Long-term Tectonic Control on Holocene Shelf Sedimentation Offshore La Jolla, California

Authors Leah J. Hogarth, SIO/UCSD, lhogarth -@- ucsd.edu Jeffrey Babcock, IGPP/SIO/UCSD, jbabcock -@- ucsd.edu Neal W. Driscoll, SIO/UCSD, ndriscoll -@- ucsd.edu Nicolas Le Dantec, SIO/UCSD, nledante -@- ucsd.edu Jennifer K. Haas, SIO/UCSD, jhaas -@- ucsd.edu Douglas L. Inman, SIO/UCSD, dinman -@- ucsd.edu Patricia M. Masters, SIO/UCSD, pmasters -@- ucsd.edu Project Description A high-resolution CHIRP survey reveals shore-parallel variations in the Holocene sediment thickness offshore La Jolla, California. Sediment thicknesses decrease from greater than 20 m in the south near Scripps Canyon to zero in the north approaching Torrey Pines. In addition to the south to north variation in sediment thickness, the transgressive surface observed in seismic lines shoals from Scripps Canyon to the north. Despite these dramatic shore-parallel subsurface changes, the nearshore bathymetry exhibits little to no change along strike. A left jog (i.e., a constraining bend) along the Rose Canyon Fault causes local uplift in the region and appears to explain the northward shoaling of the transgressive surface, the decrease in relief on the transgressive surface away from the left jog, and the Holocene sediment thickness variation. This tectonic deformation is shore parallel, and thus the accommodation can be separated into its tectonic and eustatic components. Download the Full Paper Hogarth et al., 2006 [Coming Soon...!]