中国北方砂岩型铀矿中铀的储集空间类型探讨

An approach to the uranium reservoir space types in the sandstone-type uranium deposits in northern China

摘要: 在中国北方的大多数沉积盆地里均发现有砂岩型铀矿床或铀矿化现象。通过样品薄片电子探针背散射图像分析,结合前人对各盆地砂岩型铀矿中铀矿物的赋存状态及近年来铀储层的研究成果,认为中国北方砂岩型铀矿中铀矿物的主要储集空间类型可分为原生孔隙(主要是炭屑)、缩小(残留)粒间孔隙、次生溶蚀孔隙、晶间孔隙及微裂缝。通过对铀储层孔隙类型的分析讨论,有利于进一步从微观了解砂岩铀储层内部结构的不均一性及铀矿物的成因。

Abstract: The sandstone-type uranium deposits or uranium mineralization were discovered in most of sedimentary basins in northern China. The authors propose, in terms of backscattered electron images analysis in this study and previous results of research concerning the uranium occurrence and uranium reservoirs in the sandstone-type uranium deposits in some sedimentary basins in northern China that the main reservoir space types in the sandstonetype uranium deposits in northern China include the primary pores (dominatedly charcoal debris), narrow or residual intergranular pores, secondary dissolution pores, intercrystal pores and microfissures. The diagenesis and postdiagenetic alteration may change the pore structures and types, and facilitate the reduction and precipitation of uranium.