鄂尔多斯盆地南缘岐山曹家沟奥陶系剖面地层和沉积特征  

Ordovician stratigraphy and sedimentary characteristics of Caojiagou section in Qishan County,southern margin of Ordos Basin

作　　者：陈强[1] 李文厚[2] 孙娇鹏 张倩[2] 梁积伟[1] 李智超[3] CHEN Qiang;LI Wenhou;SUN Jiaopeng;ZHANG Qian;LIANG Jiwei;LI Zhichao(School of Earth Science and Resources,Chang’an University,Xi’an,Shaanxi 710054,China;Department of Geology,Northwest University,Xi’an,Shaanxi 710069,China;School of Land Engineering,Chang’an University,Xi’an,Shaanxi 710054,China)

机构地区：[1]长安大学地球科学与资源学院,陕西西安710054 [2]西北大学地质学系,陕西西安710069 [3]长安大学土地工程学院,陕西西安710054

出　　处：《油气藏评价与开发》2022年第1期246-254,264,共10页Petroleum Reservoir Evaluation and Development

基　　金：陕西省自然科学基础研究计划项目“鄂尔多斯西南缘奥陶系碳酸盐重力流成因机制及构造古地理意义”(2021JM-158);国家科技重大专项“鄂尔多斯盆地南部早古生代岩相古地理、构造演化与天然气富集关系研究”(2011ZX05005-004-07HZ);中央高校基本科研业务费资助项目“鄂尔多斯西南缘早古生代重力流沉积及其对秦岭洋俯冲的响应”(0009-2014G1271062)。

摘　　要：陕西岐山曹家沟剖面位于鄂尔多斯盆地南缘,交通便利、出露良好、地层齐全、沉积类型多样,是一条重要的奥陶系剖面。对曹家沟剖面进行了详细介绍,下奥陶统冶里组以泥质白云岩为主,亮甲山组以含硅质团块晶粒白云岩为特征,发育叠层石,均为潮坪相沉积。中奥陶统马家沟组主要为中薄层—中厚层的粉细晶云岩、灰岩,属开阔台地—台地前缘斜坡相沉积,峰峰组主要为中薄层—纹层状白云岩,发育大量薄层的碳酸盐碎屑流和浊流沉积,属较深水的台地前缘斜坡相重力流沉积。上奥陶统平凉组为一套大陆斜坡相类复理石的韵律沉积,唐王陵组为大陆斜坡相泥石流环境下的冰水沉积,具有典型的冰坠石构造。The Caojiagou section in Qishan County,Shaanxi Province is located in the southern margin of the Ordos Basin.The well-exposed section deposited complete Ordovician strata and developed various sedimentary types,and its location has convenient transportation.In this paper,the stratigraphy and sedimentary characteristics of the Caojiagou section are introduced in detail.The lower Ordovician Yeli Formation is mainly composed of argillaceous dolomite and Mount Liangjia Formation is characterized by crystal dolomite intercalated with siliceous mass and develops stromatolites,all of which belong to tidal flat facies.The Middle Ordovician Majiagou Formation consists of medium-thin and medium-thick layers of silty-fine dolomite and limestone,belonging to open platform and platform front slope facies deposits.The Fengfeng Formation is mainly composed of medium-thin layer laminated dolomite with a great quantity of thin carbonate debris flow and turbidity current deposits,which represent the gravity flow deposit of the front slope of the platform in the deep-water environment.The Upper Ordovician Pingliang Formation mainly consists of a set of flyschoid rhythmic deposits of the continental slope facies.The Tangwangling Formation represents the debris flow environment of the continental slop and develops the ice-water deposits with typical ice-rafted dropstones.

关 键 词：地层特征 深水沉积 冰川沉积 奥陶系 曹家沟剖面 鄂尔多斯盆地 

分 类 号：TE121[石油与天然气工程—油气勘探]