库车坳陷中-新生代构造-流体演化与铀成矿关系  

Meso-Cenozoic tectonic and fluid evolution and uranium mineralization in the Kuqa depression

作　　者：刘念 秦明宽 郭强[1,2,3] 许强 王强强[4] 肖菁 张浩[1,2,3] LIU Nian;QIN Mingkuan;GUO Qiang;XU Qiang;WANGQiangqiang;XIAO Jing;ZHANG Hao(National Key Laboratory of Uranium Resources Exploration-Mining and Nuclear Remote Sensing,Beijing 100029,China;Beijing Research Institute of Uranium Geology,Beijing 100029,China;CNNC Key Laboratory of Uranium Resources Exploration and Evaluation Technology,Beijing 100029,China;Geologic Party No.216,CNNC,Urumqi 830011,China)

机构地区：[1]铀资源探采与核遥感全国重点实验室,北京100029 [2]核工业北京地质研究院,北京100029 [3]中核集团铀资源勘查与评价技术重点实验室,北京100029 [4]核工业二一六大队,新疆乌鲁木齐830011

出　　处：《世界核地质科学》2024年第5期857-874,共18页World Nuclear Geoscience

基　　金：核技术研发科研项目(编号:地HTLM2101)资助。

摘　　要：在剖析系列剖面的构造变形特征基础上,采用盆地建模方法构建中-新生代各层的构造形态;利用磷灰石裂变径迹、磷灰石(U-Th)/He以及平衡剖面恢复等技术精细恢复库车坳陷中-新生代构造演化过程;在此基础上,采用盆地模拟法模拟重点层位的流体演化过程并探讨构造-流体演化与砂岩型铀成矿的关系。结果表明:库车坳陷构造变形强度表现为“西强东弱”的特征,中-新生代存在晚侏罗世-早白垩世、古近纪-中新世和上新世-第四纪三期构造隆升事件,分别是拉萨地体与欧亚板块碰撞拼贴、Kohistan-Dras岛弧增生以及印度板块与欧亚板块递进式碰撞造成的。库车坳陷新近系油气逸散现象明显,主要沿克拉苏、依奇克里克以及秋里塔格构造带分布,油气主要来源于深部三叠系-侏罗系烃源岩,存在23~5 Ma和5 Ma至今两期油气逸散过程。库车坳陷库车组的含氧含铀水主要由南天山供给,部分由秋里塔格构造带补给。渗出流体从拜城凹陷以“汇聚流+面流”的方式运移至直线褶皱带,向南以“面流”的方式运移至秋里塔格构造带,并在隆起区汇聚。中-新生代构造-流体演化控制库车坳陷砂岩型铀成矿作用,总体表现为“早期层间氧化-晚期渗出接力成矿”的特征。In this paper,the basin modeling method was used to construct the structural morphology of the Mesozoic and Cenozoic layers in Kuqa depression of Tarim basin by analysis of the structural deformation characteristics of a series of sections.A comprehensive investigation on the Meso-Cenozoic tectonic evolution of the Kuqa depression was conducted using apatite fission track,apatite(U-Th)/He,and balanced cross-section methods,the fluid evolution process of key layers was simulated,the relationship between the Meso-Cenozoic tectonic and fluid evolution of the Kuqa depression and sandstone-type uranium mineralization was discussed.The results show that the structural deformation strength of Kuqa depression is characterized as“strong in the west and weak in the east”.The study area experienced three important cooling events during the Late Jurassic-Early Cretaceous,Paleogene to Miocene and Pliocene to Quaternary,which were caused by the collage of Lhasa terrane and Eurasian plate,Kohistan-Dras island arc accretion,and progressive collision between the Indian and Eurasian plate,respectively.Oil and gas leakage phenomenon is obvious in the Neogene of Kuqa depression,mainly distributed along the Kelasu,Yiqikelike and Qiulitage structural belts.The hydrocarbon is mainly derived from deep Triassic and Jurassic source rocks,and there are two stages of hydrocarbon leakage from 23 Ma to 5 Ma and from 5 Ma to present.The oxygenated uranium containing water in Kuqa depression is mainly supplied by the South Tianshan Mountain,and partly by Qiulitage structural belt.The seepage fluid migrated from the Baicheng depression to the Linear fold belt in the form of“convergent flow and surface flow”,and migrated southward to Qiulitage structural belt in the form of“surface flow”,and pooled in the Uplift belt.The tectonic and fluid evolution controlled the sandstone uranium mineralization in the Kuqa depression,showing the characteristics of“early interlayer oxidation and late exudation relay mineralization”.

关 键 词：构造演化 古流体 油气还原 砂岩型铀矿 库车坳陷 

分 类 号：P598[天文地球—地球化学] P619.14[天文地球—地质学]