东胜直罗组砂岩成岩作用过程与古流体运移事件分析  

Diagenesis and Palaeo-fluid Migration Events in the Zhiluo Formation in Dongsheng Area

作　　者：樊爱萍[1] 柳益群[1] 杨仁超[2] 张复新[1] 

机构地区：[1]西北大学地质学系,西安710069 [2]山东科技大学地质工程系,青岛266510

出　　处：《地质学报》2006年第5期694-699,i0001,共7页Acta Geologica Sinica

基　　金：国家重点基础研究发展计划"973"项目(编号2003CB214603);长江学者和创新团队发展计划(编号IRT0559)资助的成果。

摘　　要：通过分析岩矿薄片、流体包裹体、扫描电镜和阴极发光的测试结果,认为东胜地区直罗组经历了较复杂的成岩作用过程,成岩作用对砂岩物性影响较大。砂岩中低温热液矿物组合证明了古流体事件的存在。古流体以流体包裹体的形式在胶结物中得以保存。研究同时表明,直罗组砂岩中共发生过三幕古流体运移事件。其中第一、二幕记录于硅质胶结物中,主要为有机热流体事件,烃类与盐水包裹体共存,均一温度分别为89℃和124℃。第三幕主要记录于碳酸盐胶结物中,主要为无机热流体事件,只发育盐水包裹体,均一温度为163℃。强烈的胶结作用及多幕古流体事件的存在说明东胜地区直罗组砂岩中古流体活动频繁,有利于富铀流体在其中迁移和铀矿的沉淀、富集。Characteristics of diagenetic evolution of sandstone in the Zhiluo Formation in Dongsheng area was studied with microscope, scaning electron microscopy, electron probing, cathodoluminescence technology and fluid inclusions data. Diagenesis imposed the effect on the sandstone. The low-temprature thermal fluid minerals association turned out the existence of thermal fluid. Paleo-thermal fluid was preserved in cements in terms of fluid inclusions The research also shows that three episodes of palaeo-thermal fluid migration events took place in the sandstone. The first and second episodes recorded in the siliceous cements were featured by a few of inclusions, which included.aqueous and hydrocarbon inclusions, the homogeneous temperatures of 89℃ and 124℃. The third episode, mainly an inorganic low-temperature thermal fluid event, was characterized by the aqueous fluid inclusions in the carbonate cements, and the homogeneous temperatures of 163℃. The violent cementation and multi-episode thermal fluids events showed that paleo-thermal fluid events take place frequently in sandstone of Zhiluo formation, which are available to migration of metallogenic fluid, deposition and assemblage of uranium.

关 键 词：直罗组 成岩作用 流体包裹体 

分 类 号：P619.14[天文地球—矿床学]