古地理学报 ›› 2022, Vol. 24 ›› Issue (4): 697-712. doi: 10.7605/gdlxb.2022.04.056

• 岩相古地理学及沉积学 • 上一篇    下一篇

鄂尔多斯盆地早侏罗世富县期沉积演化: 大洋缺氧事件前后陆地气候变化的响应*

李昌昊1,2, 葛禹1,2, 金鑫1,2, 时志强1,2   

  1. 1 成都理工大学沉积地质研究院,四川成都 610059;
    2 成都理工大学油气藏地质及开发工程国家重点实验室,四川成都 610059
  • 收稿日期:2021-12-22 修回日期:2022-03-03 出版日期:2022-08-01 发布日期:2022-08-09
  • 通讯作者: 时志强,男,1972年生,成都理工大学沉积地质研究院教授。E-mail: szqcdut@163.com
  • 作者简介:李昌昊,男,1994年生,成都理工大学沉积地质研究院在读硕士研究生。E-mail: 634891625@qq.com。
  • 基金资助:
    *国家自然科学基金项目(编号: 41902106,41572085)资助

Sedimentological evolution during the Early Jurassic Fuxian period in Ordos Basin: palaeoclimatic response to Toarcian Oceanic Anoxic Event

LI Changhao1,2, GE Yu1,2, JIN Xin1,2, SHI Zhiqiang1,2   

  1. 1 Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu 610059,China;
    2 State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China
  • Received:2021-12-22 Revised:2022-03-03 Online:2022-08-01 Published:2022-08-09
  • Contact: SHI Zhiqiang,born in 1972,is a professor of Institute of Sedimentary Geology,Chengdu University of Technology.E-mail: szqcdut@163.com.
  • About author:LI Changhao,born in 1994,is a master degree student in Institute of Sedimentary Geology,Chengdu University of Technology. E-mail: 634891625@qq.com.
  • Supported by:
    National Natural Science Foundation of China(Nos. 41902106,41572085)

摘要: 托阿尔期早期早侏罗世大洋缺氧事件(T-OAE,~183.8 Ma)是一次全球性的地质事件,鄂尔多斯盆地下侏罗统富县组记录了此次地质事件的陆地响应过程。主要基于盆地东缘野外地质调查、扫描电镜及薄片分析,本次研究描述了盆地东北部富县组岩性、颜色和沉积序列,利用前人研究成果总结了富县期岩相古地理变化规律及沉积模式,认为富县期经历了由干旱到湿润的古气候变化: 富县组下部含植物化石较为丰富的白色砂砾岩及黑色、灰色泥页岩沉积于湿润气候时期,对应着盆地下切河谷发育期和填平补齐期; 而上覆的罕见植物化石的杂色、红色泥页岩为(富县期晚期)相对平坦地形条件下的沉积,对应着早、中侏罗世湿润气候背景下的一次干旱气候脉动,为托阿尔期大洋缺氧事件在陆相环境的气候响应,可由此进行富县组区域等时性对比。研究认为“粗富县”为下切谷内河流充填沉积, “细富县”形成于湖泊环境或河漫环境, “黑富县”和“白富县”是湿润气候条件下沉积产物,而“红富县”和“杂富县”为T-OAE期后干旱条件下形成。

关键词: 侏罗纪古气候, 富县组, 托阿尔期海洋缺氧事件, 岩相古地理, 鄂尔多斯盆地

Abstract: As a global geological event,the early Toarcian(Early Jurassic)Oceanic Anoxic Event(T-OAE)(~183.8 Ma)affected both the marine and terrestrial environments. The response of this event had been recorded in the Lower Jurassic Fuxian Formation in the Ordos Basin. Based on the field geological survey,scanning electron microscopy and thin section analysis,we studied the lithology,color changes and sedimentary sequence of the Fuxian Formation in the northeastern Order Basin. Together with the previous research results of literature,we revealed the lithofacies palaeogeography and sedimentary model of the Fuxian period. Our results show that the Ordos Basin had experienced the palaeoclimatic change from wet to drought during the Fuxian period. The white glutenite and black or gray mudstone/shale containing abundant plant fossils deposited in the humid conditions,which corresponds to the filling stage of valleys in the basin. After filling up,the variegated and red mudstone/shale containing few plant fossils deposited in the flat topographical condition during the late Fuxian period,corresponding to an arid climate pulse under the overall humid climate in the Early and Middle Jurassic periods. The changes of rock color and climate are interpreted as the continental response of the T-OAE,which can be used for the isochronous correlation of the Fuxian Formation. We interpret the “coarse Fuxian”was fluvial deposits filling the incised valleys,the “fine Fuxian”deposited in lake or flood plain environments,the “black Fuxian”and “white Fuxian”were sedimentary products of humid climate,while “variegated Fuxian”and “red Fuxian”deposited under drought climate condition after the T-OAE.

Key words: Jurassic palaeoclimate, Fuxian Formation, Toarcian Oceanic Anoxic Event(T-OAE), lithofacies palaeogeography, Ordos Basin

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