二连盆地马尼特坳陷南缘赛汉塔拉组砂岩碎屑锆石年龄及其地质意义  

Geochronology and Geological Significance of Sandstone Detrital Zircons from Saihantala Formation in Southern Manite Depression,Erlian Basin

作　　者：俞礽安 吴兆剑[3,4] 司马献章 韩效忠[3] 李紫楠 文思博[1,2] 涂家润 Yu Reng'an;Wu Zhaojian;Sima Xianzhang;Han Xiaozhong;Li Zinan;Wen Sibo;Tu Jiarun(Tianjin Geological Survey Center of China Geological Survey,Tianjin 300170,China;Key Laboralory of Uranium Geology,China Geological Suervey,Tianjin 300170,China;Branch Company of Geological Survey,China Coal Geology Group Company Limited,Beijing 100040,China;School of the Earh Sciences and Resoures,China Untversily of Geosciences,Bejjing 10088,China)

机构地区：[1]中国地质调查局天津地质调查中心,天津300170 [2]中国地质调查局天津地质调查中心铀矿地质重点实验室,天津300170 [3]中煤地质集团有限公司北京地质调查分公司,北京100040 [4]中国地质大学地球科学与资源学院,北京100083

出　　处：《地球科学》2020年第5期1609-1621,共13页Earth Science

基　　金：中国地质调查局项目(No.DD20190119);国家重点研发计划项目(No.2018YFC0604200);国家重点基础研究计划973项目(No.2015CB453000);中国煤炭地质总局科技项目(No.ZMKJ-2018-18)。

摘　　要：二连盆地是我国重要的产煤炭、石油、铀资源的能源矿产基地之一.综合以往资料可知,二连盆地煤和铀矿均主要赋存于下白垩统赛汉塔拉组,但受盆地构造演化的制约,煤矿在盆地东部地区较为发育,在盆地中西部规模变小、厚度减薄;而铀矿的分布规律则相反.为进一步了解构造-沉积演化对煤、铀成矿过程和赋矿机理的约束,选取马尼特坳陷南缘恩格日音地区赛汉塔拉组下段砂岩开展地球化学和碎屑锆石U-Pb测年研究,探索其物源变化规律;同时对比分析马尼特坳陷东段和西段地震剖面,约束关键构造时限.结果显示:(1)马尼特坳陷南缘赛汉塔拉组下段下亚段物源以坳陷北缘的巴音宝力格隆起为主,而下段上亚段物源以坳陷南缘的苏尼特隆起为主,指示苏尼特隆起在早赛汉塔拉期晚期发生较强烈隆升;(2)马尼特坳陷南缘赛汉塔拉中期,沉积水体较浅,不利于煤的沉积;(3)苏尼特隆起构造隆升可能为坳陷南缘赛汉塔拉组下段铀成矿提供条件.这对了解二连盆地煤、铀的空间配置,预测马尼特坳陷、乌兰察布坳陷南缘新区新层位铀成矿具有较为重要的理论意义.Erlian basin is one of the most important energy mineral bases bearing coal,oil and uranium.Although both of coal and uranium deposits mainly occur in lower Cretaceous Saihantala Formation,previous data reveal that most of coal mines are distributed in the eastern Erlian basin;while major uranium deposits are found in the midwestern Erlian basin.In order to understand the tectono-sedimentary evolution progress and its constraints on mineralization of coal and uranium,we took Saihantala Formation sandstones in Engeriyin area of southern Manite depression for geochemical and detrital zircons geochronological analysis.Combined with previous seismic data in eastern and western Manite depression,we conclude that(1)the lower and upper subinterval of the lower Saihantala Formation in southern Manite depression have different provenances,and the lower subinterval is composed of terrigenous materials from Bayinbaolige rise,while the upper subinterval from Sunite rise,which may indicate the Sunite rise began to uplift in the late substage of the Early Saihantala period;(2)the water depth became shallow in Southern Manite depression during the middle period of Saihantala and it counted against the formation of coal;(3)the uplift of Sunite rise might provide beneficial tectonic condition for uranium mineralization in the lower Saihantala Formation in southern Manite depression.This is significant for us to understand the space allocation of coal and uranium in Erlian basin and evaluate the uranium metallogenic prospects in southern Manite depression.

关 键 词：碎屑锆石U-PB年龄 铀成矿 赛汉塔拉组 马尼特坳陷 二连盆地 矿产地质 

分 类 号：P597[天文地球—地球化学]