海相油气地质2018，Vol.23Issue(1)：13-20,8.DOI:10.3969/j.issn.1672-9854.2018.01.002
甘肃平凉地区奥陶系平凉组重力流与等深流交互作用的沉积研究
Interaction Between Gravity Flow Deposits and Contourite Deposits in the Ordovician Pingliang Formation, Pingliang Region,Gansu Province
摘要
Abstract
The interaction between gravity flow deposits and contourite deposits has been researched based on the outcrop in Ordovician Pingliang Formation of Pingliang region in Gansu province.It is shown that calcarenite and shale are the mainly lithology of Pingliang Formation, and partly with some calcirudite. It is determined that five typical lithofacies include horizontal bedding shale, massive calcirudite, massive calcarenite, graded bedding calcarenite and lenticular cross bedding calcarenite, which correspond to in situ deep-water deposits, debris flow deposits, turbidites and contourites. The energy of the contour current which moved from east to west paralleling to the slope, might be enhanced in the confined environments of Qinling-Qilian Trough. The scale of gravity flow deposits became weaker from the bottom up in Pingliang Formation,while the scale of contourite deposits became stronger. It is concluded that gravity flow was active and the effect of contour current was weak when the relative sea-level was low, and vice versa. The early gravity flow deposits can be subject to transpotation,reconstruction,redeposition by the contour current and then contourites come into being,on the contrary, it is possible that the early contourites are eroded and destroyed by the gravity flow.关键词
鄂尔多斯盆地/奥陶纪/平凉组/浊流/碎屑流/等深流Key words
Turbidity current/Debris flow/Contour current/Pingliang Formation/Ordos Basin分类
能源科技引用本文复制引用
严世帮,李华,王季欣..甘肃平凉地区奥陶系平凉组重力流与等深流交互作用的沉积研究[J].海相油气地质,2018,23(1):13-20,8.基金项目
本文受国家自然科学基金项目"鄂尔多斯盆地西南缘中奥陶统重力流与等深流交互作用沉积研究"(编号:41502101)资助 （编号:41502101）
