地质科学2017，Vol.52Issue(3)：931-942,12.DOI:10.12017/dzkx.2017.058
鄂尔多斯盆地西南缘岐山地区中奥陶统沉积特征及沉积环境研究
A study on the Middle Ordovician sedimentary characteristics and environment of Qishan region at the southwest margin of Ordos Basin
摘要
Abstract
Through the feild sections measurement,sample selection and thin section analysis and the selection of geochemical data and previous research matetials,this paper studies the lithology composition and sedimentary structure in Qishan area and analyzes the evolution of sedimentary environment in Middle Ordovician.The results show that in Middle Ordovician Qishan area was in limited sea platform environment with deposition of dolomite at early stage of Lower Majiagou Formation and was in open sea platform environment with midium thich limestone depositing at the middle-late stage of Lower Majiagou Formation.In Upper Majiagou Formation,the area developed deposits of thick lamellar limestone interbedded with deep-water sedimentary construction like debris flow and turbidity flow which indicated platform foreslop enviroment and then in Fengfeng Formation,Qishan was still in platform foreslop enviroment but closer to deep water basin and developed thick lamellar limestone.With such envelops,it can be concluded that in Middle Ordovician,besides Chunhua-Xunyi depression Qishan region should be in another secondary depression with deeper water and steeper slope on southern depression.关键词
地层特征/岩性/沉积构造/重力流/地球化学/沉积环境/中奥陶统/岐山地区Key words
Stratigraphic features/Lithology/Sedimentary structures/Gravity flow/Geochemistry/Sedimentary environment/Middle Ordovician/Qishan region分类
天文与地球科学引用本文复制引用
刘溪,任战利,李文厚,陈强,贾德生..鄂尔多斯盆地西南缘岐山地区中奥陶统沉积特征及沉积环境研究[J].地质科学,2017,52(3):931-942,12.基金项目
国家自然科学重点基金项目(编号:41330315)和中央高校基本科研业务费专项(编号:0009-2014G1271062)资助. （编号:41330315）
