鄂尔多斯盆地南部彬长地区直罗组后生蚀变特征研究  

Epigenetic Alteration Characteristics of Zhiluo Formation in Binchang Area,Southern Ordos Basin

作　　者：冯博 王晓鹏 武正乾 王凯 聂利 刘凯鹏 周伟 FENG Bo;WANG Xiaopeng;WU Zhengqian;WANG Kai;NIE Li;LIU Kaipeng;ZHOU Wei(Research Institute No.203,CNNC,Xi’an,Shaanxi 710086,China)

机构地区：[1]核工业二〇三研究所,陕西西安710086

出　　处：《铀矿地质》2023年第6期970-978,共9页Uranium Geology

基　　金：中国核工业地勘基金项目“鄂尔多斯盆地南部旬邑-盐池地区铀矿资源评价与勘查”(编号:2022-17);中核集团集中研发项目“砂岩型铀矿多重耦合地质成矿作用与时空定位”(编号:中核科发2021-143号)联合资助。

摘　　要：通过对鄂尔多斯盆地彬长地区直罗组后生蚀变特征进行系统研究,认为彬长地区中侏罗统直罗组存在早期紫红色氧化蚀变和晚期灰白色、灰绿色还原褪色蚀变两种蚀变类型。早期氧化蚀变的主要蚀变矿物为微粒状褐铁矿和褐铁矿集合体,而晚期灰白色、灰绿色褪色还原蚀变的蚀变矿物主要为黄铁矿、绿泥石以及部分残留未完全氧化的炭屑。研究区直罗组蚀变在垂向上分带明显,在垂向上铀矿化主要受灰绿色褪色蚀变砂体与原生灰色砂体的过渡部位控制,铀矿物主要为铀石,常分布于炭屑中且与黄铁矿伴(共)生;平面上,铀矿化产于氧化—还原过渡带内。Based on the systematic study of epigenetic alteration characteristics of Zhiluo formation in Binchang area,Ordos basin,it was concluded that there were two types alteration in the Middle Jurassic Zhiluo formation:early purplish red oxidation alteration and late grayish white and grayish green reduction fading alteration.The main alteration minerals of early oxidation alteration are granular limonite and limonite aggregate,while the alteration minerals of late grayish white and grayish green fading reduction alteration are mainly pyrite and chlorite,and some residual incomplete oxidized carbon chips.The alteration of Zhiluo formation in the study area is obvious in the vertical zonation,and uranium mineralization in the vertical is mainly controlled by the transition position of uranium mineralization,grayish-green fading alteration and primary sand body.Uranium minerals are mainly uranite,which is often distributed in the carbon dust and occurs(accompanied and co-existed)with pyrite.On the plane,uranium mineralization occurs in the oxidation-reduction transition zone.

关 键 词：直罗组 蚀变特征 铀矿化 彬长地区 

分 类 号：P619.14[天文地球—矿床学]