摘要
基于测录井资料对比,结合区域构造演化特征,将草湖凹陷侏罗系划分为两个三级层序J-SQ1与J-SQ2。J-SQ1时期气候温暖潮湿,层序发育完整的上升半旋回和下降半旋回沉积,发育辫状河体系和湖泊体系;J-SQ2时期气候逐渐转为炎热半干旱,层序发育不完整,只发育上升半旋回沉积,主要由氧化型湖泊体系构成,发育滨浅湖砂滩、泥滩互层沉积。其中,J-SQ1早期辫状河河道砂体叠置厚度大,储层物性好,上覆中厚层湖相泥岩沉积,是本区有利的储集层段。
The Jurassic strata in the Caohu depression,Tarim Basin,Xinjiang are divided,on the basis of well logs and regional tectonic evolution,into two third-order sequences J-SQ1 and J-SQ2.During the deposition of J-SQ1 sequences,the climates were warm and humid.The sequence displays the complete rising-falling semicyclic deposits.Till the deposition of J-SQ2 sequences,the climates turned into hot and semiarid ones.The sequences display only the rising semicyclic deposits,and consists of oxidized lacustrine depositional systems in which the littoral-shallow lacustrine sand-mud beach deposits are developed.The braided channel sandstones in J-SQ1 sequences are believed to be the favourable reservoir rocks in the study area due to tremendous thickness,better physical properties and moderate to thick overlying lacustrine mudstone.
出处
《沉积与特提斯地质》
CAS
CSCD
2011年第1期1-5,共5页
Sedimentary Geology and Tethyan Geology
基金
国家十一五重大科技专项(2008ZX05002)
关键词
草湖凹陷
侏罗系
沉积体系
层序地层
Caohu depression
Jurassic
depositional system
sequence stratigraphy