Faulting and Folding of the Transgressive Surface Offshore Ventura Records Deformational Events in the Holocene

Identifying the offshore thrust faults of Western Transverse Ranges that could produce large earthquakes and seafloor uplift is essential to assess potential geohazards for region. The in southern California are an E-W trending fold-and-thrust system extends west Ventura. Using a high-resolution seismic CHIRP dataset, we have identified Last Glacial Transgressive Surface (LGTS) two Holocene seismostratigraphic units. Deformation LGTS, together with onlapping packages exhibit divergence rotation across active structures, provide evidence three four deformational events vertical uplifts ranging from 1 10 m. Based on depth LGTS sediment thickness, age estimates reveal good correlation onshore paleoseismological results Ventura-Pitas Point fault Ventura-Avenue anticline. observed deformation along segments anticline trend diminishes toward west. Farther north, Red Mountain also shortening stepping north onto Mesa-Rincon Creek system. These observations suggest fault-fold structures moving westward systematically hinterland. decrease amount frontal towards corresponds increase hinterland fold systems, which result connection strands at depth. A northward dipping thrusts regional master detachment may explain apparent jump west, anticline, then, Finally, considering maximum estimated these (max ∼10 m), common rupture concert, this generate magnitude earthquake (>Mw 7.0) consequent tsunami.