed dominantly during sub-isothermal decompression with overgrowing NE/ENE FIA. Consequently, the metapelites in the Jingok Unit have experienced clockwise P−T path derived from Barrovian-type metamorphism belong in amphibolites facies. | 지질학 | null | kci_detailed_000234.xml | |||
ART001456353 | oai_dc | Simulation on the cyclic operation of an open borehole thermal energy storage system under regional groundwater flow | Simulation on the cyclic operation of an open borehole thermal energy storage system under regional groundwater flow | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"이근상(경기대학교)"
] | Coupled hydrogeological-thermal simulation is performed to analyze the effect of the configuration of boreholes and operation schedule on the performance of the borehole thermal energy storage (BTES) system. This paper presents numerical investigations and thermohydraulic evaluation on the cyclic flow regime operation of open borehole thermal energy storage system under the effects of regional groundwater flow. A three-dimensional numerical model for groundwater flow and heat transport in the ground is used to determine the annual variation of recovery temperature from the thermal energy storage. The model includes the effects of convective and conductive heat transfer, heat loss to the adjacent confining strata, and hydraulic anisotropy. The operation scenario consists of cyclic injection and recovery after holding interval and four periods per year to simulate the seasonal temperature conditions. For different parameters of the system, performances were compared in terms of the variation of extraction temperature. The calculated water temperature at the producing pipe remains relatively constant within a certain range throughout the simulation period. Heat loss, injection/production rate, aquifer thickness, and permeability ratio used in the model are shown to impact the predicted temperature profiles at each stage and the recovery water temperature. The influence of pressure gradient, which determines the direction and velocity of regional groundwater flow, is substantial for all cases considered. | 지질학 | null | kci_detailed_000234.xml | |||
ART001456344 | oai_dc | Fractal analysis of the evolution of a fracture network in a granite outcrop, SE Korea | Fractal analysis of the evolution of a fracture network in a granite outcrop, SE Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Seung-Ik Park(Korea Institute of Geoscience and Mineral Resources); 김영석(부경대학교); 류충렬(한국지질자원연구원); David J. Sanderson(University of Southampton)"
] | Kinematical and fractal analyses were conducted on a fracture network in a well-exposed granite outcrop in SE Korea. The objective of this study is to examine the temporal and spatial evolution of the fracture network. From the orientation and abutting relationships of fracture sets, six fracturing events and their relative ages were established, several of which included strike-slip reactivations of earlier formed fractures. These events may be correlated with the Cenozoic to Recent evolution of the Yangsan Fault and surrounding areas. 2-D box counting analyses were performed on maps of the fracture network at the six stages of its evolution. For the earliest event D = 1.11, and represents a clustered development of fractures. Event 2 leads to a large increase of D = 1.51, with subsequent events producing a gradual increase up to 1.55 after the final event. This stabilization of the fractal dimension involved a change from the widespread development of new fractures (event 2) to the greater importance of reactivation of existing fractures, with only localized development of new fractures, usually as tip and linkage damage around pre-existing fractures. Fracture density was greatest for the event 2 fractures and increased only gradually after that. This pattern is similar to that of the fractal dimension and a good linear correlation was found between these two parameters. Although fractal dimensions and density show little change during the late stages of deformation, the fracture connectivity continued to increase due to the formation of local secondary fractures developed during reactivation of earlier formed fractures. | 지질학 | null | kci_detailed_000234.xml | |||
ART001455427 | oai_dc | SHRIMP U-Pb ages of detrital zircons in metasandstones of the Taean Formation, western Gyeonggi massif, Korea: Tectonic implications | SHRIMP U-Pb ages of detrital zircons in metasandstones of the Taean Formation, western Gyeonggi massif, Korea: Tectonic implications | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"조문섭(서울대학교); 나준석(서울대학교); 이기욱(한국기초과학지원연구원)"
] | Detrital zircons in three metasandstones of the Taean Formation, western Gyeonggi massif, Korea, were analyzed using a sensitive high-resolution ion microprobe (SHRIMP), in order to provide geochronologic constraints for the depositional age as well as the protolith ages. This formation mainly comprises the sandstone–mudstone units which experienced regional metamorphism at the transitional greenschist–amphibolite facies condition. The majority of detrital zircons yielded concordant ages defining four major age components: (1) Late Archean–Early Proterozoic (2.5–2.4 Ga); (2) Middle to Earliest Late Proterozoic (1.0–0.9 Ga); (3) Middle Late Proterozoic (820–750 Ma); and (4) Silurian (~430 Ma). The youngest group gives a weighted mean 206Pb/238U age of 431.3 ± 4.1 Ma (n = 17), confirming the Upper Paleozoic deposition of the Taean Formation. Together with this Silurian peak, the presence of Middle to Late Proterozoic ages is characteristic for the source rock, suggesting that the western Gyeonggi massif could be correlative with the South China craton. On the other hand, the lack of Paleoproterozoic age of ~1.87 Ga is in marked contrast with its predominance in the basement rocks of central to eastern Gyeonggi massif. The overall distribution pattern of detrital zircon ages is consistent with that of the Devonian metasedimentary rock in the Imjingang belt, suggesting an extension of this collisional belt towards the south. | 지질학 | null | kci_detailed_000234.xml | |||
ART001456187 | oai_dc | Glacial sea surface temperature of the East Sea (Japan Sea) inferred from planktonic foraminiferal assemblage | Glacial sea surface temperature of the East Sea (Japan Sea) inferred from planktonic foraminiferal assemblage | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"이경은(한국해양대학교); Katsunori Kimoto(Japan Agency for Marine-Earth Science and Technology); Dae Hyun Kim(Gematek Co., Ltd)"
] | In order to reconstruct the last glacial sea surface temperature (SST) of the East Sea, we investigated planktonic foraminiferal assemblage in the marine sediments of a piston core recovered from the Ulleung Basin, East Sea. For core top, the most dominant species is right coiling Neogloboquadrina incompta, while left coiling Neogloboquadrina pachyderma and Globigerina bulloides clearly dominate the glacial assemblages. Based on fauna count, we reconstructed past SST using modern analog technique (MAT) with a global dataset. However, the application of the global dataset may hinder the reconstruction of regional SST. In order to validate this, we tested for the foraminiferal assemblages of 51 surface sediments in the East Sea with MAT and the global dataset. The results show that the estimated MAT temperatures were completely different from the real SST of core top sites, indicating that MAT with the global dataset may not be applicable for the East Sea SST reconstruction. Therefore, we developed new statistical calculation method using East Sea fauna dataset only. According to this method, the glacial SST was 2℃ lower than today for August, and 6 ℃ lower for February. This glacialinterglacial change of August temperature is relatively smaller than other results, while February temperature is comparable. | 지질학 | null | kci_detailed_000234.xml | |||
ART001456255 | oai_dc | Loess record of the evolution history of severe sandstorms in the Tengger Desert during the Last Interglacial Period (MIS5) | Loess record of the evolution history of severe sandstorms in the Tengger Desert during the Last Interglacial Period (MIS5) | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Qingyu Guan(Lanzhou University); Baotian Pan(Lanzhou University); Na Li(Lanzhou University); Qiong Li(Lanzhou University); Jundi Zhang(Lanzhou University); Shujian Xu(Lanzhou University); Hongshan Gao(Lanzhou University); Jia Liu(Lanzhou University)"
] | The Shagou loess section recorded the evolution information of severe sandstorms in the Tengger Desert during the Last Interglacial (MIS 5). By analyzing the grain size data of the loess samples using the grain size class-standard deviation, we selected the grain size component between 209 and 550 µm to reconstruct the evolution history of the severe sandstorms in the Tengger Desert during the Last Interglacial. The results indicate that there were at least 12 periods of frequently occurring severe sandstorms in that location over this time period. There were two periods in each of S1SS1 and S1SS2, four periods in S1LL1, three periods in S1LL2 and one in S1LL4. The occurrence frequency and intensity of the severe sandstorms presented a characteristic increase from the early to the late period of the Last Interglacial. Combined with the calcium carbonate results, this evidence suggests that climatic change is closely related to sandstorms. A warm and wet climate could restrict the occurrence of severe sandstorms; conversely, a cold and dry climate easily induces severe sandstorms. Meanwhile, with a warm and dry climate background, the relationship between climatic change and the occurrence of sandstorms is quite complex: severe sandstorms are also able to occur in such a climate. A cold and dry climate, however, does not mean a certainty of severe sandstorms. | 지질학 | null | kci_detailed_000234.xml | |||
ART001456277 | oai_dc | Effects of suspended sediment concentration and turbulence on settling velocity of cohesive sediment | Effects of suspended sediment concentration and turbulence on settling velocity of cohesive sediment | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"하호경(극지연구소); Jerome P.-Y. Maa(College of William and Mary)"
] | Using a 5-MHz acoustic Doppler velocimeter (ADV),laboratory experiments were carried out to investigate the effects of suspended sediment concentration (SSC) and turbulence on the settling velocity (ws) of cohesive sediment. The measurement of ws with the Clay Bank sediment showed that ws increased non-linearly with SSC in the range of 300–700 mg L−1, and that turbulence can increase ws up to one order higher than ws for nonturbulent conditions. This turbulence effect can explain why ws derived by ADV is 1 to 3 orders higher than ws estimated by Owen tube where the ambient turbulence is totally blocked.
When the turbulent shear stress was higher than about 0.14 Pa,however, it contributed to tear apart flocs and reduce ws. This study suggests that ADV is a useful tool to concurrently measure the instantaneous current velocities, SSC and ws in turbulence-dominant environments without breaking up flocs and disturbing ambient flow. | 지질학 | null | kci_detailed_000234.xml | |||
ART001507561 | oai_dc | Cenozoic tectonic evolution in the western Qaidam Basin inferred from subsurface data | Cenozoic tectonic evolution in the western Qaidam Basin inferred from subsurface data | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Yadong Wang(Chinese Academy of Sciences); Junsheng Nie(Lanzhou University); Tao Zhang(Lanzhou University); Guoqiang Sun(Chinese Academy of Sciences); Xin Yang(Chinese Academy of Sciences); Yuhu Liu(Chinese Academy of Sciences); Xingwang Liu(Chinese Academy of Sciences)"
] | It is an agreement that collision of Indian and Asian plates causes uplift of the Tibet Plateau. However, great controversy exists about uplifting history and mechanisms of the Tibetan Plateau. Uplift history of the Tibetan Plateau has been well recorded in the Qaidam Basin, located in the northern margin of the Tibet Plateau. In this paper, we recognize and classify faults recorded by subsurface seismic data in the western Qaidam Basin. In addition, we reconstruct the Cenozoic deformation history of the Qaidam Basin based on balanced section of 5 seismic profiles. The results indicates that 1) Faults in the western Qaidam Basin can be classified as growth faults and non-growth faults, and the growth faults could be divided into three subcategories. 2) According to timing and manner of fault activities, faults and strata in the western Qaidam Basin could be divided into two structural layers: the lower (Lulehe Fm-Xia Youshashan Fm) and the upper (Shang Youshashan Fm-Qigequan Fm) layer. 3) The western Qaidam Basin has experienced two intensive tectonic deformations: the first phase occurs at 43.8−22 Ma (Middle Eocene−Early Miocene), which reached peak at 31.5 Ma (Early Oligocene); the second phase occurred between 14.9 and 0 Ma (Middle Miocene−Present), and the second phase is stronger than the first phase. Recognizing early fault activities confirm previous results that northern Tibet has sensed collision between the India and the Asia shortly after the collision. However, our results here emphasize that the northern Tibet has experienced another phase of shortening and uplift in the late Neogene. It was the two-stage tectonic activities that work together to produce the current Tibetan Plateau. | 지질학 | null | kci_detailed_000234.xml | |||
ART001507654 | oai_dc | Seasonal variations of particle fluxes in the northeastern equatorial Pacific during normal and weak El Niño periods | Seasonal variations of particle fluxes in the northeastern equatorial Pacific during normal and weak El Niño periods | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Hyung Jeek Kim(Pusan National University); Kiseong Hyeong(Korea Ocean Research and Development Institute); Chan Min Yoo(Korea Ocean Research and Development Institute); Sang-Bum Chi(Korea Ocean Research and Development Institute); 김부근(부산대학교); Dongseon Kim(Korea Ocean Research and Development Institute)"
] | A moored time-series sediment trap was deployed at the Korea Ocean Research and Development Institute Long-term Monitoring (KOMO) Station in the northeastern equatorial Pacific from July 2003 to June 2005. A weak El Ni–o event was recorded from June 2004 to February 2005, and normal conditions were observed in the remaining periods. The normal period was divided into two seasons based on the cycles of environmental properties in the surface ocean: cold (December–May) and warm (June–November) season. During the normal period, the total mass flux was 1.7 times higher in the cold season than in the warm season. Particularly, the CaCO3 flux was nearly three times higher in the cold season. The enhanced CaCO3 flux in the cold season was attributed to an increased foraminiferal flux, which may have influenced the seasonal variability of the total mass flux at the KOMO station. The enhanced foraminiferal flux during the cold season may have been caused by the environmental changes of the surface ocean in response to wind-driven mixing resulting in supply of subsurface nutrient-enriched water. Particle fluxes during the weak El Ni–o period were lower by 30% than those during the normal period, which was consistent with previous findings in the central and eastern equatorial Pacific. | 지질학 | null | kci_detailed_000234.xml | |||
ART001507750 | oai_dc | The role of geosciences in the assessment of low-temperature geothermal resources (N-Portugal): a review | The role of geosciences in the assessment of low-temperature geothermal resources (N-Portugal): a review | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"José M. Marques(Technical University of Lisbon); P.M. Carreira(Nuclear and Technological Institute ); J.E. Marques(University of Porto); H.I. Chaminé(Institute of Engineering of Porto); P.E. Fonseca(University of Lisbon); F.A. Monteiro Santos(University of Lisbon); H.G.M. Eggenkamp(Technical University of Lisbon);... | The aim of this paper is to review the results of the assessment of low-temperature geothermal resources (issue temperatures between 41 and 77℃) that occur in the Portuguese mainland. For this purpose, a multidisciplinary approach, including geologic, tectonic, geochemical, geophysical and isotopic (2H, 18O, 13C, 3H and 14C) techniques, was applied in order to update local and/or regional conceptual circulation models. Three case studies of N-Portugal are presented and discussed. This paper describes different low-temperature geothermal waters presenting similar hydrogeological conceptual models but rather different geochemical signatures (e.g., HCO3–Na with pH 8, HCO3/Na/CO2-rich with pH 7 and HCO3–Na with pH 9, type waters). In fact, in the studied low-temperature geothermal systems, local/regional high altitude sites associated with highly fractured rocks play an important role in conducting the infiltrated meteoric waters towards the discharge zones near the Spas. The discharge zones are mainly related to the intersection of major regional fault lineaments (and conjugate structures), responsible for creating the mineral waters ascent. In some cases, geochemical and isotopic data point out to the existence of anthropogenic contamination of some geothermal spring waters related to the intense use of fertilizers in areas of widespread agricultural practices | 지질학 | null | kci_detailed_000234.xml | |||
ART001507543 | oai_dc | Regional moment tensor determination in the southern Korean Peninsula | Regional moment tensor determination in the southern Korean Peninsula | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"이준기(서울대학교); 김성룡(서울대학교)"
] | The Korean Peninsula is a quiet region in terms of seismic activity. Although there are historical records of many large earthquakes that caused severe damage, such major events have not been frequent in recent times, with just a few small- and moderate-sized earthquakes (M≥3) occurring each year. Therefore, the precise analysis of small- to moderate-sized earthquakes is important to understand the characteristics of earthquakes in this region. Broadband seismometers have been deployed in South Korea since 1998 in continually increasing numbers. The current broadband seismic network in Korea is quite dense, and its spatial distribution is nearly homogeneous. This network provides high-quality waveform data and makes moment tensor determination of moderate-sized earthquakes possible. We have inverted regional three-component broadband seismic data for the source parameters of 26 earthquakes ranging in size from Mw 3.2 to 5.0. The moment tensor solutions obtained from time domain waveform inversion show that most of these events have strike-slip faulting mechanisms and that their pseudo P-axis directions are predominantly ENE-WSW, with an average azimuth of 72.77°. The source parameters and maximum horizontal shear stress directions obtained in this study can provide basic information that can act as a foundation for detailed seismotectonic studies and seismic hazard analyses. | 지질학 | null | kci_detailed_000234.xml | |||
ART001507592 | oai_dc | Grain size dependent rheology on the mobility of debris flows | Grain size dependent rheology on the mobility of debris flows | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Sueng Won Jeong(한국지질자원연구원)"
] | When dealing with natural geo-hazards it is important to understand the influence of flow characteristics on the submarine landslides, because the flow characteristics of fine-grained soils are most likely governed by the rheological properties. It may further relate to the mobility analysis of debris flow. Geotechnical and rheological investigation on the clay-rich materials were compared with those of silt-rich materials. For the examined fine-grained soils, the flow behavior depends on the volumetric concentration of solid and surface phenomenon, particularly for non-swelling materials. Assuming that the debris flow materials behave as the Bingham fluid, a possible relationship between geotechnical and rheological properties are proposed. From an empirical relationship between yield stress and plastic viscosity, a comparison emphasizes the grain size effect on the rheology of geomaterials encountered in various environments. The larger the particle size involved in the matrix, the lower the value of viscosity which is in the order of 10 times. Debris flow mobility with respect to rheology concerning the large particle size is emphasized. | 지질학 | null | kci_detailed_000234.xml | |||
ART001507634 | oai_dc | Fracture imaging using Image Point transform and midpoint imaging of RVSP data | Fracture imaging using Image Point transform and midpoint imaging of RVSP data | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"이창현(한국지질자원연구원); 박권규(한국지질자원연구원); Toshiyuki Matsuoka(Japan Atomic Energy Agency); Toshifumi Matsuoka(Kyoto University)"
] | An Image Point (IP) transform integrates along a hyperbolic path and converts data to a point in the IP domain so that the reflection events are accumulated to the image point for given sources in the IP domain. In addition, the image point by definition is uniquely determined and the midpoints between sources and the image points always lie on the reflector surface. Exploiting these two facts, the image point transform technique for Vertical Seismic Profile (VSP) to reverse VSP (RVSP) data is expanded to suggest a new method called the midpoint imaging method for imaging reflectors such as fractures. Applying the transform with synthetic data for Two-dimensional (2-D) models with single reflector and two reflectors, we confirm and demonstrate that the reflection events are clearly identifiable in the IP domain. The midpoint imaging method can successfully image the reflector surfaces and the dip information even with only two shot records in a simple case. | 지질학 | null | kci_detailed_000234.xml | |||
ART001507620 | oai_dc | Towards a new potential field theory of fractal objects | Towards a new potential field theory of fractal objects | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Mostafa E. Mostafa(Nuclear Materials Authority)"
] | The Potential Field Anomaly (PFA) data of the self similar Fractal Objects (FOs) include gravity and magnetic fields and potentials along with the related derivatives. These elements are calculated on grids due to buried FOs at different fractal orders. The objects have variable physical property distributions; while in magnetic, the orientation and magnitude of polarization or earth magnetic field is arbitrary. Using the structural index as Universal Fractal Order Invariant Measure, one of the contributions of this work is expressing the elements of the PFA data at any measuring point on a grid as geometric sequences in terms of the fractal order. We found that the common ratio of the sequences is equal to the Fractal Mass Ratio (FMR), a physical quantity characterizing the object. Therefore, we can interpolate the PFA data backward or forward from one fractal order to the other. This in turn allows us to directly calculate PFA data of FOs from the zero order objects equivalent to the solid sources or initiators. We conclude that the patterns of PFA data due to a self similar FO are scale-invariant and reflect the nature of this object. We express the FMR of a FO in a new equation describing the difference between the topological and fractal dimensions in terms of a linear scale. | 지질학 | null | kci_detailed_000234.xml | |||
ART001507608 | oai_dc | Salinity effects on chlorpyrifos degradation and phosphorus fractionation in reclaimed coastal tideland soils | Salinity effects on chlorpyrifos degradation and phosphorus fractionation in reclaimed coastal tideland soils | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Eui-Yong Yun(MONSANTO KOREA Inc.); 노희명(서울대학교); Goon-Taek Lee(Seoul National University); 최우정(전남대학교)"
] | We examined the effect of soil salinity on the degradation of chlorpyrifos and the residual effect of chlorpyrifos and its metabolites on soil P fractionation during 60-day aerobic incubation. A sandy loam soil (Typic Psammaquents) was collected from the Daeho reclaimed tideland and two-thirds of the soil was applied with Na salt to get three different soil salinity levels: 4.6 (low, EL), 9.7 (medium, EM), and 14.4 (high, EH) dS m–1. Estimated half-lives for chlorpyrifos degradation were 7.1 in EL, 10.0 in EM and 16.9 days in EH soils. During the degradation of chlorpyrifos in soil, microbial activity decreased by increasing soil salinity and its inhibitory effect increased with time. In contrast, the addition of chlorpyrifos did not inhibit soil alkaline phosphatase (SAP) activity, which was higher in EH than in control soils. Chlorpyrifos added at a rate of 5.0 mg a.i. kg–1 dry soil did not affect the distribution pattern of P fractions in control soils. Both an increase in soil salinity and soil sterilization increased the Ca-bound P fraction and decreased the occluded Fe + Al-bound P fraction with a significant interaction between soil salinity and sterilization. With time, the Ca-bound P fraction increased and organic- and occluded Fe + Al-bound P fractions decreased, while total-P, available-P, and non-occluded + adsorbed P fraction remained unchanged. Particularly, organic-P was mineralized more in EH than in control soils and the Ca-bound P fraction contained the highest inorganic P released. Mineralization of organic P and partitioning of released P in the recalcitrant Ca-bound P fraction increased by increasing soil salinity, while available P fraction remained unchanged, suggesting that the addition of chlorpyrifos at the currently recommended dosage level did not seem to considerably affect the available P fraction with low P leaching potential to waterways. | 지질학 | null | kci_detailed_000234.xml | |||
ART001507580 | oai_dc | Trace element variation in olivine in the Skaergaard intrusion: petrologic implications | Trace element variation in olivine in the Skaergaard intrusion: petrologic implications | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"박병준(경북대학교); 장윤득(경북대학교); 이인성(서울대학교); 김정진(안동대학교); 추창오(안동대학교)"
] | Olivine from the Layered Series (LS), Upper Border Series (UBS), and Marginal Border Series (MBS) of the Skaergaard intrusion was analyzed to examine trace element variations. In general, olivine from all three series shows similar trends in trace elements with differentiation. Ba, Cs, Rb, and Sr, acted as excluded trace elements and the transition elements, Co, Cr, Cu, Ni, Sc, Zn, and V, are included in Skaergaard olivine. Owing to the high DNi in olivine, Ni decreases with differentiation in both olivine and the calculated Skaergaard magma. The low concentration of Cr in olivine is attributable to early depletion of Cr by pyroxene crystallization. Decreases in the abundances of V and Co are related to the onset of magnetite crystallization and the separation of immiscible Co-rich sulphide. In general, calculated partition coefficients (Di) for Skaergaard olivine show similar trends in the LS, UBS, and MBS. Calculated Di’s for Sc, Cr, and Ga in olivine, progressively increase, and Di’s for Zr, Nb, Hf, Cs, Ta, Th, and U progressively decrease, with differentiation. The systematic variation in trace element contents of Skaergaard olivine during differentiation would appear to preclude the possibility of any significant injection of new magma into the chamber during differentiation. The Ni content in Skaergaard olivine systematically decreases with differentiation as would be expected if the intrusion remained a closed system. In fact, no abrupt increases are observed in the abundances of any of the transition metal in olivine during differentiation. | 지질학 | null | kci_detailed_000234.xml | |||
ART001507639 | oai_dc | Numerical modeling of groundwater flow into a radial collector well with horizontal arms | Numerical modeling of groundwater flow into a radial collector well with horizontal arms | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"이은희(서울대학교); 현윤정(서울대학교); 이강근(서울대학교)"
] | In this study, we present a new numerical model for evaluating drawdowns in the horizontal arms of a radial collector well. This model accounts for internal friction losses, which depend on the Reynolds number, and pipe roughness in the arms of the collector well. It also accounts for diverse flow regimes (laminar, transitional, and turbulent) in the arms; thus, the drawdown in the well and the groundwater influx into the well can be evaluated. This model also evaluates the effect of the roughness coefficient on the drawdown and influx distributions along the well in the case of a turbulent flow. The results obtained by using the proposed model are in good agreement with the analytical and numerical solutions presented by Hunt (2005) and Mohamed and Rushton (2006) for the flow into a horizontal well. This proves the effectiveness of the model. We also present examples of applications of the model in order to illustrate the effects of the friction factor and roughness coefficients on the drawdown and groundwater influx into the horizontal arms. The simulation results indicate that the combined effect of variations in pumping rate, friction factor, and pipe roughness leads to varying drawdown and groundwater influx distributions along the horizontal arms of the collector well. The proposed numerical model can be used for predicting well yield, identifying the origin of water pumped by a well, and designing collector well systems in a various hydrogeologic setting. | 지질학 | null | kci_detailed_000234.xml | |||
ART001483375 | oai_dc | Source parameters of the May 2, 2009 Andong earthquake in South Korea | Source parameters of the May 2, 2009 Andong earthquake in South Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Hoseon Choi(서울대학교); 노명현(한국원자력안전기술원)"
] | An earthquake occurred in the Andong area, South Korea on May 2, 2009. Korea Meteorological Administration reported its magnitude and epicenter to be ML 4.0 and (36.56°N, 128.71°E), respectively. We carried out the waveform inversion analysis to estimate source parameters of the event. The seismic moment was estimated to be 3.8 × 1014 N·m (MW 3.7). The focal mechanism is strike-slip faulting including a little weak thrust component. The direction of P-axis of the event is N70°E which is similar to the other studies on the direction of P-axis in and around the Korean Peninsula. From the spectral analysis, the moment magnitude was estimated to be MW 3.7, which coincides with that by the waveform inversion analysis. The average stress drop is estimated to be 6.5 MPa. We applied the double difference event location method with 4 events of the Andong earthquake sequence and one event on April 28, 2010. Considering nearby Andong fault systems, location results by double difference and single event location method, and focal mechanisms, the direction of causative fault may be NW−SE or WNW−ESE. | 지질학 | null | kci_detailed_000234.xml | |||
ART001483376 | oai_dc | A time-series SAR observation of surface deformation at the southern end of the San Andreas Fault Zone | A time-series SAR observation of surface deformation at the southern end of the San Andreas Fault Zone | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"조민정(연세대학교); Joong-Sun Won(Yonsei University); Sang-Wan Kim(Sejong University); Hyung-Sup Jung(University of Seoul)"
] | The San Andreas Fault (SAF) is a continental transform fault that exists as a consequence of the relative motion of the Pacific and North American Plates. Differential SAR interferometry (DInSAR) particularly with a time-series analysis is an effective tool for long-term monitoring of the SAF. Radar interferometric phase, however, contains unwanted noises originated from atmosphere as well as observation system. For studying characteristics of interferometric phase at the southern end of the SAF zone, ERS–1/2 data, acquired from 1992 to 1999, and ENVISAT data, from 2003 to the present, were utilized. Troposphere interference and orbit error were the most significant sources of errors. Since the phase noise highly correlates with topographic elevation, a simulated interferogram from topographic elevation was utilized to compensate for the tropospheric signal delay. After subtracting the simulated phase from each DInSAR interferogram, more reliable results were obtained. These results are supported by comparison with the geodetic GPS data set. | 지질학 | null | kci_detailed_000234.xml | |||
ART001483378 | oai_dc | Response of Manas River fluvial landforms to tectonic movement, at the north flank of the Tianshan Mountain, China | Response of Manas River fluvial landforms to tectonic movement, at the north flank of the Tianshan Mountain, China | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Xingmin Shi(Shaanxi Normal University); Youli Li(Xianyang Normal University); Jingchun Yang(Peking University)"
] | Manas River is the largest river at the north foot of Tianshan Mountain, and it is obvious that the landforms at the north flank of Tianshan Mountains respond to the tectonic movement. A hypothesis has been put forward that geomorphology of the north flank of the Tianshan Mountain Range is the result of active tectonic processes. Based on the filed survey and analysis, the hypothesis has been proved by the results of the research. By investigating into the evolutions of Manas River valley fold hills, alluvial fans and terraces, it is indicated that Tianshan Mountain piedmont has been constantly uplifted along with main body of Tianshan Mountain since Quaternary, and continues to be thrust from south to north, which makes the piedmont range constantly extend to the basin direction. The deformed main body also moves from south to north. Meanwhile, the alternant Pleistocene ice age and interglacial age climate also has significant impact on the current landform patterns of north piedmont of Tianshan Mountain. | 지질학 | null | kci_detailed_000234.xml | |||
ART001483381 | oai_dc | Book review: Exploring the Origin, Extent, and Future of Life [Philosophical, Ethical, and Theological Perspectives] | Book review: Exploring the Origin, Extent, and Future of Life [Philosophical, Ethical, and Theological Perspectives] | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Wooil M. Moon(서울대학교)"
] | 지질학 | null | kci_detailed_000234.xml | ||||
ART001483374 | oai_dc | Cambrian stratigraphy of the North China Platform: revisiting principal sections in Shandong Province, China | Cambrian stratigraphy of the North China Platform: revisiting principal sections in Shandong Province, China | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"조성권(서울대학교); Hyun Suk Lee(서울대학교); Jusun Woo(서울대학교); Jitao Chen(서울대학교); Duck K. Choi(서울대학교); 이승배(서울대학교); Imseong Kang(서울대학교); 박태윤(서울대학교); Zuozhen Han(Shandong University of Science and Technology)"
] | The Cambrian succession in the North China Platform comprises a mixed carbonate-siliciclastic sequence, superbly exposed in the southern part of Shandong Province, China. In order to refine the lithostratigraphy of the Cambrian succession, this paper presents detailed sedimentary logs of outcrop sections in the Jinan, Laiwu, Jining, and Linyi areas. The entire succession consists of six lithologic units: Liguan, Zhushadong, Mantou, Zhangxia, Gushan, and Chaomidian formations in ascending order. The upper boundary of the Zhushadong Formation is refined as the base of the first purple mudstone bed of the Mantou Formation. The Mantou Formation is, in turn, bounded at the top by a thick oolitic grainstone bed of the Zhangxia Formation. The upper boundary of the Gushan Formation is placed at the base of a distinct bioclastic grainstone bed of the Chaomidian Formation. The constituent members of the Zhushadong, Mantou, and Chaomidian formations are also refined. Seventeen trilobite biozones are recognized, representing the Cambrian Series 2 to the Furongian. | 지질학 | null | kci_detailed_000234.xml | |||
ART001483379 | oai_dc | Soil contamination with TCE in an industrial complex: contamination levels and implication for groundwater contamination | Soil contamination with TCE in an industrial complex: contamination levels and implication for groundwater contamination | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"조윤주(강원대학교); 이진용(강원대학교); 이명재(㈜지오그린21); 김형수(중원대학교); 이강근(서울대학교)"
] | We examined levels of soil contamination by trichloroethylene (TCE) at an industrial complex in Wonju, Korea. The examination was focused on the surrounding area of an asphalt laboratory where TCE had been used as a solvent for testing the asphalt quality. TCE contamination in soil was found at depths of 1~5 m and ranged between 0.13 and 14,702.82 mg/kg. However, the soil contamination was restricted in immediate proximity of the laboratory. Batch isotherm experiments showed that there was a linear relationship between the sorbed concentration and the aqueous TCE concentration, which is typical for non-polar organic chemicals such as TCE. The distribution coefficient (Kd) ranged between 0.375 and 0.639 L/kg and increased with depth. Considering TCE concentration in deep soil, Kd and higher groundwater level, TCE concentration in groundwater can reach up to 19.36 mg/L. In addition, highly weathered and fractured rocks, where groundwater level formed, underlain by the contaminated soil zone can facilitate vertical TCE movement and form an extensive groundwater plume in the downgradient area. As a source removal measure, the contaminated soil at the presumably hot source zone had been remediated in 2004. | 지질학 | null | kci_detailed_000234.xml | |||
ART001483377 | oai_dc | Influence of weathering on shear strength of joints in a porphyritic granite rock mass in Jechon area, South Korea | Influence of weathering on shear strength of joints in a porphyritic granite rock mass in Jechon area, South Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"우익(군산대학교); 박혁진(Sejong University); Jean-Alain Fleurisson(l'Ecole des Mines de Paris)"
] | The evolution of the shear strength of rock joints due to weathering processes is evaluated in terms of the joint wall compressive strength (JCS) and residual friction angle. Laboratory direct shear tests were performed on 32 porphyritic granite joints sampled from granitic rock slopes along a highway in the area of Jechon in South Korea. These samples were classified according to their initial weathering state and morphological conditions of the joint surface before direct shear tests. This study shows that JCS can be reduced by 20–25% of the initial JCS value for a fresh joint wall by weathering processes and that the residual friction angle depends mainly on the weathering state of the joint surface. | 지질학 | null | kci_detailed_000234.xml | |||
ART001483380 | oai_dc | Detection of inorganic chemicals in a sandy soil using TDR: Effect of probe geometry and water content | Detection of inorganic chemicals in a sandy soil using TDR: Effect of probe geometry and water content | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Min-Hee Kim(Korea University); 김동주(고려대학교); 최재우(한국과학기술연구원); 김형수(중원대학교); Chun-Sik Kim(Hanseo Engineering)"
] | Monitoring of soil contamination becomes an important issue for effective remediation of soil and groundwater. Recently time domain reflectometry (TDR) has emerged as a promising tool for monitoring soils contaminated with inorganic chemicals since concentration of these chemicals can significantly contribute to the electrical property of a porous medium such as conductance or inverse of resistance (1/R) which can be measured by TDR. In this study, we investigated a possibility of detecting two inorganic chemicals (zinc and nitrate) in a sandy soil using TDR by conducting a number of batch experiments on TDR-measured resistance for various probe geometries (length (L) = 10, 15, 25 cm; ratio of rod spacing to diameter (s/d) = 5, 6) and saturation degrees (Se = 0.1–1.0).
Column experiment was also performed to investigate the extent of input concentration which allows the detection of nitrate by TDR for various travel distances under saturated flow condition.
The results of batch experiments showed that the inverse of TDRmeasured resistance was sensitive to both probe geometry and saturation degree. The short probe (L = 10 cm) could not detect properly the electrical property in the low concentration range (0~0.5g/L) due to the higher s/d ratio and short length. This phenomenon was more pronounced for zinc than nitrate. Saturation degree also affected significantly the measurement of resistance especially for the short probe when low saturation degree (Se < 0.5) was imposed, showing incapability of detection due to the resistance higher than the upper limit (1 kΩ) of TDR measurement. Column experiment revealed that the short probe could not detect nitrate at a travel distance of 5 cm when input concentration of nitrate lower than 500 mg/L was imposed. This indicates that the long probe (L = 25 cm) is mostly recommended to use for detection of zinc and nitrate contamination whereas use of short probe is strictly limited to the condition of high water content (Se > 0.5) and input concentration higher than 2000 mg/L in the sandy soil. | 지질학 | null | kci_detailed_000234.xml | |||
ART001538600 | oai_dc | Factors controlling the air ventilation of a limestone cave revealed by ^(222)Rn and ^(220)Rn tracers | Factors controlling the air ventilation of a limestone cave revealed by ^(222)Rn and ^(220)Rn tracers | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Yong Hwa Oh(Seoul National University); 김규범(서울대학교)"
] | We monitored ^(222)Rn (half life: 3.82 d) and ^(220)Rn (half life: 56 s) activities every hour in a limestone cave, Seongryu Cave, Korea, from May to July 2010. The activities of both nuclides in this cave were highest at night and lowest during the day owing to active ventilation with outside air during the day. As the outside air temperature increased from May to July, ^(222)Rn activity increased by 2–3 times. A simple mixing model of hourly ^(222)Rn variation revealed that the ventilation with outside air decreased by a factor of 3–4 from May to July. The daily average of ^(222)Rn activities correlated well with the daily average temperature of the outside air, indicating that the ventilation with outside air is controlled mainly by outside-air density, rather than by the diurnal amplitude of the outside air temperature. Although the trend of the diurnal variation of ^(220)Rn was similar to that of ^(222)Rn, its increase from May to July was only 65%. Since the short-lived ^(220)Rn does not have any stacking effect over different days and the diffusive flux is negligible, ^(220)Rn activities indicated increases in the advective pore-air input rates of cave rocks from May to July, which are consistent with the modeling result of hourly ^(222)Rn variations. Thus, our study suggests that the dual Rn tracers provide key information on the micro- and macro air-ventilation processes of caves. | 지질학 | null | kci_detailed_000234.xml | |||
ART001538567 | oai_dc | K-Ar ages of the Quaternary basalts in the Jeongok area, the central part of Korean Peninsula | K-Ar ages of the Quaternary basalts in the Jeongok area, the central part of Korean Peninsula | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Sunyoung Ryu(Okayama University of Science); Miho Oka(Okayama University of Science); Koshi Yagi(Hiruzen Institute for Geology and Chronology); Tetsuya Sakuyama(Japan Agency for Marine-Earth Science and Technology); Tetsumaru Itaya(Okayama University of Science)"
] | The Quaternary basalts along the Chugaryeong Fault zone in central part of the Korean Peninsula are composed of two stratigraphic units in the Jeongok area, calling the Chatan and Jeongok basalts. K-Ar analyses of the mixture of the fine-grained plagioclase and anorthoclase from the 18 basalt samples were carried out to reveal the volcanic activity of the area. The results show that the Chatan and Jeongok basalts give a uniform age, giving the weighted average ages of 0.15 ± 0.01 and 0.51 ± 0.01 Ma, respectively. This reveals the age gap between the Chatan and Jeongok basalts was 360,000 years, providing a unique volcanic history for the Quaternary volcanism. The volcanism formed the two large amounts of alkali olivine basalt flows that are similar to each other in primitive chemical composition, phenocryst composition and viscosity with an interval of 360,000 years. The results also make a time constraint on the Jeongok Paleolithic Site where the Jeongok basalt occurs below the sediments containing the Paleolithic artifacts. The age (0.51 Ma) of the Jeongok basalt provides the lower limit for the age of Paleolithic artifacts. Olivine phenocrysts from both the Chatan and Jeongok basalts have significant amount of excess argon, giving apparent older ages on the whole rock K-Ar dating by previous researchers. | 지질학 | null | kci_detailed_000234.xml | |||
ART001538596 | oai_dc | Stability and correlation properties of microtremor response | Stability and correlation properties of microtremor response | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"강태섭(부경대학교); Jin Soo Shin(Korea Institute of Geoscience and Mineral Resources)"
] | This study analyzed microtremor records from four stations located at the center and vertices of an equilateral triangle with 52-m sides. The stability of the horizontal-to-vertical spectral ratio (HVSR) was estimated for 12 days of continuous records. The results showed no variation in the frequency and amplitude of the peak spectral ratio over time. Although the amplitude patterns varied slightly at each station, the peak frequencies were consistent within the small four-station array. The results suggest that slight variations in subsurface structure beneath the array may have influenced the HVSR amplitudes. The HVSR estimate had little or no dependency of meteorological variations in atmospheric pressure, temperature, wind speed, rainfall, and humidity measured at a meteorological observatory approximately 1.3 km from the array. Spatial autocorrelation (SPAC) analyses indicated that time averaging of continuous micrometer records from a single pair of stations could serve as an alternative to spatial averaging for the entire array. This result implies that, with the SPAC approach, microtremor records from a single pair of stations rather than a larger array can be applied. | 지질학 | null | kci_detailed_000234.xml | |||
ART001538581 | oai_dc | Mineralogical and geochemical studies of Ypresian marly clays and silica rocks of phosphatic series, Gafsa-Metlaoui basin, southwestern Tunisia: implication for depositional environment | Mineralogical and geochemical studies of Ypresian marly clays and silica rocks of phosphatic series, Gafsa-Metlaoui basin, southwestern Tunisia: implication for depositional environment | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Ali Tlili(University of Sfax); Mongi Felhi(Research center of Métlaoui); Nabil Fattah(University of Sfax); Mabrouk Montacer(University of Sfax)"
] | Thick Ypresian marly clays and silica rich rocks constitute the so-called interbedded facies of phosphatic series, in the Gafsa-Metlaoui basin, southwestern Tunisia. Mineralogical and geochemical investigations are carried out on selected samples from Kef Eddour section. The data obtained by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Energy Dispersive X-ray microanalysis (EDX) and chemical analysis and IR of clay fractions indicate that the bulk rock samples are composed of cristobalite-tridymite and dolomite. Observation by SEM showed the occurrence of dolomite as a well-crystallized and a weathered shape. Whereas, cristobalite-tridymite observed in the cherty bed appears as a spheres, filling the pore spaces. However, samples which contain moderately a significant amount of feldspars, clinoptilolite and pyrite occur in the upper part of Kef Eddour section. Clay minerals consist mainly of smectite, palygorskite, and sepiolite. In this clay assemblages, the N-alkane (m/z = 57) distributions, revealed that organic matter has phytoplankton and bacterial origin. The Pristane/Phytane ratio indicated that the organic matter is deposited in a reduced environment. In this latter, sulfate-reducing bacteria generate hydrogen sulfur, which is incorporated on the organic biomolecules that occurred at the lower part of Kef Eddour section. However, the high Fe activity on the depositional environment favored the occurrence of pyrite in the upper part. | 지질학 | null | kci_detailed_000234.xml | |||
ART001538578 | oai_dc | Metamorphic P-T evolution of granulites in the central Ribeira Fold Belt, SE Brazil | Metamorphic P-T evolution of granulites in the central Ribeira Fold Belt, SE Brazil | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Telmo Santos(Laboratório Nacional de Energia e Geologia); José M. Munhá(Universidade de Lisboa); Colombo C.G. Tassinari(Universidade de São Paulo); Paulo E. Fonseca(Universidade de Lisboa); Coriolano Dias Neto(Universidade de São Paulo)"
] | Pseudosections, geothermobarometric estimates and careful petrographic observations of gneissic migmatites and granulites from Neoproterozoic central Ribeira Fold Belt (SE Brazil) were performed in order to quantify the metamorphic P-T conditions during prograde and retrograde evolution of the Brasiliano Orogeny. Results establish a prograde metamorphic trajectory from amphibolite facies conditions to metamorphic peak (T = 850 ± 50 °C; P = 8 ± 1 kbar) that promoted widespread dehydration-melting of 30 to 40% of the gneisses and high-grade granitization. After the metamorphic peak, migmatites evolved with cooling and decompression to T 500 °C and P 5 kbar coupled with a_(H2O) increase, replacing the high-grade paragenesis plagioclase–quartz–K-feldspar–garnet by quartz–biotite–sillimanite–(muscovite). Cordierite absence, microtextural observations and P-T results constrain the migmatite metamorphic evolution in the pseudosections as a clockwise P-T path with retrograde cooling and decompression. High-temperature conditions further dehydrated the lower crust with biotite and amphibole-dehydration melting and granulite formation coupled with 10% melt generation. Granulites can thus be envisaged as middle to lower crust dehydrated restites. Granulites were slowly (nearly isobarically) cooled, followed by late exhumation/retrograde rapid decompression and cooling, reflecting a two step P-T path. This retrograde evolution, coupled with water influx, chemically reequilibrated the rocks from granulite to amphibolite/greenschist facies, promoting the replacement of the plagioclase–quartz–garnet–hypersthene peak assemblage by quartz–biotite–K-feldspar symplectites. | 지질학 | null | kci_detailed_000234.xml | |||
ART001538583 | oai_dc | Optically stimulated luminescence and radiocarbon dating of samples from two Palaeolithic sites (Hahwagye-ri and Hwadae-ri) in the middle part of Korean Peninsula | Optically stimulated luminescence and radiocarbon dating of samples from two Palaeolithic sites (Hahwagye-ri and Hwadae-ri) in the middle part of Korean Peninsula | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Myung-Jin Kim(Kangwon National University); 최정헌(한국기초과학지원연구원); 홍덕균(강원대학교)"
] | OSL dating on sedimentary quartz grains from two archaeological sites in Korea, called Hahwagye-ri and Hwadae-ri, was undertaken to aid archaeological interpretation for the migratory routes of the Upper Palaeolithic and Mesolithic people in Korea. The Hahwagye-ri site is located on a river terrace of the North Han river at Kangwon prefecture and the Hwadae-ri is located on a river terrace of the Imjin river at Gyeonggi prefecture, both in the central region of Korean Peninsula. From the results of excavation conducted for recent two years, archaeologists strongly suggest that these areas would be an ideal camping place with relatively long-term residence for the Palaeolithic and/or Mesolithic foragers to get food resources by means of collecting, fishing and hunting. In order to check the quartz OSL results on the sediments at those excavation sites, radiocarbon dating was also carried out on a small series of finely layered charcoal samples. The OSL ages obtained showed a good stratigraphic correlation and were found to be in satisfactory agreement with those of the radiocarbon dating, implying that the incomplete bleaching of quartz grains, which is usually observed from fluvially deposited sediments, is not significant for these samples. These consistent ages also suggest that the quartz OSL dating can provide reliable age estimates in case that there are not enough materials suitable for other conventional tools for dating archaeologically important sediment layers. The resultant ages may provide important and useful chronological information for the Upper Palaeolithic and Mesolithic culture in Korean. | 지질학 | null | kci_detailed_000235.xml | |||
ART001538598 | oai_dc | Trends of groundwater data from the Korean National Groundwater Monitoring Stations: indication of any change? | Trends of groundwater data from the Korean National Groundwater Monitoring Stations: indication of any change? | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"박유철(강원대학교); Yun-Ju Jo(Kangwon National University, Korea); 이진용(강원대학교)"
] | Widespread climate change can impact on groundwater conditions. We evaluated the groundwater data for 1996–2008 obtained from the National Groundwater Monitoring Stations (NGMS), in the context of the global warming effect. Indications of air temperature and sea level rises were evident in the period. The groundwater levels were generally decreasing and most of this decrease was attributed to increased pumping nationwide, but no indication for any effect of sea level rise on groundwater level in coastal aquifers was found. The electrical conductivity (EC) values of groundwaters were very high in metropolitan and industrial areas, which were indicative of anthropogenic groundwater contamination and progressive groundwater quality deterioration. A systematic EC rise in coastal groundwaters, as a possible result of the sea level rise, was not observed. The groundwater temperature variation was the most striking. The majority of the monitored shallow and deep groundwaters exhibited increasing trends at mean rates of 0.04–0.09 °C/yr. The widespread and prevailing increase in groundwater temperature nationwide, with increasing air temperature, is strongly indicative of the effect of global warming. The increasing trend became more distinctive every year. However, these significant conclusions require further groundwater monitoring and re-evaluation. | 지질학 | null | kci_detailed_000235.xml | |||
ART001538589 | oai_dc | Crust and upper mantle structures of the region between Korea and Taiwan by surface wave dispersion study | Crust and upper mantle structures of the region between Korea and Taiwan by surface wave dispersion study | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Kwang-Hyun Cho(Petroleum Technology Institute); How-Wei Chen(National Central University); 강익범(한국지질자원연구원); Sang-Hyun Lee(서울대학교)"
] | We have investigated the crust and upper-mantle shear velocity structures of the region between Korea and Taiwan by analyzing the path-averaged group-velocity dispersion characteristic curves derived from surface waves. The depth of the East China Sea between Korea and Taiwan is mostly less than 100 m. We selected data from earthquakes of magnitude greater than 6.0 that occurred in Taiwan from 1999 to 2007. We used data from 219 seismograms recorded at three-component broadband seismic stations in South Korea. We also used data from 19 events from South Taiwan for our study of crust and upper-mantle shear-wave velocity structures. By examining the wave period between 5 s and 100 s, the group velocities of Rayleigh waves and Love waves were inverted jointly. These waves were computed using the multiple filter technique (MFT) and using the single-station method. The inversion results from the dispersion curves provide a detailed one-dimensional velocity profile of the East China Sea. The main features of the derived velocity profile are: 1) the unconsolidated sediments surface layer shows a fairly low shear-wave velocity value; 2) the crustal shear-wave velocity increases from 2.92 km/s to 3.90 km/s, as the depth increases to 30 km; 3) shear-wave velocities in the uppermost mantle exhibit a clear low-velocity zone between 50 km and 90 km, with the velocity varying between 4.33 km/s and 3.99 km/s; 4) the variation in shear-wave velocities in the upper mantle increases with increasing depth. We can infer that the crustal structure of the study area is continental crust. The average Moho depth is 30 km beneath the East China Sea. | 지질학 | null | kci_detailed_000235.xml | |||
ART001538573 | oai_dc | Geochemistry of Neoproterozoic limestones of the Shahabad Formation, Bhima Basin, Karnataka, southern India | Geochemistry of Neoproterozoic limestones of the Shahabad Formation, Bhima Basin, Karnataka, southern India | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Ramasamy Nagarajan(Curtin University); Jayagopal Madhavaraju(National Autonomous University of Mexico); John S. Armstrong-Altrin(National Autonomous University of Mexico); Raghavendra Nagendra(Anna University)"
] | Major, trace and rare earth element (REE) geochemistry of carbonate rocks of the Neoproterozoic Shahabad Formation, southern India were studied in order to investigate the depositional environment and source for the REEs. The PAAS (Post Archaean Australian Shale) normalized REE + Y pattern of Shahabad limestones have consistent seawater-like pattern i.e., i) LREE depletion (average (Nd/Yb)_(SN) = 0.64 ± 0.08), ii) negative Ce anomaly, iii) positive Gd anomaly (average Gd_(SN)/Gd^* = 1.05 ± 0.16), iv) superchondritic Y/Ho ratio (average Y/Ho = 38.13 ± 21.35). The depletion of LREE and enrichment of HREE are clearly indicated by the (La/Yb)_(SN), (Dy/Yb)_(SN) and (Nd/Yb)_(SN) ratios, which suggest the retention of seawater characteristics in these limestones. The negative Ce anomaly reflects the incorporation of REE directly from seawater or from the pore water under oxic condition, and also reveals the mixing of two-component systems with terrigenous clay (detrital) in the marine sediments. The terrigenous input in these limestones is confirmed by positive correlation of REE with Al_2O_3, negative correlation of REE with CaO and differences in Y/Ho ratios. V, Cr, and Sc, are positively correlated with Ti, and strong positive correlation of REE with Fe_2O_3, Ni, Cr, Sc, and Y also indicate the presence of terrigenous materials in the Shahabad limestones. | 지질학 | null | kci_detailed_000235.xml | |||
ART001538593 | oai_dc | Performance of the southern Korean Peninsula seismograph network and refinement of hypocentral parameters of local earthquakes, 2004–2008 | Performance of the southern Korean Peninsula seismograph network and refinement of hypocentral parameters of local earthquakes, 2004–2008 | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Eun Hee Park(Kyungpook National University); Jung Mo Lee(Kyungpook National University, Korea); Woohan Kim(GyeongSang National University)"
] | This study evaluated the performance of the seismograph network in the southern Korean Peninsula. The average distance between stations in this network is about 25 km. According to the Gutenberg-Richter recurrence relation, the seismograph network appears to have recorded all earthquakes larger than M 2.1-2.2 that occurred in the 9-year interval from 2001 to 2009. Values of a and b were estimated as 4.383 and 0.8544 by linear regression, with standard deviations of 0.06 and 0.018, and as 4.251 and 0.8293 by the maximum likelihood method, with standard deviations of 0.08 and 0.049, respectively. The results agree within 1 standard deviation. The network performance was evaluated with respect to hypocenter estimation accuracy by two hypocenter determination algorithms: the recently refined GA-MHYPO algorithm and the LocSAT algorithm used by the Korea Institute of Geoscience and Mineral Resources (KIGAM). The algorithms were evaluated with synthetic traveltime data generated using the local velocity structure and the present network geometry. In view of the velocity structure of the southern Korean Peninsula and the a priori velocity model used by LocSAT, GA-MHYPO determines hypocentral parameters more accurately than does LocSAT by a factor of five. GA-MHYPO is able to determine epicenters of events with large azimuthal gaps, whereas LocSAT yields large errors. GA-MHYPO cannot determine the focal depths of events shallower than 10 km with the present seismograph network, but if the network had ideal 10-km spacing, GA-MHYPO could accurately determine the focal depths of 5-km-deep events. The 122 earthquakes with magnitudes larger than or equal to 2.0 that occurred from 2004 to 2008 were relocated using GA-MHYPO. The determined hypocentral parameters determined were compared with those reported by the Korea Meteorological Administration (KMA) and KIGAM. Epicenter locations differed by as much as 10 km for inland events and as much as 30 km for offshore events. This may be attributed to large azimuthal gaps in offshore events and the large differences between the a priori velocity models used by the KMA and KIGAM and the true offshore velocity structure. The focal depths determined here were quite different from those reported by KIGAM, and there were many events deeper than 15 km. No relationship with tectonic structure or geology was evident. The KMA and KIGAM could improve the accuracies of hypocentral parameters in their final earthquake reports by using a better a priori velocity model in their hypocentral determination packages. | 지질학 | null | kci_detailed_000235.xml | |||
ART001381579 | oai_dc | Detrital zircon evidence for the antiquity of Taiwan | Detrital zircon evidence for the antiquity of Taiwan | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Ching-Ying Lan(Academia Sinica, Republic of China); Tadashi Usuki(Academia Sinica, Republic of China); Kuo-Lung Wang(Academia Sinica, Republic of China); Tzen-Fu Yui(Academia Sinica, Republic of China); Kazuaki Okamoto(Saitama University, Japan); Yuan-Hsi Lee(National Chung Cheng University, Republic of China); Ta... | In-situ U–Pb geochronology and Hf isotopic studies of zircons from the Pre-Tertiary basement complex and Eocene rocks of the Central Range of Taiwan were carried out to elucidate the history of detrital zircons older than 2.3 Ga. Zircons from the eastern Backbone Range and Eastern Central Range show Paleoproterozoic to late Neoarchean ages (2.3 –³2.5 Ga), whereas those from the Hsuehshan Range yield Neoarchean to Mesoarchean ages (2.6–3.2 Ga). The εHf(T) for the Paleoproterozoic to late Neoarchean zircons varies from –7.4 to +5.1, implying both juvenile crustal growth and reworking of old crusts. This dual origin could extend back to Mesoarchean–Paleoarchean (3.0–3.4 Ga) based on Hf isotopic model ages. Consistent but narrower εHf(T) values and Hf crustal model ages for zircons from Taiwan compared to Cathaysia suggest a possible common origin for these zircons, although Taiwan has a generally younger crustal evolution history than SE China. | 지질학 | null | kci_detailed_000235.xml | |||
ART001381584 | oai_dc | Early Paleozoic medium-pressure metamorphism in central Vietnam: evidence from SHRIMP U−Pb zircon ages | Early Paleozoic medium-pressure metamorphism in central Vietnam: evidence from SHRIMP U−Pb zircon ages | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Tadashi Usuki(Academia Sinica, Republic of China); Ching-Ying Lan(Academia Sinica, Republic of China); Tzen-Fu Yui(Academia Sinica, Republic of China); Yoshiyuki Iizuka(Academia Sinica, Republic of China); Van Tich Vu(Hanoi University of Science, Vietnam); Tuan Anh Tran(National Center for Natural Sciences and Tec... | To constrain the timing of collisional event in the Indochina block, SHRIMP U–Pb dating and REE analyses of zircon were carried out for two paragneiss samples of the Kham Duc Complex, central Vietnam. Both samples contain kyanite, staurolite, and zoisite as relics from an early metamorphic stage (M1), and biotite and sillimanite as major minerals constituting the foliation formed during the late metamorphic stage (M2). The change in mineral assemblages indicates a clockwise P-T path composed of a high- or medium-P + low-T stage (M1) and a subsequent low-P + high-T stage (M2). The U−Pb concordia ages of zircon rims are 447 ± 6 Ma and 452 ± 6 Ma for the two samples, respectively. These results are distinctly different from the available Ar–Ar mineral ages of 254–225 Ma. Following the clockwise P-T path and phase equilibrium analyses of the Complex, we suggest that the zircon rims were formed near peak temperatures during the decompression. The ~450 Ma zircon rim thus gives the minimum age constraint for a possible crustal thickening event during Early Paleozoic, whereas the reported Permo-Triassic Ar–Ar ages would result from an Indosinian overprint. This Early Paleozoic event is most likely related to a collisional orogeny between the Indochina and South China blocks. Late Neoproterozoic to Neoarchean ages are recorded from detrital zircon cores of the Kham Duc Complex, the Kontum Massif and Truong Son Belt, suggesting that their protoliths might have derived from sediments at the Gondwana margin. | 지질학 | null | kci_detailed_000235.xml | |||
ART001381605 | oai_dc | SHRIMP allanite U−Th−Pb dating of bimodal Triassic metamorphism of Neoarchean tonalitic gneisses, Daeijak Island, central Korea | SHRIMP allanite U−Th−Pb dating of bimodal Triassic metamorphism of Neoarchean tonalitic gneisses, Daeijak Island, central Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"김윤섭(Korea Basic Science Institute); Chang-Sik Cheong(Korea Basic Science Institute); 이유영(Seoul National University, Korea); Ian S. Williams(The Australian National University)"
] | The microstructures, compositions and U−Th−Pb
ages of allanite from tonalitic gneisses in a Neoarchean migmatite
complex, Daeijak Island, central Korea, have been investigated.
Allanite crystals up to ~300 μm in diameter occur with accessory
apatite, ilmenite, magnetite and zircon primarily in the major
foliation defined by aggregates of biotite and hornblende. The
allanite is commonly rimmed by clinozoisite, and has a range of
oscillatory to patchy compositional zoning. Its total LREE + Th
content ranges from 0.58 to 0.83 atoms per 12.5 oxygens. The
208Pb/232Th isotopic ages of allanite from two tonalitic gneiss samples
measured using the SHRIMP II ion microprobe show the same
two age clusters, 229 ± 2 and 215 ± 4 Ma in sample DE28, and 227 ±
7 and 213 ± 4 Ma in sample DE43. The allanite 206Pb/238U ages from
sample DE28 are similarly clustered, but those from sample DE43
are consistently younger, ~185 Ma. These results, indicating a bimodal
Triassic metamorphic overprint, are in contrast to the Neoarchean
age (~2.51 Ga) of thick zircon overgrowths in sample DE28.
Allanite in both samples has retained its 208Pb/232Th crystallization
age(s) through an event that caused major Pb loss from its U−Pb
system, recording the later metamorphic history of a Neoarchean
migmatite terrane. | 지질학 | null | kci_detailed_000235.xml | |||
ART001381601 | oai_dc | SHRIMP geochronology and reaction texture of monazite from a retrogressive transitional layer, Hwacheon Granulite Complex, Korea | SHRIMP geochronology and reaction texture of monazite from a retrogressive transitional layer, Hwacheon Granulite Complex, Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Keewook Yi(Korea Basic Science Institute); 조문섭(서울대학교)"
] | Reaction textures, mineral chemistry, and U–Pb SHRIMP geochronology of monazite from the Hwacheon granulite complex were investigated to delineate the timing of granulite-to-amphibolite transition. Reaction textures of apatite and allanite surrounding partially-dissolved monazites in the transition zone (HY-23) are similar to those of symplectic hornblende and garnet corona around pyroxenes in mafic granulite at the same outcrop. The texture and chemistry of retrograde rare earth element-bearing minerals indicate that disequilibrium in metasomatic reactions and the availability of fluid during the amphibolitization contributed to the variable degrees of transition. The U–Pb age of dissolved monazite was dated at 1861 ± 20 Ma, which is indistinguishable from 1873 ± 17 Ma of unaltered monazite. On the other hand, the crystallization age of symplectic allanite is interpreted to be either Devonian or Triassic, based on Th–Pb and U–Pb ages, respectively. Thus, the synchroneity between accessory mineral growth and its microstructure such as corona or symplectite needs to be carefully assessed for unraveling the nature of tectonometamorphic events. | 지질학 | null | kci_detailed_000235.xml | |||
ART001381592 | oai_dc | Eruption age of the Kusandong Tuff in the Cretaceous Gyeongsang Basin, Korea | Eruption age of the Kusandong Tuff in the Cretaceous Gyeongsang Basin, Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"좌용주(경상대학교); 이용일(서울대학교); Yuji Orihashi(University of Tokyo, Japan)"
] | The Kusandong Tuff has been regarded as a key bed for the subdivision of the Upper Cretaceous strata in the Gyeongsang Basin. Since the Kusandong Tuff has the wide range of the K−Ar whole-rock ages (82~103 Ma) due to contamination and alteration, it is difficult to estimate the eruption age of the tuff. For the precise eruption age of the Kusandong Tuff, zircon grains from the tuff were analyzed using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The zircon U−Pb ages of the Kusandong Tuff are 97.1 ± 2.0 Ma and 97.3 ± 1.8 Ma, indicating that the tuffaceous bed formed during the middle Cenomanian. Accidental zircons in the tuff have a U−Pb age of 107.9 ± 3.0 Ma, which corresponds to the earlier Cretaceous igneous activity during the early Albian in age. | 지질학 | null | kci_detailed_000235.xml | |||
ART001381598 | oai_dc | CHIME dating and age mapping of monazite in granulites and paragneisses from the Hwacheon area, Korea: implications for correlations with Chinese cratons | CHIME dating and age mapping of monazite in granulites and paragneisses from the Hwacheon area, Korea: implications for correlations with Chinese cratons | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Kazuhiro Suzuki(Nagoya University, Japan)"
] | The basement of the Hwacheon area in the northern part of the Gyeonggi massif in the Korean Peninsula comprises granulite and gneiss complexes that are separated by an extensive mylonite zone. Granulites distant from the mylonite zone show little evidence of a retrograde overprint beyond minor growth of biotite along garnet grain boundaries. Monazite grains enclosed in garnet show a core to rim decrease in Y, and those in the matrix show a peripheral enrichment of Y on low-Y interiors. Similarly, garnet grains decrease in Y from core to rim, with peripheral Y-enrichment, which can be attributed to early to peak garnet growth and post-growth modification, respectively. The three chemical domains representing stages of monazite growth show no detectable age difference, together yielding a CHIME age of 1868 ± 24 Ma. Granulites near the mylonite zone show growth of cordierite and biotite aggregates around garnet grains, and yield Permo-Triassic monazite domains on and within predominantly Paleo-proterozoic monazite grains. Mylonitized granulites have a metamorphic overprint characterized by the growth of the sillimanite and K-feldsper assemblage at ca. 241 Ma, subsequent to ductile shearing. Pelitic gneisses in the gneiss complex contain zircon grains with Neoproterozoic detrital cores and monazite grains with unequivocal metamorphic ages of ca. 245 Ma. Geological, petrological and chronological evidence suggests differing evolutional histories between two crustal domains prior to amalgamation. The widespread occurrence of Permo-Triassic paragneisses and mylonites in the Gyeonggi massif can be explained by detachment of the metamorphosed upper crust of the South China block, which was thrust over the Paleoproterozoic granulite complex at ca. 241 Ma during the Sulu orogeny. Permo-Triassic metamorphic overprints on the latter are attributed to contact metamorphism from the hot allochthon. | 지질학 | null | kci_detailed_000235.xml | |||
ART001381570 | oai_dc | Middle Jurassic tectono-magmatic evolution in the southwestern margin of the Gyeonggi Massif, South Korea | Middle Jurassic tectono-magmatic evolution in the southwestern margin of the Gyeonggi Massif, South Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Young Seog Park(Chosun University, Korea); 김성원(Kyungpook National University, Korea); Weon-Seo Kee(Korea Institute of Geoscience and Mineral Resources); Youn-Joong Jeong(Korea Basic Science Institute); Keewook Yi(Korea Basic Science Institute); Jeongmin Kim(Korea Basic Science Institute)"
] | Sensitive high-resolution ion microprobe (SHRIMP)
U–b zircon dates and geochemical and isotopic (Sr and Nd) data
were obtained for Middle Jurassic granitoids from the Buyeo area
along the southwestern margin of the Gyeonggi Massif, South
Korea. Foliated 179 Ma granitoids are dominated by granite and
diorite, non-foliated 167 Ma granitoids include granite to alkalifeldspar
granite, and the youngest, non-foliated 165 Ma granitoids
consist of alkali-feldspar granite. The 179 Ma and 167 Ma rocks
are geochemically typical of I-type granitoids, and their LILE
enrichment and negative Nb-Ta-Ti-P anomalies are common features
of subduction-related granitoids. In contrast, 165 Ma rocks
are A-type granitoids that show HREE-enriched patterns with significant
depletions of Sr, P, Eu, and Ti. I-type granitoids dated at
179 Ma and 167 Ma have ISr = 0.7092–.7158, 0.7206–.7263 and
εNd(T) = –3.96 to –3.55, –1.47 to –9.51, respectively. A-type,
165 Ma granitoids have relatively lower ISr (0.7052) and strongly
negative εNd(T) (–0.47), reflecting melt derivation from the lower
crust. These results suggest that the formation of granitoids along
the southwestern boundary between the Gyeonggi Massif and the
Okcheon Belt took place at ca. 179–67 Ma by the subduction of
the paleo-Pacific plate. The 165 Ma post-orogenic A-type granites
intruded in an extensional setting, providing a critical time constraint
on the termination of Jurassic plutonism in South Korea.
The 179 Ma foliated granitoids are similar to syn-kinematic granitoids
in and around the Honam shear zone, indicating that ductile
shear movement may have occurred at ca. 179 Ma. Biotite K–r
ages of deformed Precambrian rocks and Middle Jurassic granitoids
from the Buyeo area generally yield ages of 144–52 Ma and
124–35 Ma. These results probably reflect pervasive reactivation
during Latest Jurassic to Early Cretaceous deformation that postdated
the main ductile shearing event along the southern boundary
of the Gyeonggi Massif. | 지질학 | null | kci_detailed_000235.xml | |||
ART001381612 | oai_dc | Apparent partial loss 40Ar/39Ar age spectra of hornblende from the Palaeoproterozoic Lapland-Kola orogen (arctic European Russia): insights from numerical modelling and multi-method in-situ micro-sampling geochronology | Apparent partial loss 40Ar/39Ar age spectra of hornblende from the Palaeoproterozoic Lapland-Kola orogen (arctic European Russia): insights from numerical modelling and multi-method in-situ micro-sampling geochronology | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Koen de Jong(Seoul National University, Korea)"
] | 40Ar/39Ar age spectra with progressively increasing
step ages are well known for metamorphic hornblende and have
been classically interpreted by partial loss of radiogenic argon by
diffusion processes during younger thermo-tectonic reworking.
Application of a number of numerical modelling tools based on
diffusion theory and that assume thermally activated loss of radiogenic
40Ar by solid-state volume diffusion suggests that staircaseshaped
age spectra of Neoarchaean tschermakitic hornblende from
the Lapland-Kola Orogen are due to argon losses of 40–50% during
reheating to 450 ± 25 oC in Palaeoproterozoic time. However, in
hornblende samples that yielded staircase-type age spectra, biotite
occurs in the matrix, as well as intimately and abundantly intergrown
with the amphibole along grain boundaries, cleavages, fractures
and other defects. Drilling of 1.5 mm diameter discs from
carefully selected hornblende grains in petrographic thin sections
permitted to minimise the effects of contaminant biotite inclusions
and/or compositional zoning of the amphibole. 40Ar/39Ar laser probe
step-heating of drilled biotite-free hornblende discs yielded flat age
spectra, suggesting absence of thermally activated radiogenic 40Ar
loss. This would imply unrealistically contrasting temperature histories
for neighbouring grains. Apparent-loss age spectra, thus,
result from differential gas release of hornblende and an included,
earlier degassing minor contamination of much younger biotite,
which had apparently not been completely eliminated from the
amphibole separate, despite careful handpicking. This is confirmed
by the Ca/K ratio spectra − a proxy for 37ArCa/39ArK − of hornblende
that are flat for drilled biotite-free hornblende grains, but initially
low for hornblende separates. A drilled disc and a separate of hornblende
from a biotite-free amphibolite did not yield apparent loss
spectra, but flat age and Ca/K ratio spectra, confirming the interpretation
of the role of biotite. | 지질학 | null | kci_detailed_000235.xml | |||
ART001381564 | oai_dc | In-situ analyses of zircon and other minerals: Contributions to the Asian geology and tectonics | In-situ analyses of zircon and other minerals: Contributions to the Asian geology and tectonics | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"조문섭(서울대학교); Chang-Sik Cheong(Korea Basic Science Institute); Hiroshi Hidaka(Hiroshima University, Japan)"
] | 지질학 | null | kci_detailed_000235.xml | ||||
ART001381566 | oai_dc | A U–Pb geochronological study of migmatitic gneiss in the Busan gneiss complex, Gyeonggi massif, Korea | A U–Pb geochronological study of migmatitic gneiss in the Busan gneiss complex, Gyeonggi massif, Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Kenji Horie(Geological Survey of Japan); Yukiyasu Tsutsumi(National Museum of Nature and Science, Japan); Hyeoncheol Kim(Korea Institute of Geoscience and Mineral Resources); Moonsup Cho(Seoul National University, Korea); Hiroshi Hidaka(Hiroshima University, Japan); Kentaro Terada(Hiroshima University, Japan)"
] | Zircon U–Pb geochronology was applied to a migmatitic gneiss in the Busan gneiss complex, Gyeonggi massif, Korea. 207Pb/206Pb ages of concordant zircon grains reveal that overgrowth rims with Th/U ratios lower than 0.1 formed at 1937 ± 6 Ma during the migmatization and mantled the inherited cores of ca. 3500–2200 Ma. The 207Pb/206Pb age of the rims is consistent with the monazite Th–total Pb age (ca. 1938 Ma), suggesting that the rims are the product of Paleoproterozoic regional metamorphism. Our zircon age data are not sufficient for discerning the tectonic affinity of the Busan gneiss complex belonging to either Gyeonggi or Yeongnam massif. However, consistency of these ages with the ca. 1930 Ma Pb–Pb age reported from the Bagdalryeong gneiss complex, Gyeonggi massif, supports the tectonic model that the Busan gneiss complex is a part of the Gyeonggi massif. Discordant U–Pb data obtained from the zircon rims (293 ± 31 Ma) and the monazite Th–total Pb age (ca. 289 Ma) suggest that the Busan gneiss complex was affected by the Early Permian regional metamorphism during the Ogcheon (Okcheon) Orogeny. Therefore, we conclude that the Busan gneiss complex is a part of the Gyeonggi massif occurring as either a basement rock of the Ogcheon (Okcheon) metamorphic rocks, or a tectonically emplaced, exotic piece affected by the Early Permian Ogcheon (Okcheon) metamorphism. In addition, our U–Pb data suggest that the Busan complex is possibly linked with the Hida–Oki terrane in Japanese Islands. | 지질학 | null | kci_detailed_000235.xml | |||
ART001381587 | oai_dc | In-situ U−Pb analyses of highly altered zircon from sediments overlying the Bangombé natural fission reactor, Gabon | In-situ U−Pb analyses of highly altered zircon from sediments overlying the Bangombé natural fission reactor, Gabon | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"Makiko Kikuchi(Hiroshima University, Japan); Hiroshi Hidaka(Hiroshima University, Japan)"
] | In-situ isotopic analyses of Pb and U in the highly
altered zircons found in the clay and black shale layers above the
Bangombé natural reactor, Republic of Gabon, were analyzed
using a sensitive high resolution ion microprobe (SHRIMP) to
understand the geological history in this area. The analyzed zircons
widely vary in the U contents ranging from <100 to 59000 ppm. To
confirm the problem on insufficient Pb/U calibration of high-U zircon
in the SHRIMP technique, 206Pb/238U isotopic ratios from the SHRIMP
analysis were compared with those from the analytical combination
of U/Pb elemental ratios by electron probe micro analyzer
(EPMA) with Pb isotopic ratios by SHRIMP. A significant deviation
was found in the 206Pb/238U data of high-U zircons between two analytical
techniques. Then, we concluded that the analytical data with
U concentrations less than 2500 ppm can be used as reliably calibrated
SHRIMP U−Pb data and those with high U concentration
greater than 2500 ppm were determined by the analytical combination
by EPMA and SHRIMP. The U−Pb data of zircons provide
chronological information on the igneous activity associated with
the basement rock formation at ca. 2.8 Ga. Moreover, nearly constant
207Pb/206Pb data corresponding to the mean age of 1959 ± 12 Ma
and wide variation of 238U/206Pb data suggest that U and Pb were
originated from 2.05-Ga old uraninite and migrated into zircon
grains independently under the recent severe weathering. | 지질학 | null | kci_detailed_000235.xml | |||
ART001329338 | oai_dc | Engineering geological investigation into rockfall problem: A case study of the Seated Seokgayeorae Image carved on a rock face at the UNESCO World Heritage site in Korea | Engineering geological investigation into rockfall problem: A case study of the Seated Seokgayeorae Image carved on a rock face at the UNESCO World Heritage site in Korea | {
"journal_name": "한국지질과학협의회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
} | [
"최요순(Seoul National University); Jong-Yoon Lee(Korea National Housing Corporation); Junyong Lee(Korea Resource Corporation); Hyeong-Dong Park(Seoul National University)"
] | This paper considers the rockfall problems around the Seated Seokgayeorae Image at the UNESCO World Heritage site in Korea. Using the Barton-Bandis (BB) model in Universal Distinct Element Code (UDEC), quantitative information on the detachment of the loose boulders was obtained. Based on the result of the field survey and laboratory tests, key parameters for rockfall simulation were determined, and then back analysis was performed to calibrate the parameters for the study site. The maximum run-out distances, bounce heights, kinetic energies and translational velocities of falling boulders were simulated using RocFall 4.0 to assess the rockfall hazard around the Seated Seokgayeorae Image to ensure both the stability of the bas-relief and the safety of tourists. The results of the analyses showed that about 80% of falling boulders in a range of 100-150 kg pass the altar with an average speed of 8.4 m/s and that the maximum kinetic energy of the falling boulders is 12.5 kJ if the boulders hit the head of the statue. Therefore, the removal of loose blocks and trees on the upper outcrop and limited rock bolting were suggested for the reduction of rockfall risk. | 지질학 | null | kci_detailed_000235.xml |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.