鄂尔多斯盆地南部长7段深水沉积特征及沉积模式

发布时间：2018-12-14 20:01

【摘要】：鄂尔多斯盆地南部延长组深水沉积砂体的成因类型及沉积模式研究具有较大的争议,而且只用一种成因模式去解释深水沉积系统有一定的局限性。依据对鄂尔多斯盆地南部延长组长7段的野外剖面的观测及部分岩芯观察,基于沉积学相标志分析,对盆地延长组长7段深水沉积砂体特征及沉积模式进行了详细研究,取得了以下认识:首先,划分了研究区深水沉积砂体成因类型,包括风暴岩、滑动岩、滑塌岩、砂质碎屑流沉积及浊流沉积,总结了各类型深水沉积体的识别标志;其次,将研究区深水沉积体系划分为水道化的风暴沉积体系和无水道发育的滑移-滑塌沉积体系;风暴沉积体系划分为水道化风暴岩、水道侧缘及风暴浊积岩朵叶体,为风暴侵蚀成因;滑移-滑塌体系可以分为滑动岩、滑塌岩、碎屑流舌状体、远源浊流沉积,为地震、火山或风暴活动触发三角洲前缘坡折带沉积物失稳滑塌形成。综合砂体成因类型和沉积模式,可以更加直观地研究湖盆深水区沉积物组合及分布规律,为湖盆深水区油气勘探提供理论支撑。
[Abstract]:The genetic types and sedimentary models of deep-water sedimentary sandbodies in Yanchang formation in the southern Ordos Basin are controversial, and only one genetic model is used to explain the deep-water sedimentary system. Based on the observation of field profile and some core observations of member 7 of Yanchang formation in southern Ordos Basin, and based on the analysis of sedimentary facies markers, the characteristics and sedimentary model of deep-water sedimentary sand body of member 7 of Yanchang formation in Yanchang Basin are studied in detail. The main conclusions are as follows: firstly, the genetic types of deep-water sedimentary sandbodies in the study area are divided, including storm rocks, sliding rocks, sloughing rocks, sand clastic flow deposits and turbidite deposits, and the identification criteria of various types of deep-water sedimentary bodies are summarized. Secondly, the deep-water sedimentary system in the study area is divided into storm sedimentary system with waterway and slip-slide sedimentary system without waterway development. Storm sedimentary system is divided into watercourse storm rock, channel lateral edge and storm turbidite flower leaf body, which is the cause of storm erosion. The slip-slip system can be divided into sliding rock, sloughing rock, clastic flow tongue body, and distant turbidite deposition, which is caused by earthquakes, volcanoes or storms to trigger the unstable collapse of sediment in the delta front slope break zone. The combination of genetic types and sedimentary models of sand bodies can more intuitively study the assemblage and distribution of sediments in the deep water area of the lake basin and provide theoretical support for oil and gas exploration in the deep water area of the lake basin.
【作者单位】：中国地质大学(北京)能源学院;
【基金】：国家油气重大专项(2011ZX05009-002)资助
【分类号】：P618.13

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