The Uranium Mineralization Characteristics Research Of The Liu Huang Gou Area In The Southern Margin Of Junggar Basin

Junggar basin is one of the most important energy basins in china. It has some uranium mines, but no a big uranium deposit in the Liu Huang Gou area of the southern margin of Junggar basin. In this paper,based on regional geology and mine geology,the tectonic setting of Liuhuanggou area, U mineralization by petrography, mineragraphy, geochemistry of petrrogoy and ore deposit conduct the research of the apatite fission track and the fluid inclusions are studied.1Based on the research of petrography, mineragraphy, X ray whole rock analysis. Uranium mineralization sandstones was consists of quartz sandstone, feldspar and small amounts of clay minerals and other components in the LiuHuangGou area and most of clay minerals were deposited with the sandstone, partly resulting from the epifenetic alteration. Kaolinite as the most part of clay minerals, Illite, Iillite and smectite mixed-layer in the Jurassic formation of the LiuHuangGou area. The research of SEM and Electron microprobe show that The form of uranium minerals are finely distributed in the cracks of small particulate mineral or closely associated with sulfides film-like in the debris particles.2Based on the research of Fluid inclusions, Fluid inclusions in the uranium mineral-hosting sandstone under microscope are predominantly petroleum inclusions, composed mostly of liquid hydrocarbon inclusions with minor hydrocarbon-bearing brine inclusions. the homogenization temperature of the uranium mineral sandstone fluid changes from50℃to110℃, and the salinity varies from0.35to21.33(wt%NaCl) indicating a kind of low temperature and low salinity ore-forming fluid. the mineralization pressure varies from60.48×105Pa to93.951×105Pa, and the mineralization depth varies from0.206to0.27Km. so the mineralization depth is very lowly, uranium mineralization was ground water oxidation zone type in the liu huang gou area3Studies of C-and O-isotopic compositions of calcite in the fault zone (δ13CV-PDB=-25‰to--6.7‰,δ13OV-SMOW=11.1‰to-18.9‰)and its geochemical characteristics reveal that the ratio of light and heavy rare earth is high, concentrate light rare earth and Eu presents a positive anomaly. It’s similar with the carbonate rock formed in mostly hydrothermal deposit. CO32-or CO2in fluid were from ade-hydroxyl group of organic matter, the dissolution of marine carbonate and evolution of organic matter in deep basin.4According to the apatite fission track dating, Liuhuanggou has experienced an uplifting processing of period of time and phase of the complex that mainly include rapidly uolift stage in Late Jurassic to Early Cretaceous, a stable or weak subsidence stage in Late cretaceous to Late Oligocene and a rapidly uplift stage in Miocene. Intense tectonic movements may cause the uranium ore body which earliy formed to suffer erosion or modification. And the movement of oil-gas increase the content of restore in objective layer. As permeating and recharging function of the uranium-oxygen contained water, a certain scale of uranium mineralization enrich on the edge of the basin and tectonic uplift belt in the core area.Based on field observation, together with the previous study, we found that uranium mineralization is closely relation to tectonic evolution, oli reduction, groud water oxidation and other factors superimposed in the many formation of liu huang gou area. Our study on the structural feature and evolution of the piedmont area, the alteration type of the rock, the composition of rock, the regular pattern of the uranium mineralization and the key ore-controlling factors can provide the theoretical foundation to trace the same type uranium deposits.