Deep-Water Contour Currents Deposits of Upper Ordovician Lashizhong Formation in Western Margin of Ordos Basin

被引：2

作者：

Li X. ^{[1
]}

Chen H. ^{[1
]}

机构：

[1] Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming

来源：

Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences | 2020年 / 45卷 / 04期

关键词：

Contour currents deposit; Ordos basin; Paleo-current; Sedimentary structure; Sedimentology; Upper Ordovician;

D O I：

10.3799/dqkx.2019.119

中图分类号：

学科分类号：

摘要：

In order to reduce the gap between contemporary oceanographic studies and geological records in the study area of deep-water contour currents deposits, and to explore the significance of ocean circulation system on marine deep water oil and gas exploration in Middle to Upper Ordovician of western margin of Ordos basin, it was perform paleo-currents-analyses and hydrodynamics using sedimentary structures based on detailed field observations. The results show that: (1)There are 1/3 small cross beddings with paleo-currents directions perpendicular to the regional slope direction; (2)sedimentary structures with bi-directional progressive grain-size change are ubiquitous in deep-water turbidity currents channel, which include parallel (ripple laminae)-homogeneous - parallel (ripple laminae) sequence, stripped-and-banded structures and inverse to normal grading sequence (grain size). All these sedimentary characteristics maybe suggest the deep-water contour currents deposits according to the perpendicular flow direction and the rhythmic lithologic properties which coincide with the period of contour currents. Here it was also recognized two contourites types: deep-water non-channel contourites and turbidity currents channel contourites, and the latter includes two subtypes with partial reaction and entire reaction. © 2020, Editorial Department of Earth Science. All right reserved.

引用

页码：1266 / 1280

页数：14

共 41 条

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