HR: 1340h
AN: S23A-1118    [Abstracts]
TI: Tectonic controls on sedimentation in the Eel River Basin: high-resolution CHIRP seismic data
AU: * Hogarth, L J
EM: lhogarth@ucsd.edu
AF: Scripps Institution of Oceanography, University of California San Diego 9500 Gilman Dr SIO 0244, La Jolla, CA 92093, United States
AU: Driscoll, N W
EM: ndriscoll@ucsd.edu
AF: Scripps Institution of Oceanography, University of California San Diego 9500 Gilman Dr SIO 0244, La Jolla, CA 92093, United States
AU: Babcock, J M
EM: jbabcock@ucsd.edu
AF: Scripps Institution of Oceanography, University of California San Diego 9500 Gilman Dr SIO 0244, La Jolla, CA 92093, United States
AB: High-resolution CHIRP seismic data reveal the details of shore-parallel variations in Late-Pleistocene and Holocene sediments along the tectonically active Eel River Basin region, offshore Northern California. Shore- perpendicular deformation due to the northward migration of the Mendocino Triple Junction creates a tectonic signal with varying sign and amplitude oriented parallel to the coastline. This geometry provides an ideal opportunity to examine how tectonic deformation affects stratigraphic architecture and facies assemblages. Sediments are thinnest over the Little Salmon Anticline and systematically thicken towards the Eel Syncline. Seismic reflectors diverge into the syncline where sedimentary sections are expanded indicating tectonic deformation has been concurrent with sedimentation since the Last Glacial Maximum (LGM ~21,000 ka). We also observe offset on the transgressive surface above the thrust fault of the Little Salmon Anticline indicating fault displacement has occurred post transgression. While previous multi-channel seismic data sets from this region have detailed variation in the arrangement of facies and associated stratal geometry over the last several million years, this high-resolution CHIRP data set provides an opportunity to observe with greater resolution the formation of strata during the most recent deformation along this active margin.
DE: 3025 Marine seismics (0935, 7294)
DE: 3045 Seafloor morphology, geology, and geophysics
SC: Seismology [S]
MN: 2007 Fall Meeting