库车坳陷北部白垩系露头层序地层分析

THE ANALYSIS OF CRETACEOUS OUTCROP SEQUENCE IN NORTH KUCHE DEPRESSION

应用丰富的露头资料,以沉积体系分析为基础,以层序地层学的沉积相响应为主线对库车坳陷北部白垩系沉积体系类型及其沉积相类型进行了系统分析,并按照高分辨率层序地层学原理对研究区的目的层段进行了层序划分。(1)沉积体系分析,通过对野外露头的观察,岩样的成分、粒度分析,将研究区白垩系划分为湖泊体系、扇三角洲体系、辫状河三角洲体系和三角洲体系等四种类型;(2)露头层序地层分析,研究区白垩系与上覆的库姆格列木群呈角度不整合,为研究区一级层序界面,根据地层露头沉积体系垂向演化特征结合高分辨率层序地层学原理将该区白垩系划分为8个三级层序。

In this paper rich outcrop material was used. Through the research of depositional systems and the sedimentary response to sequence stratigraphy, different types of depositional systems and their faces were recognized and the sequence was divided in the conception of High Resolution Sequence Stratigraphy. (1) Analysis of sedimentary systems. Through the observation of wild outcrop of Cretaceous of the study area, lake system, fan-delta system, braided river delta system and the Delta system, these four types of sedimentary systems were identified. (2) Outcrop sequence stratigraphic analysis. In the study area, between Cretaceous and the overlaying layer Kumugeliemu Group was an ungle-unconformity and the unconformity surface was recognized as the interface of 1 st level sequence. According to the vertical evolution of sedimentary system of outcrop eight 3rd level sequences were identified in the study area of Cretaceous.