构造控制下的西沙海槽沉积模式

Xisha Trough Depositional Model under Controlling by Structure

构造控制沉积,不同的构造背景有不同的沉积模式。晚中新世强烈的构造沉降在琼东南盆地中央坳陷带形成了西沙海槽。周边特殊的区域构造背景使得唯有红河水系得以从西面进入西沙海槽,形成了顺槽底搬运的河流沉积体系。物源补给控制海槽边坡类型。槽底河流沉积体系与海槽北坡上部的悬浮沉积体系和下部的浊流滑塌沉积体系一起构成了西沙海槽沉积模式。

The deposition is controlled by structure controls. The depositional models are different under different structure back-ground. Xisha Trough was formed in the Central Depression of Qiongdongnan Basin due to the intensive tectonic subsidence in the late Miocene. Because of the special regional structure backgrounds in the surroundings, the water from Red River flowed into Xisha Trough from northwest, and fluvial system developed along bottom of Xisha Trough. The slope styles of Xisha Trough was control- led by source supplying rate. Xisha Trough Depositional Model consisted of fluvial system at trough bottom, suspended depositional system in the upper part of north slope of the trough, turbidite and slump system in in the lower part of north slope of the trough.