被动大陆边缘：从大陆张裂到海底扩张

doi:10.11867/j.issn.1001-8166.2003.05.0730

地球科学进展 ›› 2003, Vol. 18 ›› Issue (5): 730 -736. doi: 10.11867/j.issn.1001-8166.2003.05.0730

被动大陆边缘：从大陆张裂到海底扩张

曹洁冰,周祖翼

同济大学海洋地质教育部重点实验室，上海 200092

收稿日期:2003-05-23 修回日期:2003-07-25 出版日期:2003-12-20
通讯作者: 曹洁冰 E-mail:jiebing_cao@yahoo.com.cn
基金资助:
国家重点基础研究发展规划项目“中国边缘海形成演化的动力学机制”（编号：G2000046704）资助.

PASSIVE MARGINS: FROM CONTINENTAL RIFTING TO OCEANIC SPREADING

Cao Jiebing, Zhou Zuyi

Laboratory of Marine Geology, Tongji University, Shanghai 200092,China

Received:2003-05-23 Revised:2003-07-25 Online:2003-12-20 Published:2003-10-01

被动边缘是研究大陆张裂、破裂到海底扩张的关键。ODP103、149、173航次对伊比利亚-纽芬兰非火山型共轭边缘的研究，证实了洋陆过渡带和低角度拆离断层的存在，其中洋陆过渡带中广泛出现蛇纹岩化地幔橄榄岩，钻探结果支持不对称单剪模式。ODP104、152、163航次对挪威-格陵兰东南火山型共轭边缘的调查，揭示了典型的向海倾斜反射层（SDRS）的特征，反映了岩浆活动在边缘形成中的主导作用。为了进一步了解大陆从张裂到破裂到洋底扩张过程的一系列学术问题，需要在IODP阶段继续对共轭被动边缘以及包括冲绳海槽和南海在内的典型地区，通过钻探、采样和观测进行更深入的研究。

关键词: 火山型被动边缘, 非火山型被动张裂, 大陆张裂, 海底扩张

Passive margin study has been at the core of scientific ocean drilling because it provide important information on processes in continental extension, breakup, and the eventual formation of new oceanic spreading centers. In this paper, ODP investigations in the evolution and characteristic of volcanic & non-volcanic passive margins have been briefly introduced. Drilling on the Iberia-Newfoundland non-volcanic margin by ODP Legs 103, 149 and 173 have demonstrated clearly that low-angle detachment faults have contributed to the unroofing and formation of continent-ocean transition zone, resulting in the exposure of serpentinized and tectonized mantle peridotite. Results from ODP Leg 104, 152 and 163 on volcanic passive margin of Norway-Greenland conjugate pair suggest that the magmatic processes have played a major role in the thinning of crust and the final breakup. Drilling results so far support an asymmetric simple shear mode for the formation of non-volcanic margins. ODP explorations also reveal characteristics of seismic seaward-dipping reflections. For a better understanding of the processes from continental extension to breakup to the final oceanic spreading, further in-depth studies are required in the IODP phase by drilling, sampling across a full rift system on conjugate margin pairs and other locations such as Okinawa Trough and the South China Sea.

Key words: Volcanic passive margin, Non-volcanic passive margin, Continental rifting, Sea floor spreading.

中图分类号:

P735
P71

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