利用等厚度法分析台湾海峡盆地西部坳陷形成演化过程

An Analysis of the Formation and Evolution Process in the Western Depression of the Taiwan Strait Basin by Using the Equal Thickness Method

台湾海峡盆地西部坳陷是我国海上油气勘探程度较低的含油气坳陷,是否存在油气资源是目前急需解决的问题,而明确沉积演化特征可为讨论该区域油气地质条件研究提供依据。本文通过识别地震标准层,明确地层分布,利用等厚度法恢复沉积演化历史,揭示坳陷的形成过程。研究表明该坳陷经历了坳陷阶段(晚白垩世-晚古新世)、断陷阶段(早始新世-早中新世)、陆架边缘阶段(中中新世-晚中新世)和前陆盆地阶段(上新世至今)4个演化阶段。

The western depression of Taiwan Strait basin is a kind of oil and gas bearing depression with low degree of offshore oil and gas exploration in China and the question of whether there is oil and gas resources is urgently needed to be solved at present.The clear characteristics of sedimentary evolution can provide a basis for discussing the geological conditions of oil and gas in the region.In this paper,the history of sedimentary evolution is restored by identifying seismic standard layers,defining stratigraphic distribution and using the method of uniform thickness.The results show that the depression experienced four stages:the depression stage(late Cretaceous to late Paleocene),the fault stage(early Eocene to early Miocene),the continental shelf margin stage(Miocene to late Miocene)and the foreland basin stage(Pliocene to present).