川西北地区震旦系顶面古地貌演化剖面的建立及其解析

Establishment of Sinian top Paleo-topography evolutionary section in Northwest Sichuan Province and its analysis

为丰富古地貌演化分析实践和深入剖析其演化细节、内幕及其地质响应过程,在详细介绍目的层古地貌图切剖面建立的一般方法基础上,结合研究区实际情况,构建了川西北地区以震旦系顶面为目的层的古地貌演化剖面。对其进行了细致的解析表明,震旦系顶面在泥盆—石炭纪和晚三叠世经历了古地貌正变换过程,二叠纪经历了一次负变换过程。燕山—喜马拉雅期是九龙山构造圈闭继承性规模发育和最终定型的关键时期,也是成藏运聚调整的关键时期。该研究为古地貌演化、尤其是其剖面演化提供了重要实例,提高了古地貌及其演化横纵向对比的灵活性和准确性,拓宽了古地貌研究辐射地质领域,加深了其地质响应过程的认识,为油气勘探开发实践和油气地质理论研究提供了新的实例支撑。

Paleo-topography evolutionary section,based on the general constructing methods of objective paleo-topography cut-out section,was established according to practical geological situations in order to further enrich paleo-topograhpy evolution analysis practices and deeply examine the evolutionary details and inside processes and their geological responses.The careful examination of Sinian top paleo-topography evolution section revealed that Sinian top experienced two positive transformations during the Devonian-Carboniferous and Late Triassic periods,one negative transformation during Permian,while Jiulongshan structural trap experienced inherited giant development and then formed finally during the Yanshan and Himalayan periods which were also key hydrocarbon accumulation periods.The study provided an important example for paleo-topography evolution,especially for paleo-topography section evolution investigation,and enhanced the correlation accuracy and flexibility of horizontal and vertical paleo-topography and its evolution,broadened paleo-topography radial geological application range,while it deepen the knowledge of geological responding processes of the paleo-topography evolution,and provided new evidences and foundation for petroleum exploration and development and petroleum geological theory.