中国主要克拉通前寒武纪裂谷分布与油气勘探前景

发布时间：2018-02-25 01:30

本文关键词： 前寒武纪裂谷超大陆华北克拉通塔里木克拉通扬子克拉通　出处：《石油学报》2017年01期 　论文类型：期刊论文

【摘要】：利用地质、地球物理和钻井资料编制中国主要克拉通盆地长城系、蓟县系和南华系残余厚度图,初步查明中-新元古代裂谷分布。华北和扬子克拉通中-新元古代裂谷中心以一套由粗快速变细的裂陷层序为标志,从目前的裂谷期地层等时对比格架上判断,现今鄂尔多斯盆地和四川盆地腹部的中-上元古界烃源岩均不如盆地覆盖区外的裂谷中心区域发育。塔里木克拉通南部和北部新元古代裂谷则具有不同的展布特征、形成时间和成因演化,塔里木南部的裂谷活动与以华南大陆(由扬子克拉通和华夏克拉通构成)为中心的地幔柱作用有关,而塔里木北部的裂谷主要形成于罗迪利亚超大陆外侧泛大洋俯冲引起的弧后伸展作用。塔里木南部裂谷开启时间较华南晚约20~40 Ma,但比塔里木北部提前至少40 Ma。前寒武纪裂谷演化对早寒武世沉积盆地具有重要的控制,使得后者具有"向前相似"而不是"向后相似"的特点。在塔里木和扬子,早寒武世盆地与南华纪—震旦纪裂谷盆地具有显著的继承性关系;在华北,青白口纪裂谷活动中心向东南缘移位控制了早寒武世盆地的发育位置和海侵方向。就目前的研究程度而言,中国古老克拉通前寒武纪裂谷的类型和分布特征仍显示出动力学上的多样性和复杂性,因而在充填演化和勘探价值研究上也有不同的观点和结论。近期研究除应继续加强地球物理资料处理,以更精细落实盆地覆盖区隐伏裂谷和裂陷外,也应重点开展裂谷期层序识别、地层对比和充填模式建立工作,努力解决前寒武纪裂谷类型及其演化的动力学问题,以恢复与烃源岩沉积阶段的盆地原型,查明烃源岩分布规律。
[Abstract]:Using geological, geophysical and drilling data, the residual thickness maps of the Great Wall, Jixian and Nanhua systems in major cratonic basins in China are compiled. The distribution of the Meso-Neoproterozoic rift valley was preliminarily identified. The center of the North China and Yangtze Craton Meso-Neoproterozoic rift valley is marked by a set of rifting sequences that have changed rapidly from coarse to thin, judging from the current rift epoch stratigraphy on the Biger framework. The Mesoproterozoic source rocks in the middle and upper Proterozoic basins of the Ordos basin and Sichuan basin are not as well developed in the central region of the rift outside the basin cover area, while the southern and northern Neoproterozoic rift basins in the southern and northern Tarim cratons have different distribution characteristics. The rift activity in southern Tarim is related to the mantle plume centered on the South China continent (consisting of the Yangtze craton and the Huaxia craton). The rift in the northern part of Tarim was mainly formed by the back-arc extension caused by the panoceanic subduction on the outer side of the Lodilla supercontinent. The southern rift of Tarim was opened about 2040 Maa later than southern China, but at least 40 Maa earlier than the northern part of Tarim. The evolution of Cambrian rift basin has important control over the early Cambrian sedimentary basin. In Tarim and Yangtze, the early Cambrian basin and the South China-Sinian rift basin have a remarkable inheritance relationship; in North China, The movement of the active center of the Qingbakou rift to the southeastern margin controlled the development position and transgression direction of the early Cambrian basin. The type and distribution of the Precambrian rift valley in ancient China still show dynamic diversity and complexity. Therefore, there are different viewpoints and conclusions in the study of filling evolution and exploration value. In recent studies, apart from continuing to strengthen geophysical data processing in order to more precisely implement the hidden rift and rifting in the covered area of the basin, Emphasis should also be placed on the identification of rift sequences, stratigraphic correlation and establishment of filling models, in order to solve the dynamic problems of Precambrian rift types and their evolution in order to restore the basin prototype in the sedimentary stage of source rocks. The distribution law of source rock is found out.
【作者单位】：中国石油勘探开发研究院;中国石油集团东方地球物理勘探有限责任公司研究院长庆分院;北京大学地球与空间科学学院;
【基金】：中国石油天然气股份有限公司科技项目“油气勘探新领域、新理论、新方法、新技术研究”(2014A-02)资助
【分类号】：P618.13;P534.1

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