HR: 1330h
AN: T42B-0289    [PDF]
TI: Tectonic Evolution of Mirs Bay Basin in Guangdong, South China
AU: * Leung, K
EM: leungkf1@graduate.hku.hk
AF: Dept. of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, 000 Hong Kong
AU: Chan, L S
EM: chanls@hkucc.hku.hk
AF: Dept. of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, 000 Hong Kong
AU: Pubellier, M
EM: pubellie@geologie.ens.fr
AF: Laboratoire de Geologie, Ecole Normale Superieure-CNRS, 24 rue Lhomond, Paris, 75231 France
AB: Comprehensive structural analysis based on extensive field mapping and LANDSAT TM imageries indicates that several coastal basins in Guangdong Province of South China, including Mirs Bay, Daya Bay and Honghai Bay, are Late Cretaceous pull-apart basins structurally controlled by the NE-trending Linhuashan Fault Zone (LHFZ). A detailed study of Mirs Bay reveals a series of NW-trending high-angle normal faults dipping eastward on the southwestern margin of the basin and a broad NNW-striking fault zone on the eastern margin. The overall basin geometry is comparable to one at the mature stage of a classical pull-apart basin. The basin intersects the 500 m-wide NE-striking Tolo Channel Fault Zone, which displays a positive flower structure probably formed during the oblique subduction of the Paleo-Kula Plate under South China. Detailed study reveals a right-lateral motion postdating an earlier ductile deformation with a sinistral sense of motion along the fault zone. A southward facing thrust sheet exposed at the southern margin of the basin probably represents a detachment that formed during the collapse of the volcanic arc. Analysis of satellite images shows that the two basins located east of Mirs Bay are comparable to ones in the transitional stage of the pull-apart basin model. These three left-stepping basins are evidence for the predominantly strike-slip nature of the LHFZ during the subduction event, which has probably experienced several changes in the sense of motion during the Late Cretaceous through Tertiary in response to changes in the geodynamic setting of the surrounding blocks. (Support from HKU and PROCORE programme is gratefully acknowledged.)
DE: 8105 Continental margins and sedimentary basins
DE: 8107 Continental neotectonics
DE: 8109 Continental tectonics--extensional (0905)
DE: 8110 Continental tectonics--general (0905)
DE: 8157 Plate motions--past (3040)
SC: Tectonophysics [T]
MN: 2003 Fall Meeting