柴达木盆地断裂发育特征及其动力学机制探讨

以精细地震解释为依托，以平衡剖面技术为手段，对柴达木盆地的地质发展演化史及在不同构造动力学背景下形成的断裂构造系统进行了分析。分析表明，在“挤压+走滑”的区域应力场作用下，柴达木盆地形成北部、南部和西北部3大挤压走滑断裂系统，断裂以逆断层和走滑断层为主，并伴有少量的同沉积正断层、滑脱断层、反转断层等。平衡剖面复原表明，柴达木盆地断裂的形成演化主要有3类模式：（1） 断裂在中新世（N1）定型；（2） 断裂在上新世(N2)—第四纪(Q)期间发育形成；（3）在盆地形成演化过程中一直都在活动的长期发育的断裂。这些断裂的生成和发展经历了侏罗纪的扩张、古近纪的初步挤压反转、新近纪大幅度逆冲走滑、第四纪最终定型等阶段。

THE KINEMATIC CHARACTERISTICS OF THE FAULT SYSTEM OF QAIDAM BASIN AND ITS DYNAMIC MECHANISM

Based on the precise seismic interpretation and by means of cross-section technique，we analyze the geological evolution history of the Qaidam Basin and the unique fault structure system which was formed in different tectonic dynamic backgrounds.It is suggested that with the compressional effect and strike-slip regional stress，three fault systems (northern，southern and north-west)are formed in Qaidam Basin.These faults are reverse and strike-slip faultones mostly，and accompanied by a small number of synsedimentary faults，detachment faults，and inverted faults，etc.The restorations of the balanced seismic sections indicate that the generated times of the faults are different.Some of them are formed within Miocene；some are formed from Pliocene to Quaternary separately，and the others are active in the whole process of basin evolution history.These faults have undergone the expansion in Jurassic，the initial compression in Paleogene，the large amplitude compressional strike-slip in Neogene before they fell into patterns in Quaternary.