鄂尔多斯盆地姬塬地区前侏罗纪古地貌沉积特征研究  

Study on sedimentary characteristics of pre-Jurassic paleogeomorphology in Jiyuan area,Ordos Basin

作　　者：马海勇[1,2] 韩天佑[3] 周磊 蔡玥 MA Haiyong;HAN Tianyou;ZHOU Lei;CAI Yue(College of Geology & Environment, Xi′an University of Science and Technology, Xi′an 710054, China;Department of Geology, Northwest University, Xi′an 710069, China;Research Institute of Petroleum Exploration and Development, Changqing Oilfield Company, Xi′an 710018, China;Shaanxi Binchang Mining Group Co., Ltd., Xianyang 712000, China)

机构地区：[1]西安科技大学地质与环境学院,陕西西安710054 [2]西北大学地质学系,陕西西安710069 [3]长庆油田分公司勘探开发研究院,陕西西安710018 [4]陕西彬长矿业集团有限公司,陕西咸阳712000

出　　处：《西北大学学报（自然科学版）》2021年第5期891-900,共10页Journal of Northwest University（Natural Science Edition）

基　　金：陕西省自然科学研究计划项目(2018JM4033)。

摘　　要：利用岩心观察、地震解释资料和地层厚度印模等方法对鄂尔多斯盆地姬塬地区前侏罗纪古地貌的沉积特征进行研究。研究表明,研究区前侏罗纪古河的沉积特征主要为河道充填沉积,在沉积过程中伴有对河谷的侵蚀下切作用。宁陕古河自研究区西北向东南穿流而过,河谷发育,展布长达120 km,主河道宽20~30 km。蒙陕古河流向自北向南,主河道宽10~20 km。姬塬高地东斜坡平均坡降9~11 m/km,其上沉积了厚度约80 m的中粗砂岩、细砂岩地层。姬塬高地南斜坡平均坡降5~7 m/km,斜坡前缘发育阶地。研究认为,研究区古地貌形态可划分为高地、斜坡带、古阶地、河谷区、河间丘等5种古地貌单元,包含姬塬高地、定边高地及安边高地等3个高地,蒙陕古河、宁陕古河等2个古河;姬塬高地南部、定边高地南部及安边高地西部发育古阶地,蒙陕古河、宁陕古河河谷两侧发育斜坡带,蒙陕古河河道内部发育河间丘。Based on core observation,seismic interpretation data and impression of stratigraphic thickness,the sedimentary characteristics of pre-Jurassic paleogeomorphology have been studied in Jiyuan area.The research shows that the sedimentary characteristics of the pre-Jurassic ancient river are mainly formed by channel filling deposition,accompanied by erosion and cutting of the valley.The Ningshan ancient river runs through the study area from northwest to southeast,with a valley spread of 120 km and a main channel about 20~30 km wide.The Mengshan ancient river flows from north to south,the main channel is 10~20 km wide.The average slope of the east slope of Jiyuan plateau is 9~11 m/km,and there are medium coarse sandstone and fine sandstone strata with a thickness of about 80m deposited on it.The average slope of the south slope of Jiyuan plateau is 5~7 m/km,and terraces are developed at the front of the slope.It also shows that the paleogeomorphology in Jiyuan area can be divided into five paleogeomorphology units:highland,slope zone,paleogeomorphology,valley area and interfluvial mound.The paleogeomorphology in the pre-Jurassic includes three highlands:Jiyuan highland,Dingbian highland and Anbian highland.Mengshaan ancient river,Ningshaan ancient river and other two ancient rivers.Ancient terraces were developed in the south of Jiyuan plateau,the south of Dingbian plateau and the west of Anbian plateau.Slope zones were developed on both sides of the valleys of Mengshaan ancient river and Ningshaan ancient river,and interriver mounds were developed in the river channels of Mengshaan ancient river.It includes three plateaus,namely Jiyuan,Dingbian and Anbian.There are two ancient rivers,Mengshan ancient river and Ningshan ancient river.Ancient terraces were developed in the south of Jiyuan plateau,the south of Dingbian plateau and the west of Anbian plateau.Slope zones were developed on both sides of the valleys of Mengshan ancient river and Ningshan ancient river,and interriver mounds were developed in the river chan

关 键 词：鄂尔多斯盆地 姬塬地区 前侏罗纪 古地貌 沉积特征 

分 类 号：P512.2[天文地球—地质学]