Study On Evolvement In Mesozoic Group And Geological Information About Snadstone-type Uranium Deposits In South Of Ordos Basin

Ordos Basin, about 250,000 km2 ,one of the biggest depression in our country, possesses abundant potential reserves of petroleum,natural gas and charcoal , is the large depression island developing in Mesozoic Era.In recently years ,with the breaking in Snadstone-type uranium deposits ,some medium small sized were discoverde in the basin,showing good foregroug in uranium depotits. Therefore, more thorough meticulous of research is necessary in nuclear energy development in basin . By synthetically using data of seism and well-logs and combining with basin construct and evolution history, sedimentary facies in this area are fallen into 6 types: alluvial-fan facies, delta facies, lacustrine facies, braided stream facies and wind facies . Ordos basin Orogenic belt of QinLing and fold belt western affected the structural evolution of Ordos basin in Mesozoic Era,developed three foreland basins and four uplift ,formatting slope zone that is advantage uranium deposit . Based on the theory of petrology and the combination of thick and thin facies, through the observation of rock core and analysis of rock slices, and other ways such as scan electronic microscope, electric probe and X-ray analysis, etc., the rock of this area is fallen into six types: clastic rock (conglomerate, mid-coarse sand stone, fine sand stone and silt sand stone), shale and carbonate rocks. Concentrating terrane in uranium respects on not only component of sedimentary facies and rock but also diagenism,during diagenetic evolution process ,some diagenism including chemical erosion,redoxomorphism,authigenic mineral and so on optimizes structure of Concentrating terrane.Basing on the character of structure and texture ,we divede â… ,â…¡,â…¢,â…£four type of concentrating terrane of uranium,thereinto â…¡,â…¢kinds concentrating terrane are the best of all.There are many good conditions in Sandstone-type uranium deposits in Ordos basin: slope zone; covering strata cropping out all ready; plentiful ore sandstone mass ; deacidizing material abundance. Founded pattern of formatting Snadstone-type uranium deposits .