SUBSIDENCE OF SAN-FRANCISCO BAY - BLAME IT ON SALINIA

The San Francisco Bay basin in central coastal California has formed i n response to the capture by and emplacement onto the Pacific plate of the Salinian terrane during the past 4 m.y. The addition of mass (the Salinian terrane) onto the Pacific plate caused the flexural downwarp of the Pacific plate and the formation and subsidence of the San Fran cisco Bay basin. As a result of continued plate-boundary evolution, se dimentary basins that previously formed in this way along the San Andr eas fault may be ephemeral. Much of the basin may be removed during cr ustal capture by the Pacific plate and translation through Santa Cruz Mountain-like fault geometries. Remnants of such flexural downwarp bas ins may be preserved within the nearshore basins on the Pacific plate.