• 한국지구물리탐사학회:학술대회논문집
• /
• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
• /
• pp.344-351
• /
• 2003

Hydrogeological survey and geochemical analysis were carried out in Phra Yun area, Northeast Thailand, which is a typical salt-affected area for an understanding of hydrogeological groundwater behaviours. Geological survey reveals the presence of G1 and F1 faults. Electromagnetic ground conductivity prospecting shows that the high conductivity zones of 15 mS/cm or more are distributed at underground of the G1 and F1 faults where saline groundwater is discharged. The distribution patterns of tritium concentration show that high tritium concentration zones of groundwater were recharged from pond and river. On the assumption that the annual average tritium concentration of precipitation in Northeast Thailand is same as tritium concentration of precipitation in Tokyo and groundwater flows as piston flow, the age of recharging precipitation of groundwater with 15 TU in 1997 could be estimated at 1967-1970 years. The velocity of groundwater flow was calculated to be $5.3{\times}10^{-7}\;m/s\;and\;2.1{\times}x10^{-6}\;m/s$ respectively from a duration time of 30 years and distance of groundwater flow 500m -2000m from the pond and river to the investigation wells. Because the estimated values of velocity of groundwater flow are compatible with the hydraulic conductivities, it is considered that 30 years is a reasonable period for recharging groundwater.

• 한국지구물리탐사학회:학술대회논문집
• /
• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
• /
• pp.515-517
• /
• 2003

In order to assess the risk of adverse health effects on human exposure to arsenic and heavy metals influenced by past mining activities, environmental geochemical surveys were undertaken in the abandoned metal mine areas (Dongil Au-Ag-Cu-Zn, Okdong Cu-Pb-Zn, Songcheon Au-Ag, Dongjung Au-Ag-Pb-Zn, Dokok Au-Ag-Cu and Hwacheon Au-Ag-Pb-Zn mines). Arsenic and other heavy metals were highly elevated in the tailings from the Dongil, the Songcheon and the Dongjung mines. High concentrations of heavy metals except As were also found in tailings from the Okdong, the Dokok and the Hwacheon mines. These significant concentrations can impact on soils and waters around the tailing dumps. Risk compounds deriving from mine sites either constitute a toxic risk or a carcinogenic risk. The hazard index (H.I.) of As in the Dongil, the Okdong, the Songcheon and the Hwacheon mine areas was higher value more than 1.0. In the Okdong and the Songcheon mine areas, H.I. value of Cd exceeded 1.0. These values of As and Cd were the highest in the Songcheon mine area. Therefore, toxic risks for As and Cd exist via exposure (ingestion) of contaminated soil, groundwater and rice grain in these mine areas. The cancer risk for As in stream or ground water used for drinking water from the Songcheon, the Dongil, the Okdong, the Dongjung and the Hwacheon mine areas was 3E-3, 8E-4, 7E-4, 2E-4 and 1E-4, respectively.

• 자원환경지질
• /
• 제26권2호
• /
• pp.155-166
• /
• 1993

Gold contents with major and trace elements have been determined in 67 fresh igneous and altered wall rocks in the acid-sulfate alteration zone of the Ogmaesan-Seongsan pyrophyllite deposits in the Haenam area of the south-western part of Korean peninsula. The results are as follows; (1) Li contents have a tendency to show high value in dickite and altered rocks with dickite, while As, Mo and Sb contents have tendencies to show high values in alunite vein and silicified zone. F contents are higher in the altered rocks compared to fresh rocks. (2) Gold contents are enriched in alunite vein and silicified zone of the Seongsan deposit, but depleted in dickite and altered rock with dickite. Gold contents are especially concentrated in fault or conjunction area of two faults. (3) Gold contents are higher values in the mineral assemblages of alunite-quartz-pyrite and alteration zone of the Seongsan deposit among the studied deposits. (4) Gold contents in samples of silicified zones tend to show positive correlations with Ag, As, Co, Hg, Sb and V content, but negative correlations with Y and Zr contents, while on the other gold contents of silicified tuffs tend to show positive correlations with Hg and Sb contents. Therefore it is important to survey alunite vein and silicified zone at the conjunction of faults, and to analyze pathfinder elements such as Ag, As, Hg and Sb for geological and geochemical exploration of gold in the studied deposits.

• 자원환경지질
• /
• 제56권3호
• /
• pp.343-363
• /
• 2023

인도네시아 술라웨시는 니켈 라테라이트 광상의 세계적인 산출지로 인도네시아 니켈산업의 급속한 성장을 견인하고 있다. 활성경계부 지구조환경과 열대우림기후 그리고, 세계적 규모의 동부 술라웨시 오피오라이트(ESO)로부터 니켈 라테라이트 광상이 형성되었다. 술라웨시에 부존하는 니켈 라테라이트 광상의 특성을 이해하는 일은 니켈자원 탐사에 있어 매우 중요하다. 이 논문에서는 술라웨시 5개 지역에서 수행된 니켈 라테라이트 광상 탐사사례들을 보고한다. 지표지질조사, 트렌치 및 채굴적 단면조사, 암석기재, 전암화학 분석 및 시추탐사자료 해석 등 다양한 탐사활동들을 토대로 술라웨시 니켈 라테라이트 광상에 대한 지역별 특성들을 보고한다. 인도네시아 니켈산업의 요충지인 '남동부-암'(Southeast-Arm) 북동부에 위치하는 모롬보와 모로왈리 지역에서는 오피오라이트가 광역적으로 분포하고, 전형적인 사프로라이트형 광상이 고품위로 부존한다. 지형기복이 니켈 품위와 광체 기하를 제어하며, 절리와 가니어라이트맥이 조밀한 곳에서 고품위로 산출되는 경향이 있다. 남동부-암 남부 티낭게아와 남팔랑가 지역에서는 신생대 퇴적층으로 구성되는 오버버든(overburden)이 니켈 라테라이트 광상 상위로 놓이므로 탐사 시에 파악해야 할 주요 인자이다. 오버버든에도 불구하고, 가니어라이트맥과 함께 함니켈-사문석류로 구성되는 고품위 사프로라이트형 광체가 10 m 내외 두께로 발달하여 경제성을 확보한다. 이와 달리, '동부-암(East-Arm)' 북부 암파나 지역은 니켈 라테라이트 광상이 저품위로 부존하며, 라테라이트 프로파일이 미성숙하다. 이는 지구조 융기에 따른 삭박률이 니켈 라테라이트 광상의 형성 속도를 앞지른 결과로 생각된다. 이 논문에서 다루어진 탐사사례들은 니켈 라테라이트 광상의 부존특성과 광화 규제요인의 유기적인 상호작용을 보여준다.

• Spatial Information Research
• /
• 제14권1호
• /
• pp.129-150
• /
• 2006

본 연구에서는 GIS 및 확률 기법을 이용하여 광상의 위치와 지질, 지화학 및 지구물리 자료들 간의 상관관계를 분석하고, 광상부존가능도(Mineral potential map) 작성 및 검증을 수행하였다. 연구지역은 1:25만 강릉도폭지역 a이며, 구축된 데이터베이스 자료는 1:25만 광상분포도, 지화학도, 지질도, 부우게 중력이상도, 자력이상도이다. 본 연구에 사용된 광상은 퇴적기원의 비금속광상(고령토, 도석, 규석, 운모, 연옥, 석회석, 납석)이다. 원소별 지화학도 작성은 채취된 각 시료 3,595개의 원소별 분석치를 이용하여 IDW 보간법으로 만들었다. 구축된 지화학도는 Al, Alkalinity, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Si, Sr, V, W, Zn, $Cl^-,\;F^-,\;{NO_2}^-,\;{NO_3}^-,\;{PO_4}^{3-},\;{SO_4}^{2-}$, pH, Eh 및 Conductivity로 총 32개이다. 이러한 광상과 관련 요인들 간의 상관관계는 확률기법인 weight of evidence를 적용하여 계산하였고, 이를 바탕으로 광상부존가능도를 작성하였다. 광상부존가능도는 wieght of evidence의 W+와 W- 값을 GIS 중첩분석에 적용하여 작성하였다. 계산된 광상부존가능지수는 기존 광상부존가능성을 정량적으로 설명하고 표현하며 검증할 수 있는 값이다. 각 기법을 이용하여 작성한 광상부존가능도의 검증결과는 85.66%의 정확도를 나타내었다.

• 한국지구물리탐사학회:학술대회논문집
• /
• 한국지구물리탐사학회 2009년도 특별 심포지엄
• /
• pp.57-65
• /
• 2009

Selection of good mineralized area is a combination of the integration of all the available geo-scientific (i.e., geological, geochemical, and geophysical) information, extrapolation of likely features from known mineralized terrenes and the ability to be predictive. The time-space relationships of the hydrothermal deposits in the East Asia are closely related to the changing plate motions. Also, two distinctive hydrothermal systems during Mesozoic occurred in Korea: the Jurassic/Early Cretaceous deep-level ones during the Daebo orogeny and the Late Cretaceous/Tertiary shallow geothermal ones during the Bulguksa event. Both the Mesozoic geothermal system and the mineralization document a close spatial and temporal relationship with syn- to post-tectonic magmatism. The Jurassic mineral deposits were formed at the relatively high temperature and deep-crustal level from the mineralizing fluids characterized by the relatively homogeneous and similar ranges of ${\delta}^{18}O$ values, suggesting that ore-forming fluids were principally derived from spatially associated Jurassic granitoid and related pegmatite. Most of the Jurassic auriferous deposits (ca. 165-145 Ma) show fluid characteristics typical of an orogenic-type gold deposits, and were probably generated in a compressional to transpressional regime caused by an orthogonal to oblique convergence of the Izanagi Plate into the East Asian continental margin. On the other hand, Late Cretaceous ferroalloy, base-metal and precious-metal deposits in the Taebaeksan, Okcheon and Gyeongsang basins occurred as vein, replacement, breccia-pipe, porphyry-style and skarn deposits. Diverse mineralization styles represent a spatial and temporal distinction between the proximal environment of sub-volcanic activity and the distal to transitional condition derived from volcanic environments. However, Cu (-Au) or Fe-Mo-W deposits are proximal to a magmatic source, whereas polymetallic or precious-metal deposits are more distal to transitional. Strike-slip faults and caldera-related fractures together with sub-volcanic activity are associated with major faults reactivated by a northward (oblique) to northwestward (orthogonal) convergence, and have played an important role in the formation of the Cretaceous Au-Ag lode deposits (ca. 110-45 Ma) under a continental arc setting. The temporal and spatial distinctions between the two typical Mesozoic deposit styles in Korea reflect a different thermal episodes (i.e., late orogenic and post-orogenic) and ore-forming fluids related to different depths of emplacement of magma (i.e., plutonic and sub-volcanic) due to regional changes in tectonic settings.

• 한국지구물리탐사학회:학술대회논문집
• /
• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
• /
• pp.544-547
• /
• 2003

The objective of this study is to investigate the contamination levels and dispersion patterns of arsenic and heavy metals and to estimate the bioaccessible fraction of the metals in soil and plant samples in the vicinity of the abandoned Songcheon Au-Ag mine. Tailings, soils, plants (Chinese cabbage, red pepper, soybean, radish, sesame leaves, green onion, lettuce, potato leaves, angelica and groundsel) and waters were collected around the mine site. After appropriate preparation, all samples were analyzed for As, Cd, Cu, Pb and Zn by ICP-AES and ICP-MS. Elevated levels of As and heavy metals were found in tailings. Mean concentrations of As in agricultural soils were higher than the permissible level. Especially, maximum level of As in farmland soil was 513 mg/kg. The highest concentrations of As and Zn were found in Chinese cabbage (6.7 mg/kg and 359 mg/kg, respectively). Concentrations of As, Cd, and Zn in most stream waters which are used for drinking water around this mine area were higher than the permissible levels regulated in Korea. Maximum levels of As, Cd and Zn in stream waters were 0.78 mg/L, 0.19 mg/L and 5.4 mg/L, respectively. These results indicate that mine tailings can be the main contamination sources of As and heavy metals in the soil-water system in the mine area. The average of estimated bioaccessible fraction of As in farmland soils were $3.7\%$ (in simulated stomach) and $10.8\%$ (in simulated small intestine). The highest value of bioaccessible fraction of metal in farmland soils was $46.5\%$ for Cd.

• 자원환경지질
• /
• 제26권4호
• /
• pp.445-454
• /
• 1993

The Keumseongsan caldera is composed of the Cretaceous sedimentary rocks of the Gyeonesang Supergroup, volcanic rocks of the Yucheon Group and basic dykes. The Keumseongsan caldera is formed by subsidence of volcanic rocks, and arc fault developed late. Also, synistral strike-slip fault ($N60^{\circ}W$) developed. Volcanic rocks belong to subalkaline rocks and calcalkaline magma series. First tuffaceous breccia erupted before 71.4 Ma and cavity of magma chamber caused subsidence, which formed arc fault. Basaltic lava erupted at 71.4 Ma and residual fluids containing Fe, As, Pb, Zn and Cu metal elements built the Ohto deposits, which are dated to be 70.5 Ma based on K-Ar age for sericite. Tuffaceous breccia and tuff erupted between 70.5 and 67 Ma. When volcanic eruption became weakened, cavity in site of magma chamber brought subsidence. Rhyolite intruded and erupted at 67 Ma, and intrusive rhyolite intruded according to arc faults, also. Hydrothermal fluids containing Fe, As, Pb, Zn, Cu, Sb, Bi, Au and Ag formed the Tohyeon deposits. K-Ar age for sericite from the Tohyeon mine gives 66.0 Ma. Results of field exploration, geochemical analyses of volcanic rocks support mineralization possibility by volcanism. Especially, age of volcanism and mineralization are well in coincidence with results of K-Ar age dating. By these results, Ohto Cu mineralization is regarded to be associcated with basaltic rocks, while Tohyeon Cu mineralization with rhyolitic rocks.

• 기술혁신학회지
• /
• 제14권1호
• /
• pp.60-84
• /
• 2011

본 연구에서는 연구개발 사업에서 기술가치평가의 중요성 및 필요성을 인식하며, ANP(Analytic Network Process)기법을 적용하여 연구개발 사업으로 추진되고 있는 가스하이드레이트 개발 사업의 기술향상도를 평가하였다. ANP 방법은 요인들간의 상호 종속성 및 네트워크를 고려하여 연구개발 사업을 통해 개발된 기술의 가치를 평가 할 수 있다는 장점이 있다. 가스하이드레이트 개발사업의 기술향상도 평가를 위하여 사업의 4개 기술 분야 별 전문가의 자문 및 설문 결과를 바탕으로 기술향상도에 영향을 미치는 속성을 선정하였고, 각 속성 및 대안의 상호 종속성 관계를 고려한 네트워크 구조도를 도출하였다. ANP 기법을 적용하여 가중치 행렬을 도출한 결과 네트워크 구조도에서 보여지는 상호 관계를 확인할 수 있었다. 이러한 속성간 네트워크 관계는 기술가치평가에서 ANP 방법의 적용의 당위성을 제공해 준다. 기술향상도를 나타내는 요인의 극한 가중치 도출 결과에서는 모든 기술에서 실현 가능성이 가장 높게 평가되었다. 1위 이외에 다른 속성의 순위 및 기술향상도의 평가에서는 사업 수행 전 기술의 수준에 따라 영향을 받는 것으로 분석되었다.

• 자원환경지질
• /
• 제31권2호
• /
• pp.101-110
• /
• 1998

The purpose of this study is to elucidate the source of U anormaly formed in stream water of the drainage system around the Shinbo talc mine area based on the hydrochemical properties of water masses including surface water and groundwater. The hydrochemical properties of water masses in the Shinbo talc mine area are divide into three types; Type I : $Ca(Mg)SO_4$ type with high U content as shown in the stream water flowout from the mine, Type II : $Ca(HCO_3)_2$ type with high U content as in deep groundwater, Type III : $Ca(HCO_3)_2$, type with low U content as in the other stream water and shallow groundwater. It is necessary to emphasize that in deducing the uranium source, a distinct discrimination between type I and type II is showed in their hydrothermal properties in spite of commonly having a high uranium content, which in turn means the occurrence of a different water-rock interaction processes between both type. All evidences suggest that type II groundwater have acted as a primary media in the transport of uranium and that, as the groundwater flows through the talc mineralization zone, water composition of type II was transformed into that of type I water as the results of a secondary water rock interaction process, caused by imposition of new mineralogically controlled thermodynamic constraints. Consequently, in the viewpoint of hydrochemical exploration, the investigation of the hydrologic circulation system and the hydrogeologic properties for the aquifer of type II groundwater shall be done first of all and will provide a crucial clue on tracing the uranium mineralization zone occurred in the Shinbo talc mine area.