石油与天然气地质 ›› 1988, Vol. 9 ›› Issue (4): 410-420.doi: 10.11743/ogg19880414

• 论文 • 上一篇    下一篇

根据沉积历史分析华南古大陆边缘的构造演化

段太忠1, 曾允孚2, 高振中1   

  1. 1. 江汉石油学院;
    2. 成都地质学院
  • 收稿日期:1987-10-24 修回日期:1988-03-04 出版日期:1988-12-25 发布日期:2012-01-16

ANALYSIS OF TECTONIC EVOLUTION OF PALEO-CONTINENTAL MARGIN IN SOUTH CHINA

Duan Taizhong1, Zeng Yunfu2, Gao Zhenzhong1   

  1. 1. Jianghan College of Petroleum;
    2. Chengdu College of Geology
  • Received:1987-10-24 Revised:1988-03-04 Online:1988-12-25 Published:2012-01-16

摘要:

沉积历史的分析表明,华南古大陆边缘带经历了三个阶段的板块构造演化:裂谷作用阶段(?一Z1)以发育北东向地堑地垒为特征.被动大陆边缘阶段(Z2—O1)主要是稳定下沉与沉积充填作用;陆架边缘随时间发生大规模向海推进;大陆边缘沉积特征从早期至晚期渐趋规则、统一.闭合造山阶段(O2—S)前期大陆边缘急剧下沉,台地变为深水盆地;晚期接受来自与前期物源完全相反方向的大量粗碎屑物质,以至最终隆起成山.

Abstract:

The analysis of sedimentary history indicates that, paleocontinental mar-gin in South China underwent multistage plate tectonic evolution of rift, pas-sive margin and clousure orogeny from Late Presinian to Silurian. A series of grabens stretching NE developed during the rift stage(Presinian-Early Sinian). they were filled with a series of coarse clastic rocksmainly by gravity flow and intercalated beds of basaltic volcanic breccia whichbelongs to A- series or T-series on the diagram of Na2O+K2O versus SiO2and tuff. Isolated carbonate platforms and ambient deeper-water basins weredeveloped inside the young passive margin(Middle Sinian-middle Early Camb-riam), and then sedimentary filling made it an extensive shallow-water car-bonate platform: deep-water starved basins appeared rapidly after the rifting. In the outer side of the young passive margin, only silicalite of tens ofmeters thick was developed. Matured passive Margin(late Early Cambrian-Early Ordovician) was characterized by the development of a huge carbona-te wedge along the shelf break zone. In the outer shelf and shelf margin,algal reefs and carbonate banks usually developed well: the associationof slope and slope-toe was dominated by various kinds of gravity flow se-diments in the early stage and was characterized by contourites in the latestage; pelagic laminated marls and shales developed in the basin. Ano-ther important character was that the shelf margin migrated towards sea,leading to distictive prograding sedimentation on the slope. During theclousure orogeny stage of the Middle Ordovician-Silurian, the direction ofsediment transportation changed opposite, and coarse clastics prograded pro-gressively from southeast to northwest even overlapped onto the central partof the paleo-Yangzi Plate. This process formed a shallowing-upward se-quence which composed of a thick clastic rock that changed from turbidites inbottom to coastal sediments in top till continental deposits. This orogenyfinally ended up with the widespread uplift in the end of the Silurian.