吉林榆树地区榆东、榆西断陷构造特征及演化史分析  

Structural features and tectonic evolution history of Yudong and Yuxi fault depressions of Yushu area in Jilin Province

作　　者：李多姿 孙晓猛[1] 董清水[1] 刘长利[1] 何松[1] 郑涵[1] 万阔[1] 

机构地区：[1]吉林大学地球科学学院,长春130061

出　　处：《世界地质》2015年第3期675-683,共9页World Geology

基　　金：中国地质调查局项目(12120113098100);吉林油田项目(JS12-W-13-JZ-7-40)联合资助

摘　　要：通过地震剖面系统解释,识别出断陷的结构和构造特征,运用平衡剖面的原理及方法,进行了断陷的构造演化史分析。研究结果表明:榆东、榆西断陷分别沿榆东断裂和榆西断裂呈近SN向分布,两个断陷之间为榆树凸起。以榆树凸起为中心,两个断陷分别是由同向正断层组所组成的西断东超和东断西超的复合半地堑,它们共同组成了相背式半地堑组合。在榆东断陷中分布一条近EW向展布的次级凸起,分隔了北部洼槽和南部洼槽,它是十分有利的油气聚集区。笔者还对比了两个断陷的构造样式、构造反转、断陷强度、地层残留厚度和最大埋深等方面的差异;识别出榆树地区火山岩的分布特征主要受SN向的榆东基底断裂、NNE向的榆西基底断裂、NWW向的新立镇基底断裂和NEE向的农安—榆树岩石圈断裂交叉控制;讨论了断陷形成以及火山喷发与华北板块和东北中小地块群发生碰撞、蒙古—鄂霍茨克洋盆的关闭、Izanagi板块斜向俯冲和岩石圈拆沉减薄之间的关系。In order to offer the geological basis for the research on oil and gas in deep exploration in Yushu area,the authors systematically analyze the recognized structural and tectonic features by surveying the seismic sections and the tectonic evolution history by using the theory and method of balanced section. The results show that the Yudong and Yuxi fault depressions strike in SN direction and run along the Yudong and Yuxi faults,respectively. The Yushu embossment is located between the two depressions. Centerally on the Yushu embossment,the two fault depressions are composite-half-grabens which comprise a series of normal faults with the same dips and have the feature of fault in the west but overlap in the east and fault in the east but overlap in the west,respectively. The two fault depressions constitute an opposite-type semi-graben. In the middle part of the Yudong fault depression,there is a sub-embossment which strikes in EW direction and separates the depression into north and south sags,which are good hydrocarbon accumulation zone. The authors also compare the differences of structural type,structural inversion,depression intensity,thickness of residual strata and maximum burial depth,which identifies the distribution characteristics of volcanic rocks are mainly controlled by Yudong basement fault of SN strike,Yuxibasement fault of NNE strike,Xinlizhen basement fault of NWW strike and Nongan-Yushu lithospheric fault of NEE. The fact demonstrates that the formation of faults and eruption of volcanos are closely related to the collision between the North China Plate and NE China massif group,the closure of Mongol-Okhotsk ocean basin,the oblique subduction of Izanagi Plate,and the delamination and thinning of the lithosphere.

关 键 词：榆东断陷 榆西断陷 构造特征 构造演化 吉林省 

分 类 号：P542[天文地球—构造地质学]