HR: 1340h
AN: OS53A-0975 [Abstracts]
TI: The crustal structure of South China Sea continental slope
AU: * Jen, Z
EM: leecs@mail.ntou.edu.tw
AF: Institute of Applied Geosciences, National Taiwan Ocean University, 2 Pei-Ning Road,
Keelung, 202, Taiwan
AU: Wang, T
EM: tkwang@mail.ntou.edu.tw
AF: Institute of Applied Geosciences, National Taiwan Ocean University, 2 Pei-Ning Road,
Keelung, 202, Taiwan
AU: Lee, C
EM: leecs@mail.ntou.edu.tw
AF: Institute of Applied Geosciences, National Taiwan Ocean University, 2 Pei-Ning Road,
Keelung, 202, Taiwan
AB:
The sea-floor spreading of the South China Sea (SCS) was stopped since Miocene; this probably means that the
plate tectonics in the SCS is in a stable situation. According to the magnetic anomaly, the sea-floor spreading of
SCS was started in Oligocene and stopped in Miocene, and the continental rifting probably happened around
Mesozoic. There are many differences between the northern and the southern sides of SCS. As we can see in the
SCS regional map; the northern side is the continental shelf covered by thick sediments; and the southern side
are numerous coral reef islands, the Spratly islands, covered up to 2-3 km thick of carbonates. Based on the
seismic profiles, it shows a serial of normal faults in the northern side, and in the southern side are normal faults
and thrust faults with different slip directions. The southern side has also a long history related to the formation of
the reef islands. It probably means that the early continental rifting of the SCS is the passive Atlantic type shear
processes.
During 8/20 ¡V 9/11, 2007, we have conducted a two-ship MCS/OBS study in the northern continental slope of the
SCS. Previously, the area had been surveyed by a China-Japan OBS study in 1983, the US Columbia University
for an ESP study in 1985, a China-German OBH study in 1996, and a Taiwan-China MCS/OBS study in 2001. All
are aiming to better understand the crustal structure of the SCS continental shelf.
DE: 4200 OCEANOGRAPHY: GENERAL
DE: 4219 Continental shelf and slope processes (3002)
DE: 4243 Marginal and semi-enclosed seas
DE: 8110 Continental tectonics: general (0905)
DE: 8169 Sedimentary basin processes
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting