鄂尔多斯盆地旬邑地区长7_1段重力流沉积特征及其模式  

Sedimentary Characteristics and Model of Gravity Flow in Chang 7_1 Member of Xunyi Area,Ordos Basin

作　　者：王振[1] 张元福[1,2] 汤望新[1,2] 白一鸣[1] 张博文[1] 魏康强 

机构地区：[1]中国地质大学(北京)能源学院 [2]中国地质大学(北京)科学研究院,北京100083

出　　处：《科学技术与工程》2016年第22期20-27,共8页Science Technology and Engineering

基　　金：国家"十二五"科技重大专项(2011ZX05009-002)资助

摘　　要：通过对野外露头剖面进行详细的观察、描述、测量、采样,并结合岩石镜下特征,对鄂尔多斯盆地旬邑地区延长组长7_1段出露的沉积类型和沉积特征进行系统研究。发现研究区广泛发育重力流沉积,类型主要为砂质碎屑流沉积和浊流沉积,岩性以岩屑长石砂岩和长石岩屑砂岩为主。砂质碎屑流砂体显示块状构造为典型特征,同时发育各种类型的底模及软沉积构造,单层砂体厚度多在0.5 m以上。浊流沉积砂体发育粒度递变层理和鲍玛序列为典型特征,浊流沉积砂体单层厚度多在0.5 m以下。横向上砂体表现为"底平顶凸"的透镜状分布特征,垂向上砂质碎屑流砂体、浊流沉积砂体和深湖相泥岩3种沉积体相互叠置,构成有利的油气生、储条件;综合研究区各种相关地质资料对该区重力流沉积形成机制进行探讨,认为季节性洪水和古地震活动为该区重力流沉积的诱发因素。According to the detailed observation, description, measurment, sampling of the iield section out- crops and combined with the microscopic characteristics of rock to systematic research sedimentaff types and sedi- mentary characteristics of Chang71 Member in Xunyi area, Ordos Basin, the gravity flow deposition types of the area are mainly sandy debris flow and turbidity current. There are mainly lithic arkose and feldspathic lithic sandstone. The sandy debris flow develops typical massive structure and other sedimentary structures, the thickness of sandy debris flow sand is usually more than 0. 5 m. The turbidite is characterized by developing graded bedding and Bao- ma sequence and the turbidity current sand is usually below 0. 5 m. The sand body is manifested as the bottom fiat convex lens shape distribution characteristics in horizontal and the sandy debris flow, turbidity current, deep lacus- trine mud three microfacies superimposed each other in vertical to constitute a favorable petroleum reservoir and generation conditions. Comprehensive relevant geological data area to discuss the formation mechanism of gravity flow deposition and think seasonal floods and ancient earthquake activity are inducing factors of gravity flow deposits in the region.

关 键 词：鄂尔多斯盆地 长71段 重力流 沉积特征 沉积模式 

分 类 号：P548[天文地球—构造地质学]