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The geology of Shiveet in Mongolia is composed of Paleozoic Devonian～Permian metasedimentary rock and intrusives, Mesozoic Cretaceous igneous rocks and Cenozoic sediment formation. Alluvial placer deposits developed within the survey area were deposited on the upper part of basement rocks by the intermittent transport of stream in the valley. In Urtunt and Nariin Jalga areas with the systematic prospecting, about 1m-thick gold-bearing formation were found (below the 3 m thick regolith) in the upper part of basement rocks. Fluid inclusion study was carried out in order to investigate the relevance between placer and primary gold-quartz veins within the survey area. Homogenization temperatures and salinity data of primary and pseudosecondary inclusions are 112° to 285 ℃ and 0.18 to 7.17 wt. % NaCl, respectively. Combined the result of fluid inclusion study with the fineness data (752 to 778) by electron microprobe analysis of placer gold grains, it is assumed that the primary gold deposit as a source of placer gold deposit in these areas was formed in an epithermal environment whose fluid shows a general cooling and dilution evolution with paragenetic time. However, it is thought that scrutiny on correlation between primary ore deposit and placer deposit should be preceded by additional exploration including the tracking and trenching of quartz veins.
몽골 쉬베트 지역의 지질은 하부로부터 고생대 데본기～페름기 변성퇴적암류 및 관입암체와 중생대 백악기 화성활동에 의한 화성암류, 신생대 퇴적층으로 구성된다. 조사지역내 발달하는 충적형 사금광상은 계곡부에서의 유수의 간헐적인 이동에 의해 기반암 상부에 운반 및 퇴적되었다. Urtunt, Nariin Jalga등 체계적인 탐사가 시행된 구역에서 함금층은 기반암 상부에 1m 내외의 두께로 농집부를 형성하고 있으며 표토는 대략 3 m 정도이다. 조사구역내 다수 발달하는 석영맥의 1차광상 가능성을 검토하기 위한 유체포유물 실험에서 초생 및 가2차 포유물의 균일화 온도는 112～285 ℃범위에 집중되고 NaCl상당 염농도가 0.18～7.17wt.%에 이른다. 그리고, 사금립에 대한 전자현미분석 결과, 순도(fineness)값이 752～778을 보여 기존의 연구결과 등을 종합할 때 본 사금광상의 근원으로 추정되는 1차광상의 열수유체는 전반적인 냉각 및 희석의 진화과정을 갖는 천열수 환경하에서 형성되었을 것으로 사료된다. 그러나, 1차광상과 사광상과의 상관성 검토는 석영맥에 대한 추적 및 트렌치등 추가적인 탐사가 선행된 후 언급하여야 할 것으로 사료된다.
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- Publisher :The Korean Society of Mineral and Energy Resources Engineers
- Publisher(Ko) :한국자원공학회
- Journal Title :Journal of the Korean Society for Geosystem Engineering
- Journal Title(Ko) :한국지구시스템공학회지
- Volume : 44
- No :2
- Pages :118-126
Journal of the Korean Society of Mineral and Energy Resources Engineers
