柴达木盆地北缘东部侏罗系发育特征

侏罗系是柴达木盆地主力生油层，主要分布于盆地北缘。通过对柴北缘侏罗系标志层、岩性特征和沉积体系的综合研究，明确了主要露头剖面侏罗纪不同时期的沉积相类型。本区侏罗系主要发育 5 种类型沉积相，包括冲积扇、辫状河、扇三角洲、辫状河三角洲和湖泊，相带的展布和古地理演化均与区域构造运动密切相关。根据侏罗系内部及其与上下地层的接触关系和沉积旋回演化，柴达木盆地北缘东部经历了早--中侏罗世断陷湖盆沉积到晚侏罗世挤压坳陷沉积两大沉积演化阶段。

Development characteristics of Jurassic in northeast margin of Qaidam Basin

Jurassic is the main source rocks of Qaidam Basin，distributed mainly in the northern margin of the basin． Based on the comprehensive studies of marker beds，lithological features and sedimentary characteristics， the alluvial fan facies，braided river facies，fan delta facies，braided river delta facies and lacustrine facies are distinguished in Jurassic deposits in the main sections exposed． Both the facies belt distribution and paleogeographic evolution are closely related to the regional tectonic movement． There are two evolution stages that include the faulted lake basin sedimentary stage from Early to Middle Jurassic and the depression lake basin sedimentary stage during Late Jurassic，according to the stratigraphic contact relations and sedimentary evolution．