Deep Structure and Dynamics of Passive Continental Margin from Shelf to Ocean of the Northern South China Sea

To study the deep dynamic mechanism leading to the difference in rifting pattern and basin structure from shelf to oceanic basin in passive continental margin, we constructed long geological sections across the shelf, slope and oceanic basin using new seismic data. Integrated gravity-magnetic invers...

Full description

Saved in:

Bibliographic Details
Published in:	Journal of earth science (Wuhan, China) Vol. 20; no. 1; pp. 38 - 48
Main Author:	吴湘杰庞雄施和生何敏申俊张向涛胡登科
Format:	Journal Article
Language:	English
Published:	China University of Geosciences (Wuhan) China University of Geosciences (Wuhan) 01-02-2009 Springer Nature B.V
Subjects:	Basins Biogeosciences Continental margins Earth and Environmental Science Earth science Earth Sciences Geochemistry Geologic depressions Geology Geotechnical Engineering & Applied Earth Sciences Graben Marine Marine geology Ocean basins Oceans Rifting Rocks Shoals Studies Upwelling 动力学机制南海北部地壳厚度大洋盆地大陆架深层结构被动大陆边缘 South China Sea ISEW, South China Sea dynamics deep structure passive margin geophysical inversion northern South China Sea
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	To study the deep dynamic mechanism leading to the difference in rifting pattern and basin structure from shelf to oceanic basin in passive continental margin, we constructed long geological sections across the shelf, slope and oceanic basin using new seismic data. Integrated gravity-magnetic inversion and interpretation of these sections were made with the advanced dissection method. Results show that the basement composition changes from intermediate-acid intrusive rocks in the shelf to intermediate-basic rocks in the slope. The Moho surface shoals gradually from 31 km in the shelf to 22.5 km in the uplift and then 19 km in the slope and finally to 13 km in the oceanic basin. The crust thickness also decreases gradually from 30 km in the northern fault belt to 9 km in the oceanic basin. The crustal stretching factor increases from the shelf toward the oceanic basin, with the strongest extension under the sags and the oceanic basin. The intensity of mantle upwelling controlled the style of basin structures from shelf to oceanic basin. In the Zhu 1 depression on the shelf, the crust is nearly normal, the brittle and cold upper crust mainly controlled the fault development; so the combinative grabens with single symmetric graben are characteristic. In the slope, the crust thinned with a large stretching factor, affected by the mantle upwelling. The ductile deformation controlled the faults, so there developed an asymmetric complex graben in the Baiyun （白云） sag.
Bibliography:	deep structure, dynamics, passive margin, geophysical inversion, northern South China Sea. P315.6 P542 42-1788/P ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23
ISSN:	1674-487X 1867-111X
DOI:	10.1007/s12583-009-0004-5