大陆边缘动力沉降及其深部构造作用控制

Continental margin dynamic subsidence and its deep tectonic control

动力沉降是动力地形的一种,即动力地形低。动力地形一般认为具有两种成因,一种为与超大陆集聚和分散有关的动力地形,另一种为与大洋板片俯冲有关的动力地形。大陆边缘动力沉降的模拟已经提出了不同的动力学模型,如大洋板块缓倾角或陡倾角俯冲模型、不同样式(俯冲角度变化和速度变化)和性质(大洋岩石圈热年代变化等)的大洋板块俯冲模式和具应力引导的、动态三维的板块俯冲模型。关于大陆边缘动力沉降及其深部板块俯冲作用控制的研究已经趋向更加符合实际、更加精细和系统。对深部地幔活动及其地表动力地形响应的深入研究有望对关于大陆边缘区高级别层序单元及其界面的成因机制、大陆内部动力沉降与深部构造作用之间的耦合关系、我国晚中生代至新生代大陆边缘区动力学背景和油气资源评价等问题的研究取得新的进展和突破。

The dynamic subsidence is one of dynamic topography, that is, dynamic topography low. It is generally thought that the dynamic subsidence is associated with supercontinental assembly and dispersal and subducting slabs. Scientists have proposed several different models of subduction to simulate the dynamic subsidence of continental margins,which include the first one with dip angle change from shallow to steep, the second one with dip angle, rate and thermal age change of subducting slab, and the third one of three dimensional evolution with stress guide. Study of the deep mantle process and its dynamic topographical response will provides more insights about formation mechanism of megasequence and its boundaries, coupling relation between dynamic subsidence in continent and deep tectonic process, and geodynamic setting and hydrocarbon resource distribution of the continental margins in late Mesozoic and Cenozoic in China.