欧亚大陆及边缘海岩石圈的结构特性  

The structural characteristics of lithosphere in the continent of Eurasia and its marginal seas

作　　者：朱介寿[1] 

机构地区：[1]成都理工大学,四川成都610059

出　　处：《地学前缘》2007年第3期1-20,共20页Earth Science Frontiers

基　　金：国家自然科学基金重点项目(40234047;49734150;40474032);高校博士点学科基金项目(20050616001);油气藏地质及开发工程国家重点实验室及地球探测与信息技术教育部重点实验室项目

摘　　要：欧亚大陆及其边缘海地区是由约30多块尺度不同、形成时代和性质各异的板块或地块拼合而成。这些岩石圈板块或地块经过长时间的漂移,多次聚合与分离,碰撞与增生,在新生代最后形成现代的拼合欧亚大陆。欧亚大陆及其边缘海的板块或地块可以分为以下六类:(1)前寒武纪巨型克拉通地块及地盾;(2)前寒武纪小型克拉通地块及板块;(3)显生宙造山带及汇聚地块;(4)陆陆碰撞型地块及造山带;(5)新生代边缘海海盆;(6)大陆裂谷盆地及增生地块。高分辨率地震面波层析成像,显示同一类型的板块或地块的岩石圈和软流圈的速度结构十分相似,呈现出其独有的速度分布特征。不同类型板块或地块的速度结构有重大差异。直到400km深度,各个板块和地块的横向差异才逐渐减小。一般而言,前寒武纪克拉通板块及地块的岩石圈巨厚具有高速性质、软流圈很薄或不存在;边缘海、造山带等区域岩石圈较薄和速度较低,软流圈发育。根据欧亚大陆及边缘海地区天然地震层析成像,人工地震剖面数据及其他有关资料,建立了欧亚大陆及其边缘海岩石圈模型。The continent of Eurasia and its surrounding marginal seas are assembled by more than thirty plates and blocks with different scales, characteristics, and different ages. These plates and blocks were formed through drifting, converging, separating, colliding, and accreting throughout much of Earth＇s history, finally resulting in the present assembled plate of Eurasi＆ The plates and blocks in Eurasia and its surrounding marginal seas can be divided into six types： （1） large Precambrian cratonic plates or shields; （2） small Precambrian cratonic plates or blocks; （3） Phanerozoic orogens; （4） continent-continent collisional orogens; （5） Neozoic marginal sea basins; （6） continental rift basins. High-resolution surface wave tomographic images indicate that the velocity characteristics of the lithosphere and asthenosphere are quite similar for the same type of plates or blocks. However, the velocity characteristics are different for different types of plates or blocks. The lateral changes in velocity for different plates or blocks decrease to the depth of 400 km and beyond. In general, Precambrian cratonic shields show high velocity, huge thickness and do not have an asthenosphere zone. On the other hand, marginal seas, rift systems and orogens show lower velocity and have thick asthenospheric zones. We collected all three-dimensional images and explosion seismic data of both crust and lithosphere in Eurasia, and constructed a model of the lithosphere in Eurasia and its surrounding marginal seas. We discuss the structure and the characteristics of lithosphere in detail.

关 键 词：欧亚大陆 拼合的岩石圈板块或地块 高分辨率地震面波层析成像 岩石圈板块速度分布 欧亚大陆及边缘海岩石圈模型 

分 类 号：P54[天文地球—构造地质学] P31[天文地球—地质学]