辽河西部凹陷西南部沙一、二段沉积体系与层序地层特征

Sedimentary system and sequence stratigraphy of s_l and s_2 member in southwest of Liaohe western depression

在调查研究的基础上 ,对辽河西部凹陷西南部地区沙一、二段沉积体系及层序地层特征进行了论述。研究认为 :该区沙一、二段沉积体系为辫状河三角洲 ,并组成了一个完整的I型三级层序 ,其中低位体系域主要由辫状河、辫状河三角洲平原及前缘组成 ,沉积作用以加积为主 ;湖侵体系域由辫状河三角洲前缘、前三角洲及浅湖组成 ,以退积为主 ;而高位体系域由辫状河三角洲前缘与湖相组成 ,以进积为主。同时认为 ,低位体系域成藏条件好 ,是本区有利的勘探目标。

This paper discusses the sedimentary system and sequence stratigraphy of S 1 and s 2 member in southwest of Liaohe western depression on the basis of investigation.The study shows that.sedimentary system of s 1 and s 2 member was braid fiver delta,which was a complete sequence of type I of the third level; the low-stand system tract mainly consisted of braid fiver, braid river delta plain and front,with aggradation as major form of sedimentation;lake transgressive system tract consisted of braid river delta front,predelta and shallow lake,with retrogradation as the major form;high-stand system tract consisted of braid river delta front and lacustrine facies.with progradation as the major form.In the meantime,it is thought that the low-stand system has good reservoir forming conditions,and is a favorable exploration target in this area.