HR: 0800h
AN: S31A-04    [Abstracts]
TI: Seismic Structural Setting of Western Farallon Basin, Southern Gulf of California, Mexico.
AU: * Pinero-Lajas, D
EM: dpinero@cicese.mx
AF: Division De Ciencias de la Tierra CICESE, Km 107 Carretera Tijuana-Ensenada, Ensenada, BC 22860, Mexico
AU: Gonzalez-Fernandez, A
EM: mindundi@cicese.mx
AF: Division De Ciencias de la Tierra CICESE, Km 107 Carretera Tijuana-Ensenada, Ensenada, BC 22860, Mexico
AU: Lopez-Martinez, M
EM: marlopez@cicese.mx
AF: Division De Ciencias de la Tierra CICESE, Km 107 Carretera Tijuana-Ensenada, Ensenada, BC 22860, Mexico
AU: Lonsdale, P
EM: plonsdale@ucsd.edu
AF: Scripps Institution of Oceanography, Marine Physical Laboratory UCSD, 9500 Gilman Drive, La Jolla, CA 92093, United States
AB: Data from a number of high resolution 2D multichannel seismic (MCS) lines were used to investigate the structure and stratigraphy of the western Farallon basin in the southern Gulf of California. A Generator-Injector air gun provided a clean seismic source shooting each 12 s at a velocity of 6 kts. Each signal was recorded during 6- 8 s, at a sampling interval of 1 ms, by a 600 m long digital streamer with 48 channels and a spacing of 12.5 m. The MCS system was installed aboard CICESE's (Centro de Investigacion Cientifica y de Educacion Superior de Ensenada) 28 m research vessel Francisco de Ulloa. MCS data were conventionally processed, to obtain post- stack time-migrated seismic sections. The MCS seismic sections show a very detailed image of the sub-bottom structure up to 2-3 s two-way travel time (aprox. 2 km). We present detailed images of faulting based on the high resolution and quality of these data. Our results show distributed faulting with many active and inactive faults. Our study also constrains the depth to basement near the southern Baja California eastern coast. The acoustic basement appears as a continuous feature in the western part of the study area and can be correlated with some granite outcrops located in the southern Gulf of California islands. To the East, near the center of the Farallon basin, the acoustic basement changes, it is more discontinuous, and the seismic sections show a number of diffracted waves.
DE: 3025 Marine seismics (0935, 7294)
DE: 3075 Submarine tectonics and volcanism
DE: 8105 Continental margins: divergent (1212, 8124)
DE: 8106 Continental margins: transform
DE: 8169 Sedimentary basin processes
SC: Seismology [S]
MN: 2007 Joint Assembly