论胶东地区中生代岩石圈减薄的证据及其动力学机制

胶东地区可划分为两个大地构造单元：胶北断块和胶南造山带。前者为华北板块组成部 分,后者为华北和扬子板块的碰撞拼合带。五莲－青岛－海阳－牟平深断裂构成上述两个构造单 元的边界。本文从地质（陆壳隆升、构造岩浆活动与断陷盆地形成）和地球物理（重、磁异常与地震 测深）两个方面论述了胶东地区中生代经历了两个不同构造演化时期：前期（Ｔ３－Ｊ２）陆壳隆升和后 期（Ｊ－Ｋ）陆壳拉伸。我们认为,岩石圈减薄的动力学条件是与库拉－太平洋板块以不同边界类型 向欧亚大陆俯冲以及郯庐断裂以不同方式的强烈活动密切相关。在综合分析基础上建立了胶东地 区岩石圈减薄的动力学模式。

DISCUSSION ON TIE EVIDENCES OF MESOZOIC LITHOSPHERE THINNING AND ITS DYNAMIC MECHANISM IN JIAODONG AREA

Jiaodong area is located in the eastern part of Shandong Province, which can be divided into two tectonic units: Jiaobei fault-block and Jiaonan orogenic belt. They are one part of North China plate and the collision orogenic belt between North China plate and Yangtze Plate, respectively. Wulian-Qingdao-Haiyang-Mouping fault is the boundary of above two tectonic units. Two different stages of tectonic evolution during the Mesozoic in Jiaodong area have been studied in this thesis from geological(continental crustal uplift, tectonic magmatic activites and the formation of the down fault-subsidence basin) and geophysical information(gravity and magnetic anomaly and seismic sounding). It is apparent that Jiaodong area had undergone the continental crustal uplift of the earlier stage(T3-J2) and the continental crustal stretch of the later stage(J3-K). We have proposed that the dynamic condition of lithosphere thinning is relative to the subdution of the Kula-Pacific Plate beneath the Euro-Asia Plate with different plate boundary types and the variously intensive activities of Tan-Lu fault. The dynamic model of lithosphere thinning in Jiaodong area is set up on the base of comprehensive analysis.