中国侏罗纪构造变革与燕山运动新诠释  

Jurassic Tectonic Revolution in China and New Interpretation of the Yanshan Movement

作　　者：董树文[1] 张岳桥[1,2] 龙长兴[1] 杨振宇[1,2] 季强[3] 王涛[3] 胡建民[1] 陈宣华[1] 

机构地区：[1]中国地质科学院地质力学研究所 [2]南京大学地球科学系,210093 [3]中国地质科学院地质研究所

出　　处：《地质学报》2007年第11期1449-1461,共13页Acta Geologica Sinica

基　　金：国家自然科学基金(编号40572120);大陆深俯冲作用(编号1999055);中石化项目<大巴山前陆演化与油气远景>联合资助项目的成果。

摘　　要：随着一系列新构造观察资料和高精度同位素测年数据的累积,加深了对发生在中国东部晚侏罗世—早白垩世时期构造变革事件的认识,对燕山运动的性质、时限和动力学内涵有了新的诠释。中—晚侏罗世初期(165±5Ma)东亚多板块拼贴运动学发生重大调整,构造体制发生重大转换,启动了以中朝地块为中心、来自北、东、南西不同板块向东亚大陆"多向汇聚"的构造新体制,形成以陆内俯冲和陆内造山为特征的东亚汇聚构造体系。同时大陆地壳岩石圈发生显著增厚,并紧随早白垩世以剧烈的大陆岩石圈伸展和火山—岩浆活动为特征的岩石圈巨量减薄和克拉通破坏,导致燕辽生物群灭绝和热河生物群兴盛的重大生物群更替,成为中国大陆和东亚重大构造变革事件,这是燕山运动的基本内涵。本文依据燕山运动构造变形型式、动力学背景以及产生的深部过程,将"燕山运动"定义为起始于165±5Ma的"东亚多向汇聚"构造体制及其形成的广泛陆内造山和构造变革,并将中国东部岩石圈巨量减薄视作燕山期陆内造山和陆内变形的后效。With acquisition and accumulation of new data of structural investigations and high resolution isotopic dating data, we have greatly improved our understanding of the tectonic events occurring in eastern China during the period from the Late Jurassic to Early Cretaceous and may give a new interpretation of the nature, timing and geodynamic settings of the “Yanshan movement”. During the Mid Late Jurassic （165±5 Ma）, great readjustment of plate amalgamation kinematics took place in East Asia and the tectonic regime underwent great transformation, thus initiating a new tectonic regime in which the North China block was the center and different plates converged toward the East Asian continent from the north, east and southwest and forming the “East Asia convergent” tectonic system characterized by intracontinental subduction and orogeny. As a consequence, the crustal lithosphere of the East Asian continent thickened considerably during the Late Jurassic, followed immediately by Early Cretaceous substantial lithospheric thinning and craton destruction featured by drastic lithospheric extension and widespread volcano-magmatic activities, resulting in a major biotic turnover from the Yanliao biota to Jehol biota. Such a tremendous tectonic event that took place in the continent of China and East Asia is the basic connotation of the “Yanshan movement”. In the paper, according to the deformation patterns, geodynamic settings and deep processes, the “Yanshan movement” is redefined as the Late Jurassic East Asian muhidirectional plate convergent tectonic regime and its associated extensive intracontinental orogeny and great tectonic change that started at -165±5 Ma. The substantial lithospheric attenuation in East China is considered the post- effect of the Yanshanian intracontinental orogeny and deformation.

关 键 词：晚侏罗世 燕山运动 东亚多向汇聚 陆内造山与变形 岩石圈增厚与减薄 

分 类 号：P534.42[天文地球—古生物学与地层学]