四川叠合盆地盆山耦合特征分析

四川叠合盆地三面环山,自东而西夹持于江南、秦岭与龙门山三大山系之间,位于古亚洲、环太平洋与特提斯三大构造域的结合部位;中生代以来,先后经历了海盆、煤盆、陆相广盆、残盆四个盆地世代;盆地沉积充填过程可概括为前陆、坳陷、再生前陆三种基本样式。系统的山盆构造样式及运动学、沉积充填过程分析结果表明盆地周缘造山带造山活动期与盆内古隆起发育期时间耦合;盆地周缘造山带造山活动期与盆地沉积环境转换期时间耦合;盆地周缘造山带构造轴线走向基本保持与盆内山前坳陷或前陆褶冲带构造轴线走向相耦合;盆地周缘造山带不同时期形成的褶冲构造轴线走向基本保持与其同期盆内产生的沉积或沉降中心构造轴线走向相耦合。

CHARACTERS OF COUPLING BETWEEN MESOZOIC SEDIMENTARY BASIN AND OROGENIC BELT IN SICHUAN OVERLAIN BASIN AND ITS ADJACENT AREA

Sichuan overlain basin is located among the Jiangnan, Qinling-Dabie and Longmen orogenic belts, and at the juncture among ancient Asia, Circum-Pacific and Tethys. It has undergone four basin generation episodes, i.e., marine basin, coal basin, continental basin and relict basin, since Mesozoic. The sedimentary filling processes in the basin can be generalized as three modes, i.e., foreland, depression and reactivated basin. On the basis of analysis of the tectonic evolution, kinematics and sedimentary filling of the basin together with its orogens, we discover the coupling between the movement period for the peripheral orogens of the basin and the formation period of the ancient uplift in the basin in terms of time, the coupling between the movement period of the peripheral orogens of the basin and the transformation period of sedimentary environment in the basin in terms of time, the coupling between the strike for the tectonic axis of the peripheral orogens and that for the tectonic axis of the piedmont depression or the foreland fold-fault belts in the basin, the coupling between the strike for the tectonic axis of the foreland fold-fault belts and that for the tectonic axis of the syntectonic sedimentary or depression center formed in different periods.