柴达木盆地七个泉背斜狮子沟组与七个泉组构造-沉积演化及对砂岩型铀矿成矿的启示  

Tectonic-sedimentary evolution of the Shizigou and Qigequan Formations in Qigequan Anticline in Qaidam Basin:implications for the mineralization of sandstone-type uranium deposits

作　　者：施源 刘卫红[2] 邱隆伟[1] 高雪峰 董道涛 王宇喆 SHI Yuan;LIU Weihong;QIU Longwei;GAO Xuefeng;DONG Daotao;WANG Yuzhe(School of Geosciences,China University of Petroleum(East China),Shandong Qingdao 266580,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;Exploration Enterprise Department of Qinghai Oilfield Company,PetroChina,Qinghai Dunhuang 736202,China;Sanya Offshore Oil&Gas Research Institute,Northeast Petroleum University,Hainan Sanya 572025,China;Exploration and Development Research Institute of Daqing Oilfield Company,PetroChina,Heilongjiang Daqing 163712,China)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [2]中国石油天然气股份有限公司勘探开发研究院,北京100083 [3]中国石油青海油田分公司勘探事业部,甘肃敦煌736202 [4]东北石油大学三亚海洋油气研究院,海南三亚572025 [5]中国石油大庆油田勘探开发研究院,黑龙江大庆163712

出　　处：《古地理学报》2024年第3期700-713,共14页Journal of Palaeogeography：Chinese Edition

基　　金：国家自然科学基金项目(编号:42172115)资助。

摘　　要：从构造-沉积演化角度分析矿体的形成和发育过程是砂岩型铀矿研究工作的重要内容。作者基于文献调研、野外地质调查和井震解释,对柴达木盆地七个泉背斜狮子沟组与七个泉组构造-沉积演化过程及其与砂岩型铀矿成矿的联系开展研究。研究认为:(1)狮子沟组富泥质砂,呈现退积旋回;七个泉组富砾,呈现进积旋回,底部与狮子沟组间发育新近系—第四系角度不整合,内部发育规模稍小的第四系内部角度不整合;狮子沟组—七个泉组发育由泥石流、下切沟道—充填和片流沉积构成的大型冲积扇,其中砂质层中密集发育地震变形构造。(2)新近纪以来最剧烈的构造抬剥事件发生在新近纪—第四纪之交,由此形成了新近系—第四系不整合并奠定了七个泉背斜构造格局。(3)推测七个泉背斜狮子沟组砂岩型铀矿潜在铀矿化段主要形成于新近纪—第四纪构造抬剥事件中,该事件催生出含矿构造,并加大了源区铀通量,最终控制了潜在铀矿化段形成发育和空间展布。新近系—第四系不整合则可作为预测潜在铀矿化段空间展布的关键构造控矿标志。同时,冲积扇扇中/扇缘中砂砾岩百分含量介于20%~50%之间的砂(砾)泥互层带可作为关键沉积控矿标志。研究成果可以为青藏高原东北缘盆地分析提供沉积学和地层学证据,对理解柴达木盆地其他背斜砂岩型铀矿形成发育过程具有重要价值。It is of great significance for understanding the initiation and evolution of sandstone-type uranium deposits from the perspective of tectono-sedimentary evolution.In this study,based on a literature review,fieldwork,logging and seismic data,the tectono-sedimentary evolution of the Shizigou and Qigequan Formations in Qigequan Anticline in the Qaidam Basin and its links to the mineralization of sandstone-type uranium deposits are revealed.Our findings indicate that:(1)The Shizigou Formation is characterized by argillaceous-sandstone-rich stratum associated with retrogradation,while the Qigequan Formation is characterized by conglomerate-rich stratum associated with progradation.The Neogene-Quaternary angular unconformity developed between the Shizigou and Qigequan Formations and the Intra-Quaternary angular unconformity developed inside the Qigequan Formation.Large-scale alluvial fans,composed of debris flow,incised-valley-fill,and sheet flow deposits,were developed in the Shizigou and Qigequan Formations,and the sandy earthquake-induced soft-sediment deformation layers were frequently developed in the Shizigou and Qigequan Formations.(2)The most intensive uplift and denudation events occurred between the Neogene and the Quaternary,resulting in the initiation of the Neogene-Quaternary angular unconformity and the tectonic setting of the Qigequan Anticline.(3)It can be inferred that these potential uranium mineralization columns of the Shizigou Formation in the Qigequan Anticline developed in the uplift and denudation events between the Neogene and the Quaternary.The uplift and denudation events led to the initiation and evolution of the uranium-bearing structure,and increased the uranium flux from the source area and dominated the spatial distribution of the potential uranium mineralization columns ultimately.The Neogene-Quaternary angular unconformity can be used for the spatial distribution predicting of the potential uranium mineralization columns as a key tectonic identification mark.In addition,the thin inter

关 键 词：柴达木盆地 新近系— 第四系 七个泉背斜 构造-沉积演化 砂岩型铀矿 

分 类 号：P619.14[天文地球—矿床学]