摘要
长期以来,由于埋藏深、地质复杂及自然条件恶劣等原因,银根-额济纳旗及邻区石炭系—二叠系的油气勘查程度低,相关研究成果少。鉴于此,本文充分利用研究区的周缘露头,借助近30条剖面的详细调查,分析了本区石炭系—二叠系的沉积特征。研究表明,本区石炭系—二叠系包括了泥岩、砂岩、砂砾岩、碳酸盐岩和火山岩(或火山碎屑岩)等,海相生物丰富。暗色泥岩是石炭系—二叠系的主体,是潜在的烃源岩和盖层;火山岩(或火山碎屑岩)发育,碳酸盐岩多呈透镜状且硅化普遍,砂砾岩相对较少,三者构成石炭系—二叠系重要储层。岩石组成及展布特征表明,石炭纪—二叠纪期间,本区张裂频繁,火山作用强烈,远离陆源区,水体深而宁静,利于生烃物质发育。期间,区内主要发育了浅海相、广海海岸相、碳酸盐台地相、辫状三角洲相、扇三角洲相和火山喷发相等沉积类型。其中,浅海相和局限海岸相主要形成了烃源岩和盖层,其他沉积则形成了储层,为区内石炭系—二叠系造就了良好的油气地质条件。
A study on depositional characteristics is very important for petroleum geology exploration. Relatively less research and exploration here, however, have been made due to their deeply-buried, geological-complicated and bad-natural conditions, and etc. Therefore, this study focused on the depositional characteristics of Permo-Carboniferous systems by taking full use of the outcrops in surrounding area and detailed investigation for nearly 30 profiles. The results show that Permo-Carboniferous formation comprises mudstones, sandstones, sandy conglomerates, carbonate rocks, volcanic rocks （or pyroclastic rocks）, etc., accompanied by a large amount of marine organism. Dark mudstone dominates of the Permo-Carboniferous formation, and is a potential source for hydrocarbon and cap rocks. The main reservoirs of the Permo-Carboniferous consist of widely-developed volcanic rocks （or pyroclastic rocks）, lenticular and silicated carbonate rocks, and minor sandstones and sandy conglomerates. The lithological compositions and distribution pattern also reveal that frequent faulting and strong volcanism concurring in the study area, along with deep water body are highly advantageous to generation of hydrocarbon. The main depositional types contain neritic shelf, open coast, carbonate platform, braided delta, fan delta and volcanic eruption etc, among which both neritic shelf and barrier coast form the source rocks and cap rocks, and other facies make up reservoirs for oil and gas respectively. This provides advantageous conditions of oil and gas for the Permo-Carboniferous systems.
出处
《地质学报》
EI
CAS
CSCD
北大核心
2010年第8期1183-1194,共12页
Acta Geologica Sinica
基金
中国地质大调查项目(编号1212010733506)资助的成果
关键词
沉积相
沉积特征
油气地质
海平面变化
石炭纪—二叠纪
额济纳旗
内蒙古
depositional facies
sedimentary characteristics
change in sea level
petroleum geology
Perm-Carboniferous
Ejinaqi
Inner Mongolia
作者简介
赵省民，男，1964年生。博士．研究员，从事沉积学、层序地层学和石油地质学研究。通讯地址：100037，北京市百万庄大街26号，中国地质科学院矿产资源研究所；Email：xxmmzh@163．com。
