琼东南盆地渐新统陵水组坡折带类型及层序地层样式

Slope-break types and sequence stratigraphic styles of the Oligocene Lingshui Formation in Qiongdongnan Basin, South China Sea

张亚雄 朱筱敏 陈欢庆 张功成

Zhang Yaxiong Zhu Xiaomin Chen Huanqing Zhang Gongcheng

以沉积学、层序地层学和石油地质学理论为基础，在琼东南盆地渐新统陵水组层序地层格架的基础上，识别出了断裂型和挠曲型两种坡折带类型，并阐述了各种坡折带的特点以及对沉积体系的控制和影响作用，同时相应建立了单断型箕状断陷式和断阶式两种层序地层样式。单断型箕状断陷式层序地层样式往往发育于具一条主控凹断裂的箕状凹陷中，按构造几何形态可分为凹陷边缘陡坡带、凹陷中心深陷带以及凹陷边缘缓坡带3个构造区带。断阶式层序地层样式主要是在一条主断裂的控制下、多条与主断裂走向平行的次级断裂共同作用构成的一种特殊的层序地层几何样式。系统研究了各层序地层样式的分布，剖析了各层序地层样式内部沉积体系的展布。研究表明，各层序中的低位域砂体和高位域砂体为有利的勘探目标。

Based on the theories of sedimentology,sequence stratigraphy and petroleum geology,this paper identified two types of slope-break including fault slope-break and flexure slope-break on the basis of sequence framework of the Oligocene Lingshui Formation in Qiongdongnan Basin.We also documented the features of each slope-break and their control and influence on the sedimentary systems.Two kinds of sequence styles including single fault half graben-like type and step fault type are recognized in the Lingshui Formation.The former sequence style commonly occurs in a half graben basin with one main boundary fault and can be divided into a margin steep slope zone,a deep center zone and a margin gentle slope zone.While the later sequence style mainly develops in a basin under the joint control of one main boundary fault and many secondary faults parallel with the boundary fault.This paper also studied the distribution of each sequence style and its inner structure characteristics.The results indicate that the sandbodies of low system tract and high system tract are the favorable targets for future hydrocarbon exploration.

10.11743/ogg20140405