渤海湾盆地新生代沉降特征及其动力学机制探讨  

CENOZOIC SUBSIDENCE IN BOHAI BAY BASIN:CHARACTERISTICS AND DYNAMIC MECHANISM

作　　者：郭兴伟[1] 施小斌[1] 丘学林[1] 吴智平[2] 杨小秋[1] 肖尚斌[1] 

机构地区：[1]中国科学院边缘海地质重点实验室 [2]石油大学地球资源与信息学院,山东东营257061

出　　处：《大地构造与成矿学》2007年第3期273-280,共8页Geotectonica et Metallogenia

基　　金：国家自然科学基金项目(编号40676041;40204006);国家973项目(G2000046701);中国科学院南海海洋研究所与广州地球化学研究所边缘海地质重点实验室基金项目(MSGL0511)

摘　　要：综合分析了渤海湾盆地新生代以来断裂发育的分布规律,以及伸展量和沉积沉降随时间和空间的变化规律,并结合现今的深部结构特征,试图揭示盆地新生代沉降的地球动力学机制。发现在断陷阶段,断裂发育在时间和空间上控制了沉积沉降中心的迁移;坳陷阶段后期,在断裂作用非常弱的情况下,以渤中坳陷为中心,出现裂后加速沉降现象,并逐渐波及到相邻坳陷。断陷阶段的断裂发育和沉积沉降主要受板块运动形成应力场的控制,其沉降是岩石圈水平伸展和岩石圈垂向热减薄耦合作用的结果;而裂后加速沉降可能是岩石圈垂向密度突然变化及其后迅速热衰减造成的。The characteristics of development and distribution of Cenozoic faults, amount of extension, and the temporal-spatial variation rules for subsidence of sediments in Bohai Bay Basin were analyzed based on previous study results. Analysis of the deep structures was made to investigate the dynamic mechanism for the Cenozoic subsidence. The results show that in the uplifting period development of faults controls the transition of deposition or subsidence centers, while at the end of the depressing period, accelerated subsidence whose center is Bozhong Depression occurs and shows a tendency of transition from the center to its adjacent depressions. It can be concluded that development of faults, deposition, and subsidence was controlled by the stress field generated from the plate movement, and subsidence of sediments was resulted from the horizontal extension and vertical thermal thinning of lithosphere in the uplifting period. The accelerated subsidence of sediments in the postrift uplifting period may result from the vertical change in density of the lithosphere and its following quick thermal decay.

关 键 词：渤海湾盆地 新生代 断裂 伸展量 加速沉降 

分 类 号：P542[天文地球—构造地质学] P618.13[天文地球—地质学]