新疆准噶尔盆地南缘拉张伸展动力学环境的探讨

DISCUSSION ON THE EXTENSIONAL DYNAMIC SETTING IN THE SOUTH BORDER OF JUNGGAR BASIN, XINJIANG,CHINA

准噶尔盆地南缘在中生代、甚至新生代很长一段时间处于拉张伸展环境。至新生代晚期才转换成挤压环境。本文从六个方面对拉张伸展动力学环境进行了探讨，指出了准噶尔盆地南缘伸展构造与后期反转构造的研究对这一地区油气运移规律的探讨具有重要意义。结合生油岩系的生油高峰期分析，中生代的伸展构造与二叠纪、侏罗纪生油岩系的生油高峰是配套的，它们形成的断块，同沉积背斜等对捕获早期油气起着决定性作用。

s: The tectonic dynamic setting in the south border of Junggar Basin has been generally considered as a Mesozoic Cenozoic compressive basin. In the discussion of tectonic evolution and strutural deformation ,only compressive regime and compressive structure were considered,whereas the extensional situation and structure were ignored. In this paper,based on field survey and analysis of former materials,it is proposed that the tectonic dynamic regime of the south border of Junggar Basin should be extensional setting during Mesozoic and even a long period of Cenozoic era.1t did not become a compress ive setting until late Cenozoic era.Six aspects about this viewpoint are demonstrated.Finally,combining with the peak period of oil generating,it is found that extensional structures(fault block,syndepositional anticlines) were important for capturing early stage oil and gas,and the Mesozoic extensional structures and later inversion structures should be considered attentively in future study of gas oil structural traps.