论文部分内容阅读
万安盆地为新生代发育于减薄陆壳之上的走滑拉张盆地,基底主要由中生代花岗岩类与变质岩组成,经历了早第三纪张裂与晚第三纪裂后两个发育阶段,张裂阶段断陷期沉积了厚达6100m的河湖相—海陆交互相与半封闭浅海相沉积,裂后期为大规模海进期,沉积了厚达4000m的浅海—半深海相沉积,巨厚的新生代沉积奠定了形成大型含油气盆地的基础。盆地内大规模的基底块断活动形成了三隆四坳的构造格局,控制了各类圈闭的发育,以与基岩有关的继承性圈闭最为重要,具有极为良好的油气勘探前景。
The Wanan basin is a strike-slip extension basin developed in the Cenozoic over the reduced continental crust. The basement is mainly composed of Mesozoic granitoids and metamorphic rocks, and underwent two stages of early Tertiary and later Tertiary rifting Stage, the rift phase of the rifting stage deposited a sedimentary thickness of up to 6100m of the lacustrine facies-sea-land interaction facies and the semi-closed shallow marine facies, and the late-cleavage stage was a large-scale marine stage. The shallow sea-semi-deep marine sediments up to 4000m thick were deposited, The huge Cenozoic sediments have laid the foundation for the formation of large petroliferous basins. Large-scale basement block faulting in the basin formed the structural pattern of the Sanlongqiao depression and controlled the development of various traps. Inheriting traps associated with bedrock are the most important and have very good prospects for oil and gas exploration.