塔里木盆地克拉通内古隆起的成因机制与构造类型

古隆起是克拉通盆地的重要构造单元。由于盆地边界条件与深部构造背景的变化,古隆起的形成与发育表现为复杂的动力学过程。借助于地震反射剖面与钻探资料,可以刻画不同地质时期古隆起的分布、形态、结构与构造样式,剖析古隆起的成因机制。文中以塔里木盆地为例,对古生代克拉通内古隆起的几何学与运动学特点进行描述,结合周缘大地构造背景的演变,剖析了古隆起的形成机制。在此基础上,将克拉通内古隆起划分为稳定型、活动型、残余型与消亡型4种基本类型。由于运动体制的变革,古隆起经历了形成发育、叠加改造、调整定型与最终埋藏的动力学演变,具有多层叠加的地质结构,并发育断裂带、背斜带、地层剥蚀尖灭带等一系列构造带。古隆起是油气聚集的主要单元,古隆起的动力学演化历史决定了隆起富集油气的关键条件。

Formation mechanism and tectonic types of intracratonic paleo-uplifts in the Tarim basin

Paleo-uplift is an important structural element in a cratonic basin.Its formation and evolution have undergone a complicated dynamic process owing to the variation both in the basin boundaries and in the background of deep structures.By the application of seismic reflection profiles and drilling data,we are able to describe the paleo-uplift in detail pertaining to its distribution,configuration,framework,structural style as well as the formation mechanism.As a case study of the Tarim basin,the paper addresses the geometric and kinematic features of Paleozoic cratonic paleo-uplifts,and discusses its formation mechanisms by integrating with the evolution of the peripheral geo-tectonic settings;and further classifies the paleo-uplifts into four basic types such as the stable one,active one,remnant one,and the disappeared one.With the change of movement regimes,the paleo-uplift has undergone such a complex dynamic history from forming,growing,superposing and modifying,adjusting and shaping to burying finally.It thus shows a structure of superposition of multiple structural layers,and develops a series of fault belts,anticlinal belts,stratigraphy truncated and thinned belts.Paleo-uplifts are the dominant areas for the accumulation of oil and gas,while its dynamic evolution has significant influence upon the key conditions for hydrocarbon migration,accumulation,and enrichment in the paleo-uplift area.