UC San Diego

High-resolution CHIRP and multi-channel seismic data paired with sediment cores pro- vide an unprecedented view of forcing functions on continental margin deposits. Serving as reservoirs for hydrocarbons, sand, and aquifers, continental margin deposits have societal and scientific relevance. Traditionally, relative sea-level and sediment supply are considered the dominant controls on the geometry of continental shelf deposits. On active margins studied in this dissertation, tectonic deformation plays a large role in controlling shelf geometry, as deformation is at high angles to the shoreline. Sediment storage and dispersal are modified further by energetic oceanographic currents and climate. In the Gulf of Papua (GoP), clinothem architecture and surfaces of lap are not dependent on eustatic sea level changes. As a result of foreland basin tectonics, subsidence in the northeast GoP engenders aggradational Holocene clinoforms whereas peripheral bulge uplift in the southwest GoP causes toplap. Along-margin currents build the clinothem obliquely to the northeast. Downcore clay mineralogy constrain contributions of the Fly and Purari rivers to the GoP clinothem and lowstand deep-water basin deposits. Results suggest that sediment source and routing changed through a sea level cycle. Fly River sediment may have bypassed the inner mid-shelf clinothem during intermediate lowstands due to narrower shelf widths that allow for the establishment of incised valleys. Depocenters of post-glacial shelf deposits offshore of the Oceano Dunes State Vehicular Reservation in Central California are influenced by eustatic sea-level changes in the cross-shore direction and uplift of the San Luis Block and subsidence of the Santa Maria Basin in the along-margin direction. The timing and emplacement of turbidite deposits from submarine canyon systems offshore of San Onofre (SO) and Dana Point (DP) may be controlled primarily by shelf width. Wide shelves offshore of SO were formed by transpression along the right-lateral Newport-Inglewood/Rose Canyon Fault Zone. Turbidites offshore of SO were deposited during and prior to the last sea-level lowstand, whereas turbidites were deposited offshore DP through the sea-level transgression and highstand. Second-order controls on local turbidite emplacement include small synclines and anticlines that engender deposition or promote sediment bypass.