| 초록 |
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. |
