新疆乌拉根铅锌矿克五段扇三角洲沉积模式

下白垩统克孜勒苏群五段（K₁kz5）为塔里木盆地喀什凹陷北部乌拉根铅锌矿主要含矿层位。以研究区野外实测地层-沉积剖面为基础，根据克孜勒苏群第五岩性段岩石学、沉积构造及薄片粒度分析，确定了研究区克孜勒苏群五段的沉积模式。结果表明:研究区克孜勒苏群第五岩性段地层自乌拉根古隆起向北发育了一套完整的扇三角洲沉积相，并可进一步划分为水上、水下两部分，分别为水上部分-扇三角洲平原的分流河道、分流河道间；水下部分-扇三角洲前缘水下分流河道、河口坝、远砂坝、分流间湾和前扇三角洲。通过沉积相与矿体位置关系的研究表明，铅锌矿体主要赋存于扇三角洲平原和扇三角洲前缘过渡地带的（水下）分流河道微相的细粒砂砾岩和中-细粒砂岩中。扇三角洲沉积模式与铅锌成矿关系密切，它不仅促进了原始矿源层的形成，还为后期改造成矿提供了场所。

Sedimentary Model of Fan Delta in the Fifth Member of Kizilsu Group in Uragen Pb-Zn Deposit,Xinjiang

The fifth member of the Lower Cretaceous Kizilsu Group is the main ore-bearing horizon in the Uragen Pb-Zn deposit in the northern Kashi Sag, Tarim Basin. A sedimentary model was constructed of the petrology, sedimentary structure and grading analysis of the fifth member of Kizilsu Group, based on a survey of a stratigraphic-sedimentary section in this area. This showed that the full fan delta facies was developed following the Uragen uplift of the fifth member of Kizilsu Group in the study area, and may be divided into subfacies including a fan delta plain, a fan delta front and a front fan delta. The microfacies of the distributary channel, underwater distributary channel, distributary bend, estuarine dam and far sand dam were also further divided. It was found that the main ore bodies occur in the (underwater) distributary channel microfacies of the fan delta plain and in the front transition zone of the fan delta. The fan delta sedimentary model is closely related to lead-zinc mineralization, since it promoted the formation of the original source bed and provided a location for later re-formation and ore-forming.