鄂尔多斯盆地东南缘中元古代盆地属性分析

Attribute Analysis of Mesoproterozoic Basins in Southeastern Margin of Ordos Basin

研究区位于华北地台鄂尔多斯地区东南部,主要包括洛南县巡检镇地区。在前人研究和野外露头资料的基础上,系统分析研究区中元古代不同时期的构造沉积特征,对鄂尔多斯盆地东南缘中元古代时期有了较为全面而系统的认识。研究发现:(1)鄂尔多斯盆地东南缘中元古代为一裂谷盆地,其层序在纵向上存在断拗双层结构;(2)该地区中元古代熊耳期为一裂谷盆地,长城纪和蓟县纪变为裂谷后凹陷环境,先后发育了潮坪-河口砂坝相高山河群、汝阳群沉积和洛南群白云岩沉积。

Study area is located in the southern margin of the North China, including Luonan County Xunjian town area. On the basis of predecessors＇ research and field outcrop data, sedimentary characteristics of Mesoproterozoic different structural parts constructed in different periods were analyzed to have a more comprehensive and systematic understanding for southeastern margin of Ordos basin during the Mesoproterozoic. The results show that, the southeastern margin of Ordos basin was a rift basin during the Mesoproterozoic, its sequence had bilayer structure in the longitudinal direction; The area during the Mesoproterozoic Xiong＇er was a rift basin, and then it changed into rift sag environment during the Changchengian period and Jixianian period, and developed into the Tidal flat- mouth bar phase Gaoshanhe group, Ruyang group deposition and Luonan group dolomite deposition.