鄂尔多斯盆地北部下奥陶统层序地层学研究  

Sequence Stratigraphy of Lower Ordovician Strata in North Part of Ordos Basin

作　　者：刘家洪[1] 陈洪德[1] 侯明才[1] 苏中堂[1] 万梨[1] 

机构地区：[1]成都理工大学沉积地质研究院

出　　处：《海相油气地质》2009年第1期51-56,共6页Marine Origin Petroleum Geology

摘　　要：以露头剖面、钻井岩心为研究对象,结合测井地质特征,对鄂尔多斯盆地北部下奥陶统层序界面特征及其成因类型进行了深入研究。将下奥陶统划分为10个三级层序,其中冶里组两个(SQ1,SQ2),亮甲山组两个(SQ3,SQ4),马家沟组一段至马家沟组六段各划分出一个(SQ5—SQ10)。层序SQ1—SQ4都表现为向上变浅的结构特征;层序SQ5—SQ7反映了区域上的海侵过程,总体为潮下环境,以加积序列为特征;层序SQ8反映了区域上的最大海浸,以大量凝缩段沉积为特征。由于加里东运动影响,层序SQ9—SQ10仅在研究区西缘和东南缘出露,西缘以盆地相深水沉积为特征,东南缘以发育潮坪相沉积为特征。According to outcrop profiles, drilling cores and well-loggings, the characteristic of sequence boundary and the type of boundary of Lower Ordovician strata are studied in the north part of Ordos Basin. The Lower Ordovician can be divided into 10 third-order sequences, which are SQ1 and SQ2 of Yeli Formation, SQ3 and SQ4 of Liangjiashan Formation,SQ5 to SQ10 of Member 1 to Member 6 of Majiagou Formation. Sequences SQ1 to SQ4 are characteristic of shallowing-upward structure. Sequences OSQ5 to OSQ7 show regional transgression that is characteristic of aggradation under the subtidal environment.Sequence SQ8 reflects the maximum transgression with characteristics of volumes of condensed succession in this area. Due to affection of Caledonian event, crops of Sequence SQ9 to SQ10 exist only in the western and southeastern edges of this area,in which basinal deep-water sediments develop in the western edge and tidal flat sediments do in the southeaster edge.

关 键 词：层序地层 层序界面 地层特征 早奥陶世 鄂尔多斯盆地 

分 类 号：P534[天文地球—古生物学与地层学] TE111.3[天文地球—地质学]