塔里木盆地东部古生代中期伸展构造的发现及其地质意义

通过地震资料解释，首次在塔里木盆地东部发现了古生代中期的伸展构造。它们是一系列正断层，以及由这些正断层组合成的雁列状张扭性断层带。正断层走向近N-S；雁列状张扭性断层带分两组，走向分别是NE-SW和NW-SE，构成一个共轭体系，显示近E-W向的拉张作用。根据断层生长指数、断层断开的地层单元和断层断距变化的解析，这些伸展构造的形成时间是中志留世—中泥盆世。它们是原特提斯阿尔金早古生代碰撞造山带的碰撞后构造，是判定塔里木地块—柴达木地块碰撞造山作用结束时间的重要证据。

The Mid-Paleozoic extensional structures revealed in the eastern Tarim Basin and their geological significance

On the basis of careful seismic interpretation, the Mid-Paleozoic extensional structures were discovered for the first time in the East Tarim Basin. They are normal faults and their constituent echelons. The normal faults strike in nearly N-S direction. They form two groups of transtensional fault zones, which strike in NE-SW and NW-SE respectively forming a conjugate system showing nearly E-W extension. According to the fault growth indexes, age of the strata cut by the faults and the change of the fault displacements, these extensional structures were formed in Middle Silurian-Middle Devonian. They are the post-collision structures of the Altun Early Paleozoic collisional orogenic belt which is a Proto-Tethyan suture. It is also a key evidence for timing the end of the Tarim-Qaidam collision.