中国东部盆地喜山运动Ⅱ幕研究现状及问题

PROGRESS ON THE SECOND EPISODE OF HIMALAYA MOVEMENT AND PRIMARY DISCUSSION ON THE EXISTING PROBLEMS IN BASINS OF EASTERN CHINA

刘士林 肖焕钦 林舸 鲁国明 张德圣 夏永健 彭美丽

Liu Shilin Xiao Huanqin Lin Ge Lu Guoming Zhang Desheng Xia Yongjian Peng Meili

中国科学院, 广州地球化学研究所, 边缘海地质重点实验室, 广州, 510640 2. 中国科学院, 研究生院, 北京100039 3. 中国石化, 胜利油田有限公司, 山东, 东营, 257000

Key Laboratory of Marginal Sea Geology, Guangzhou Institute of Geochemistry, CAS, Guangzhou, Guangdong 510640, China 2. Graduate School, Chinese Academy of Sciences, Beijing 100039, China 3. Shengli Oil field Company, SINOPEC, Dongying, Shandong 257000, China

渐新世末至早中新世,喜山运动Ⅱ幕促使中国东部新生代含油气盆地由断陷沉降向整体坳陷转变,造成古/新近系地层的广泛不整合、盆内次级断层发育以及局部地区的正反转构造等特征;并且造成不整合面附近地层的沉积体系发育特征由渐新世末的滨浅湖、冲积扇和河流—三角洲相沉积为主到中新世的冲积扇—辫状河相沉积为主的转变。文中重点探讨了喜山运动Ⅱ幕活动时限、剥蚀程度、对油气成藏影响以及动力学机制等仍需解决的几个关键问题。其中剥蚀恢复研究是解决这些问题的关键,综合利用声波时差、磷灰石裂变径迹以及镜质体反射率等多种剥蚀恢复手段可以有效地研究喜山运动II幕的剥蚀程度。喜山运动II幕的成因主要存在板块碰撞导致的走滑挤压模式和岩石圈弹性回返模式的争议。

The change of subsidence model in Cenozoic petroliferous basins of Eastern China which goes from rifting subsidence stage in the Late Oligocene to whole thermal subsidence in the Early Miocene was caused by the second episode of Himalaya Movement.This movement resulted in some typical structure phenomena which are characterized by extensive unconformity in Eogene/Neogene strata,by the formations of secondary faults,and by the positive reverse structures in local areas.Accordingly,it caused the change of sedimentary systems in the up and down strata of E/N unconformity which was characterized by shore-shallow lacustrine facies,alluvial fan and fluvial-deltaic facies in the Oligocene to alluvial fan and braided fluvial facies in the Miocene.Four key problems were mainly discussed to elucidate the movement entirely,including the active period constraints,the denudation degrees,the effect on hydrocarbon reservoirs and its dynamic mechanism.Note that denudation degree research is the most important problem to this movement.Multiple methods(e.g.apatite fission track technique,vitrinite reflectance and acoustic time method) can be effectively used to reconstruct the denudation thickness of the second episode of Himalaya Movement.About this movement,there are chiefly two possible dyna-mic mechanisms.One is the transpressional mechanism related to the collision of plates;the other is the rebound mechanism of lithosphere.

国家自然基金项目(40773004);中国科学院基金项目(MSGL07-23)

https://doi.org/10.11781/sysydz200802121