吐－哈盆地大地构造环境分析──兼论大陆板内盆地与造山带的成因关系

Tectonic Environmental Analysis of Turpan-Hand Basin On the Genetic Relationship Between Basin and Orogenic Belt of Continental inner Plate

学术界普遍认为吐－哈盆地为板块碰撞作用所形成的压（扭）性盆地。本文研究发现，吐－哈盆地在沉积演化、构造变形、盆地结构、地球物理场及其所反映的壳幔结构等方面都与中国东部张性伸展盆地具有相似的特征；盆地自晚二叠世发育起，经历了两次（Ｐ２—Ｊ，Ｋ—Ｒ）持续稳定而漫长的伸（扩）展演化，其间在侏罗纪末期和第四纪早期，盆地伸展与沉积受到两次短暂挤压作用的遏制而中断，同时改造了盆地长期形成的伸展构造。盆地伸展是由于“地幔底辟”作用，而两次挤压作用（火焰山运动和西域运动）则是由于盆地伸展，使其南、北邻区遭受挤压变形而长期积累应力，以至于在短时间内发生断裂作用并释放应力而反作用于盆地的结果。从而本文提出吐－哈盆地为张性伸展盆地这一新的观点；结合有关模拟实验结果，同时提出“地幔底辟—盆地伸展—两侧挤压变形与应力积累—应力释放—伸展与沉积中断”的大陆板内地球动力学与运动学模式。

The academic circles hsve considered Turban-Hami BaSin is a compredonal one by Plate collision, but the reSearch Of this paper Showes Turban-Halni Basin is SAnest to the extensional akins Of East China in many ways, such as sedimental evolution, structural deformation, basin texture and crust-mantle texture renected by the drihar gcophysic fields and so on.From the lute Permian Period, Turban-Hami Basin bead develOPing and kept up a stagy spreading two cycles for a very long time(P2-J2,KZ-N2).Two comptessional tectogenods (Huoyanshan and Xiyu) took Place and the two spreading and sedimentary cycles were checked by the two movementS in the hate Jurassic and the end of the Tertiary Period, respectivelly, and the extensional structure of the ban was reformed at the same times.The basin extension is a result Of the mantle diapirism. Due to the basin extension, the adjacent regions (Tianshan Orogenic Belt) north and south to the basin had been compressed.and deformed plastically (folding and upwarping). The stress accumulated with the plastic deformations in the rocks was so stronger thst fsulting took plsce, releaSing the stress. The compredonal movements occured when the faulting reacted on the basin, and the sedimentation discolltinued.Combining the geological features with experimental results, we propose a new viewpoint that Turban-Hami Basin is a extensional basin. Thus a new theory or model about the dynamics and kinematics of continental inner plate is dotribed as follows:maneal diapirism- adn extension- folding and accumulsting stress in adjaCent regions (orogenic beltS)-releasing the stress-basin lifting and sedimentation discontinuance.