塔里木盆地库车坳陷日达里克地区库车组下段沉积特征、后生蚀变及与铀成矿关系研究OA

Ridarik area in Kuqa depression,as an important case of urranium prospecting breakthrough of Neogene at the northern margin of Tarim basin,provided the basis for uranium exploration in Neogene of the whole Tarim basin.In order to better understand the sedimentary characteristics of the lower member of the Kuqa formation in the Ridarik area and the relationship between epigenetic alteration of sand bodies and uranium mineralization and establish a uranium metallogenic model to predict the favorable area.This paper systematically summarizes the characteristics of stratigraphic development in the study area,clarifies the internal relationship between uranium mineralization and sedimentary facies and epigenetic alteration through a large number of field investigations,borehole lithology observation and sample test results and comprehensive analysis.The results show that the fan delta front subfacies are mainly developed in the lower member of Kuqa formation in Ridarik area,and the ore bodies are located in the changing parts of sand body from thick to thin and argillaceous barrier layers being more and thicker.The epigenetic alteration zoning in the area is more obvious,and the ore belt is mostly in the front edge of gray-white belt among the strong clay alteration,which is not easy to identify.Through the statistics analysis of geochemical data,the identification marks of gray-white belt were established,which provide reference for the subsequent exploration of Neogene sandstone-type uranium deposits in Tarim basin.