沧东凹陷始新统孔店组二段深水细粒沉积岩中的软沉积物变形构造  

Soft-sediment deformation structures in deepwater fine-grained sedimentary rocks of the Member 2 of Eocene Kongdian Formation,Cangdong sag

作　　者：鄢继华[1,2] 焦玉玺 陈世悦 邓远[1] 蒲秀刚 

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [2]青岛海洋科学与技术国家实验室海洋矿产资源评价与探测技术功能实验室,山东青岛266071 [3]中国石油大港油田分公司勘探开发研究院,天津300280

出　　处：《古地理学报》2017年第1期89-98,共10页Journal of Palaeogeography：Chinese Edition

基　　金：国家自然科学基金项目(编号:41572087);中央高校基本科研业务费专项(编号:15CX06004A)联合资助~~

摘　　要：湖相深水细粒沉积岩中的软沉积物变形构造主要发育在泥岩和泥晶碳酸盐岩为主的地层中,大部分因为发育规模小(镜下尺度),在岩心观察中很容易被忽略掉。本文以沧东凹陷G108-8井孔店组二段(孔二段)细粒沉积岩为研究对象,通过密集的镜下观察和精细岩心描述,识别出同沉积微断裂、液化岩脉、微褶皱变形、微重荷变形和杂乱变形等多种类型的软沉积物变形构造。研究区深水细粒沉积岩中的软沉积物变形构造总体表现为规模小、垂向无明显重力流砂体伴生、原地成因、沉积纹层发育等特点。从应力调节方式的角度考虑,可以将软沉积物变形构造的形成机制划分为上覆应力卸载、侧向应力挤压和层内应力释放等3种类型,不同的形成机制分别是对不同沉积环境变化的响应。通过湖相深水细粒沉积岩软沉积物变形构造的研究,可以恢复古沉积环境变化、预测重力流方位,对深水细粒沉积岩的油气勘探也具有一定的指导意义。The soft-sediment deformation structures in fine-grained sedimentary rocks of deepwater lacustrine are mainly developed in strata of mudstone and micritic carbonate rocks. Most of the soft-sediment deformation structures are prone to be ignored in the core observation because of the small size（microscopic scale）. The authors take Well G108-8 in the Member 2 of Eocene Kongdian Formation in Cangdong sag as research object to identify the synsedimentary micro fracture,liquefied vein,micro fold deformation,micro weight deformation,random deformation and other types of soft-sediment deformation structures through the intensive microscopic observation and elaborate core description. The soft-sediment deformation structures formed in deepwater fine-grained sedimentary rocks in the study area overall have characteristics like small scale,no association of obvious gravity flow sand body in vertical,in situ origin,sedimentary laminae developed and so on. The formation mechanism of soft-sediment deformation structures can be divided into the overlying stress unloading,lateral extrusion stress and internal stress release from the view point of the styles of stress adjustment,and the different formation mechanisms response to multiple changes of sedimentary environments. The research of soft-sediment deformation structures formed in deepwater fine-grained sediments of lacustrine can reconstruct the changes of ancient sedimentary environments and predict the gravity flow direction. It also has a great guiding significance to oil and gas exploration in the deepwater fine-grained sedimentary rocks.

关 键 词：湖相深水沉积 细粒沉积岩 软沉积物变形 孔二段 沧东凹陷 成因分析 

分 类 号：P315.2[天文地球—地震学] P512.2[天文地球—固体地球物理学]