Uranium Metallogenic Conditions And Metallogenic Prognosis In The Hengshan-Fuxian Area,Eastern Ordos Basin

Hengshan-Fuxian area is located in the eastern part of Ordos Basin.The degree of uranium prospecting in this area is low,especially for the deep uranium mineralization.This area is similar to Diantou and Dongsheng areas in stratigraphy,structure,lithology,lithofacies and epigenetic alteration conditions,and has the conditions to form paleo-interlayer oxidation zone sandstone-type uranium deposits.By conducting field route geological survey,drilling verification,sample analysis and testing,comprehensive research,and comparing the metallogenic conditions and mineralization characteristics of Diantou and Dongsheng uranium deposits,the characteristics of target strata structure,uranium source,lithology-lithofacies,hydrogeology and interlayer oxidation zone in the area are roughly identified,and the favorable areas for uranium mineralization are predicted.This paper is comprehensively analyzed the uranium metallogenic conditions,mineralization characteristics and metallogenic potential in the working area.It is recognized that the tectonic uplift during the late Jurassic and late Cretaceous is beneficial to the formation of uranium mineralization in the purple-red paleo-interlayer oxidation zone and gray-green alteration zone.The ancient metamorphic rock series and granitic bodies around the basin can provide uranium source for basin sedimentation.The Zhiluo formation is moderately buried with sandstone-mud interbedded structure.The sandstone body is mainly gray and gray-green medium-fine grained sandstone.The main body is meandering river bed subfacies and floodplain subfacies.It has favorable stratigraphic structure,lithofacies lithology and sand body conditions for uranium mineralization.The water quality types and mineralization degree of the confined water in the Zhiluo and Yanan formation are favorable for uranium mineralization.A certain scale of purple-red paleo-interlayer oxidation zone has been developed in the Hujiata section of the northern part of Diantou,and has a good zoning.Uranium mineralization and anomaly have been formed in the transition zone between oxidation and reduction,which is favorable for uranium mineralization.It is comprehensively analyzed and predicted that the Hujiata section is a grade III prospect area of paleo-interlayer oxidation zone type uranium mineralization and the Fuxian section is a grade III prospect area of gray-green alteration zone type uranium mineralization.