鄂尔多斯盆地南部石盒子组盒8下段砂岩物源分析  

Provenance Analysis of Sandstone in Lower Segment of He 8 Memberof Shihezi Formation,Southern Ordos Basin

作　　者：马尚伟 魏丽 赵飞 尹小龙[3] 陈红锦 MA Shangwei;WEI Li;ZHAO Fei;YIN Xiaolong;CHEN Hongjin(Xi’an Geological Survey Center,China Geological Survey,Xi’an,Shaanxi 710054,China;Shaanxi Geological Survey and Planning Research Center(Shaanxi Geological Exploration Fund Center),Xi’an,Shaanxi 710068,China;The First Gas Production Plant,PetroChina Changqing Oilfield Company,Jingbian,Shaanxi 718500,China;School of Earth Resources,China University of Geosciences(Wuhan),Wuhan,Hubei 430000,China)

机构地区：[1]中国地质调查局西安地质调查中心,陕西西安710054 [2]陕西省地质调查规划研究中心(陕西省地质勘查基金中心),陕西西安710068 [3]中国石油长庆油田分公司第一采气厂,陕西靖边718500 [4]中国地质大学(武汉)资源学院,湖北武汉430000

出　　处：《西安石油大学学报（自然科学版）》2023年第4期1-11,共11页Journal of Xi’an Shiyou University（Natural Science Edition）

基　　金：中国地质调查局项目“西北含油气盆地油气战略性矿产调查评价”(DD20230314)、“氦气资源调查评价与示范”(DD20230026)、“全国氦气资源潜力评价”(DD20221665)和“汾渭盆地氦气资源勘查示范”(DD20230268)共同资助。

摘　　要：通过岩石薄片鉴定、轻矿物、重矿物、主/微量元素和锆石U-Pb定年等方法,综合分析鄂尔多斯盆地南部盒8下段物源方向及来源。结果表明,研究区盒8下段储层岩性主要以岩屑砂岩和岩屑质石英砂岩为主,岩屑以变质岩岩屑和岩浆岩岩屑为主。综合古流向、长石含量分布、重矿物组合特征及判别指标等研究表明,研究区盒8下段主要存在4个大方向的物源区,分别为西南部、东南部、中南部和中北部。南部3个物源方向均有相似的物质来源,主要来自华北古老基底再旋回物质,其次来自北秦岭造山—北祁连造山带源区。西南部存在2个物源区,Ⅰ区存在少量可能来自北秦岭—北祁连造山带结合部位的陇山杂岩的物源,Ⅱ区为南北物源汇聚区,存在少量可能来自陇山杂岩的物源,阴山地块也可能为该区提供物源供给。The provenance directions and sources of the lower segment of He 8 member in the southern Ordos Basin were comprehensively analyzed by means of thin section identification,light mineral,heavy mineral,major and trace element analysis and zircon U-Pb dating.The results show that the lithology of the lower segment of He 8 member in the study area is mainly lithic sandstone and lithic quartz sandstone,and lithic debris is mainly metamorphic rock and magmatic rock.The study on paleocurrent direction,feldspar content distribution,heavy mineral assemblage characteristics and discriminant indexes show that the provenance of the lower segment of He 8 member in the study area mainly comes from four directions,namely,southwest,southeast,south-central and north-central.The three provenance directions in the south all have similar material sources,mainly from the cyclic material of ancient basement in North China,followed by the source region of the North Qinling orogenic belt and North Qilian orogenic belt.In particular,there are two provenance regions in the southwest:Ⅰregion,there is a small amount of Longshan diamictite,coming from the junction of the North Qinling orogenic belt and North Qilian orogenic belt;Ⅱregion,is a convergence area of provenance from north and south,where there is a small amount of Longshan diamictite.Yinshan block may also provide material supply forⅡregion.

关 键 词：物源分析 轻矿物 重矿物 盒8下段 鄂尔多斯盆地南部 

分 类 号：TE122.2[石油与天然气工程—油气勘探]