广东南雄盆地西部下俄井地区砂岩型铀矿控矿因素研究OA

The Xia'ejing area is located in the western Nanxiong basin.Therefore,it is characterized by extensive surface uranium mineralization and has favorable geological conditions for uranium mineralization,This paper focuses on discussing the ore-controlling factors and deposit genesis in the Xia'ejing area by comprehensive technical methods such as field geological survey,detailed core logging,and microscopic petrological and mineralogical identification and systematically summarizes the lithological association of sand bodies,zoning characteristics of faded alteration,ore mineralogical features,and morphological characteristics of organic matter.The results show that the sandstone-type uranium mineralization in Xia'ejing area is restricted by the faded sand body,tectonic framework and organic matter.The results indicate that the development of bleaching alteration,organic matter veinlets and polymetallic sulfide assemblages in the study area suggest that the mineralization exhibits typical exudation metallogenic characteristics.The sandstone-type uranium mineralization in the Xia'ejing area is synergistically controlled by three major factors:basement source rocks,tectonic structures,and light-colored bodies within red variegated strata.The Cambrian basement hydrocarbon source rocks act as effective uranium sources,providing uranium materials and deep-derived organic matter for mineralization.Deep and large faults cutting through the basement form efficient vertical migration pathways for deep ore-forming materials,while broad and gentle anticline folds and fracture systems constitute the migration space for lateral fluid movement.As favorable ore-hosting spaces for uranium enrichment,light-colored bodies in red variegated strata are critical prospecting indicators.It should be noticed that the uranium mineralization in this study area shows significant exudative mineralization characteristics,which represents a new type of uranium mineralization in the continental red basin in southern China.This study not only strengthen the cognition of the metallogenic mechanism of sandstone-type uranium deposits in the Nanxiong basin,but also provide an important theoretical guidance and a practical reference for the exploration and theoretical research of continental red basin sandstone-type uranium deposits in southern China.