“盆”“山”耦合和脱耦的反转点和切入点研究

AN APPROACH TO THE STUDY OF INVERSION POINTS AND TANGENCY-IN POINTS FOR OROGENY AND COUPLED/DECOUPLED BASIN DEVELOPMENT

吴根耀 马力

Wu Genyao Ma Li

中国科学院, 地质与地球物理研究所, 北京, 100029 2. 中国石油化工集团公司, 江苏油田, 江苏, 扬州, 225009

Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 2. Jiangsu Oilfield, SINOPEC, Yangzhou, Jiangsu 225009, China

反转构造的反转点和“盆”“山”关系的切入点是“盆”“山”耦合和脱耦研究的方法论中的关键问题。抓准抓好反转点,一是要深刻认识中国大地构造特征所决定的“盆”“山”关系的复杂性,二是要全面了解区域内“盆”“山”耦合和脱耦的关键问题。“盆”“山”关系的切入点,既应视具体的研究对象多方位、多角度、多层次、多侧面地确定,也要强调首要的和必要的切入点是造山作用的类型。抓对反转点的必由途径是“盆”“山”研究中把“正序”与“反序”结合起来而以“反序”的研究为主,文章简要介绍了反序地编制“盆”“山”演化图的经验。反转点和切入点的确定体现在盆地研究中,是在给予时间约束和厘定盆地含义的前提下正确认识盆地的世代更迭和各世代的构造格架及构造样式,特别是正确认识重大构造运动时期的盆地世代更迭。“盆”“山”耦合和脱耦的反转点和切入点研究的突破,必将造成盆地研究生动活泼的新局面,进而给残留海相盆地的油气勘探带来新的启示。

The study of orogeny and coupled/decoupled basin development regarded orogeny and basin development as a whole and explored a uniform kinematic process and geodynamic mechanics between the both. The key of methodology for the study was to grasp, correctly and practically, inversion points and tangency-in points, the former representing obvious changes of tectonic patterns or styles, and the latter constituting a key link connecting basins with orogeny. For the inversion points, we should, first of all, understand the essential problems of orogeny and coupled/decoupled basin development in a given regional framework. In addition, the tectonic features of Chinese continent decided the difficulties and complexities of discerning inversion points, which supported, in turn, a wide platform for the study of tengency-in points. The tangency-in points might be decided by a poly-direction, poly-visual angle, poly-level and poly-aspect means, in which the orogenic types and structural styles should be the first important and necessary one. As the road one must take for the study of inversion points and tangency-in points, a combination of "normal succession" and "reversal succession" was emphasized, with stress on the study of "reversal succession". Namely, regional evolution and basin development should be worked from the ancient to the present, and the oil-gas accumulation analysed from the young structural layers to the older ones. The paper introduced some experiences to compile some profiles, perpendicular to the regional tectonic strike, across both an orogen and neighbouring basins. With the inversion points and tangency-in points being embodied in the basin research, the alternation of basin generations as well as tectonic patterns and structural styles in each generation should be correctly distinguished, particularly, to distinguish the basin generations changed in the periods of main tectono-thermal events. The prerequisite for understanding basin generations was to constrain a geohistorical phase and to stipulate a basin definition. The advances in the study of inversion points and tangency-in points for orogeny and coupled/decoupled basin development must open up a new prospect of the basin research, and then draw a new inspiration in the oil-gas exploration of relict marine basins.

https://doi.org/10.11781/sysydz200501008