中央造山带东段岩石圈的构造格架  

Tectonic framework of the eastern segment of the Central orogenic belt of China

作　　者：杨文采[1] 

机构地区：[1]中国地质科学院地质研究所,国土资源部大陆动力学重点实验室,北京100037

出　　处：《中国地质》2005年第2期299-309,共11页Geology in China

基　　金：国家重大基础科研973项目(2003CB716505);国土资源部重点基础项目(20001010203)共同资助。

摘　　要：笔者讨论了大别—苏鲁超高压变质带地球物理调查剖面及相关地球物理成果。分析大别—苏鲁地体的深部地质构造与岩石圈主要特征,并与东秦岭地区前人的探测结果进行对比。结果认为,中央造山带东段的地壳构造反映了扬子克拉通向北的陆内深俯冲作用。陆壳俯冲的角度在20°～30°之间,由于角度较缓,中央造山带东段发育了开阔的后陆盆地,其下方基底构造仍保留有造山带板块会聚的特征。造山带核部上中地壳存在着规模很大的岩浆岩体的显示,与造山期后的地质作用有关。大别—苏鲁的早中生代超高压变质带在东秦岭可能仍埋藏在地壳深处,不会出露于地表。The author presents the main results of the latest geophysical investigations in the Dabie-Sulu ultrahigh-pressure (UHP) metamorphic belt, analyzes the general characteristics of the lithospheric structures in the Dabie-Sulu terrane, and makes a comparison of these characteristics with those beneath the East Qinling and Tongbai terranes observed by previous workers. The crustal structure in the eastern segment of the Central orogenic belt reflects the northward deep intracontinental subduction of the Yangtze craton. The continental crust was subducted at angles of about 20°-30°. As the subduction angles were gentle, an open backland basin developed in the eastern segment of the orogenic belt, and the basement structure below the basin still has the characteristics of the plate convergence of the orogenic plate. The manifestations of large-scale magmatic intrusions occurring in the upper-mid crust in the cores of the orogenic belt were related to post-orogenic geological processes. The Early Mesozoic Dabie-Sulu UHP metamorphic belt might still exist at the deep levels of the crust below the East Qinling and will not be exposed on the surface today.

关 键 词：岩石圈结构 超高压变质带 大别-苏鲁 东秦岭 地球物理调查 中央造山带 

分 类 号：P313[天文地球—固体地球物理学]