石油与天然气地质 ›› 2022, Vol. 43 ›› Issue (6): 1271-1291.doi: 10.11743/ogg20220601

• 油气地质 •    

鄂尔多斯克拉通地块活化了吗?

何登发1(), 包洪平2, 开百泽1, 许艳华1, 鲁人齐3, 张才利2, 魏柳斌2, 成祥1   

  1. 1.中国地质大学(北京) 能源学院,北京 100083
    2.中国石油 长庆油田分公司 勘探开发研究院,陕西 西安 710018
    3.中国地震局 地质研究所,北京 100029
  • 收稿日期:2022-06-16 修回日期:2022-08-22 出版日期:2022-12-01 发布日期:2022-11-21
  • 第一作者简介:何登发(1967—),男,博士、教授,盆地构造与油气地质综合研究。E?mail: Hedengfa282@263.net
  • 基金项目:
    中国石油长庆油田公司科技攻关项目(ZDZX2021-01)

Has the Ordos Block, a cratonic block been reactivated?

Dengfa He1(), Hongping Bao2, Baize Kai1, Yanhua Xu1, Renqi Lu3, Caili Zhang2, Liubing Wei2, Xiang Cheng1   

  1. 1.School of Energy Resources,China University of Geosciences (Beijing),Beijing 100083,China
    2.Institute of Exploration and Development,Changqing Oilfield Company,PetroChina,Xi’an,Shaanxi 710018,China
    3.Institute of Geology,China Earthquake Administration,Beijing 100029,China
  • Received:2022-06-16 Revised:2022-08-22 Online:2022-12-01 Published:2022-11-21

摘要:

克拉通地块在演化过程中的活动性是大陆保存状态研究的核心内容,克拉通不同程度的活动性与油、气、煤、铀和盐类等矿产资源密切相关,制约着板内的地震活动,因此是能源、资源与环境研究的热点之一。以华北克拉通西部的鄂尔多斯地块为例,以地块内部的深井与高精度反射地震剖面为基础,揭示了鄂尔多斯地块的构造活动性,并将这种活动性称之为“活化”。研究表明,自中元古代以来,鄂尔多斯克拉通地块的活化表现在6个方面:①地块内部或周缘发育了中元古代、寒武纪—早奥陶世、石炭纪—早二叠世、中-晚三叠世与新生代等5期裂陷或伸展活动;②地块内部发育了中-新元古代、奥陶纪、晚石炭世、中-晚三叠世、早白垩世与中新世晚期—第四纪等6期岩浆活动,尤以长城纪、早白垩世岩浆活动为盛;③发育了7个时期的断裂系统及断层相关褶皱;④发育了长城系与前长城系、蓟县系与前蓟县系、震旦系与前震旦系、寒武系与前寒武系、奥陶系与前奥陶系、石炭系与前石炭系、三叠系与前三叠系、侏罗系与前侏罗系、白垩系与前白垩系、第四系与前第四系等10个区域性不整合面;⑤经历了中-新元古代、早古生代、石炭纪—三叠纪与侏罗纪—白垩纪等4个构造沉降旋回,沉降中心发生明显迁移;⑥新生代地块周缘地区快速裂陷并沉降充填,内部则隆升剥蚀,地块周缘及内部均发生了一系列强震活动。鄂尔多斯地块的演化受周缘板块构造背景与深部构造活动的强烈控制,早白垩世的岩石圈可能经历了大规模减薄,新生代晚期地块北部的岩石圈发生活化和减薄,这与鄂尔多斯地块逆时针旋转、上地幔物质部分熔融及其沿周缘地堑系薄弱带上侵有关。鄂尔多斯地块已发生了较明显的活化,活化事件对成盆、成烃与成藏可能具有重要意义。

关键词: 岩浆活动, 区域不整合面, 裂谷作用, 构造沉降, 构造迁移, 克拉通活化, 鄂尔多斯地块

Abstract:

The activity of a cratonic block during its evolution is the key in studying the continental preservation. Cratonic block reactivation of diverse scales is in close relation to mineral deposits such as oil, gas, coal, uranium and salt, and controls the intra-plate earthquake activity, thus has been one of the hot topics in the field of energy, resource, and environment researches. The Ordos Block located in western North-China craton (NCC), is taken to reveal its tectonic activities, referring to as “reactivation” in the study. The analysis of deep boreholes and high-resolution reflection seismic profiles, indicates that the reactivation of the Ordos Block can be shown in six aspects as follows. First, five stages of rifting or extension in or around the block occurred during the Mesoproterozoic, the Cambrian to Early Ordovician, the Carboniferous to Early Permian, the Middle to Late Triassic, and the Cenozoic; second, there were six stages of magmatism in the block during the Middle to Late Proterozoic, the Ordovician, the Late Carboniferous, the Middle to Late Triassic, the Early Cretaceous, and the Late Miocene to Quaternary, with the magmatic events coming to peak during the Changchengnian Period and the Early Cretaceous; third, there were seven stages of faulting and development of faulting-related folds; fourth, there are ten regional unconformities developed including the Ch/AnCh, Jx/AnJx, Z/AnZ, C?/AnC?, O/AnO, C/AnC, T/AnT, J/AnJ, K/AnK, and Q/AnQ; fifth, the block underwent four tectonic subsidence cycles of the Middle to Late Proterozoic, the Early Paleozoic, the Carboniferous to the Triassic, and the Jurassic to Cretaceous, with a marked migration of the subsiding centers; and sixth, a number of strong earthquakes occurred along the peripheries and the interior of the Ordos Block with the interior uplifting while the periphery rifting and rapidly subsiding during the Cenozoic. The evolution of the Ordos Block is predominantly controlled by the adjoining plate tectonics and the deep tectonic activities, to some extent with a possible large-scale thinning of the lithosphere in the Early Cretaceous, and also the reactivation and thinning of the lithosphere in northern part of the Ordos Block during the Late Cenozoic, which is resulted from the anti-clockwise rotation of the block, and thus the upward intrusion of the partial molten melts of the upper mantle along the weak zones of the graben systems around. The Ordos Block therefore took typical properties of reactivation, which may have played a profound role in the basin formation, the hydrocarbon generation, and the pool-formation in the block.

Key words: magmatism, regional unconformity, rifting, tectonic subsidence, tectonic migration, cratonic reactivation, Ordos Block

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