• 文章目录 •
王果1 2， 华仁民2， 秦立峰1
WANG Guo1;2, HUA Ren-min1, QIN Li-feng2
Abstract: With rapid development of nuclear power industry in China, it is significant to investigate large economic sandstone-type uranium deposits, which are suitable for in-situ leaching mining. The existence and migration of fluid in the crust played an important role in forming most metal deposits, including sandstone-type uranium deposits which are called hydrogenic uranium deposits. Through studying some typical deposits in the Mesozoic-Cenozoic terrestrial sedimentary basins, this paper elaborates the relationship between fluid development and ore genesis in terrestrial sedimentary basins, and underlines the importance of fluid evolution history analysis. Based on the patterns of ore-forming fluid interaction, four sub-types for sandstone-type uranium deposits are proposed, i.e., basement type, brine-interface type, oxidation zone type and oil-gas type. Fluid mixing and interlayer (secondary) oxidation-reduction are two important ore-forming mechanisms. Especially, formation of sandstone-type uranium deposits of interlayer oxidation zone type is a process of superimposed unceasing reformation, which can exist up to present, until supplementation of interlayer fluids is ceased.
Sandstone-type uranium deposits originally occur as roll, tabular or pile-type ore bodies within reducing terrestrial sandstone of Late Silurian or younger ages, particularly Jurassic to Tertiary periods, while some of them also occur within red alluvial molasse formation or marine sandstone. With regard to tectonic setting, they generally occur on the stable slopes of terrestrial intermontane sedimentary basins or the margins of the central massif fold belts. The fossil channel-type sandstone uranium deposits are developed in covering strata of sub-platform districts in the margins of reactivated young platforms. Moreover, they always accompany with oil-gas provinces or regional geothermal fields, such as uranium provinces in Colorado-Wyoming of North America, Argentina of South America, and Ural-Middle Asia-Mongolia sandstone-type uranium ore belt of interlayer oxidation zone type and fossil channel type. Our conclusion shows that ore-forming fluids were originated from basement fissure water and surface water, and that some sandstone-type uranium deposits might be controlled by deep-seated thermal water system, e.g., No.382 deposit in western Yunnan Province.
Finally, some discussion is briefly given to the research methods on the ore forming fluid interactions of sandstone-type uranium deposits.
王果 ， 华仁民， 秦立峰
WANG Guo1;2, HUA Ren-min1, QIN Li-feng2. Study on Fluid Interaction of the Sandstone-Type Uranium Deposits in the Mesozoic-Cenozoic Terrestrial Sedimentary Basins[J]. J4.