San Nicolas Island, the emergent top of San Nicolas Bank, lies approximately 145 km southwest of Los Angeles in the southern California Continental Borderland. San Nicolas Bank is 35 km long and 22 km wide. An investigation and integration of core and geophysical data indicate that the San Nicolas Bank area has been affected by several tectonic events and basin depositional cycles since the Cretaceous.
The oldest exposed and near-surface rocks in the area are late Cretaceous. Flat-lying, parallel, continuous, seismic reflectors and claystone samples obtained from cores indicate that the Cretaceous is sedimentary and was deposited in a deep-water marine basin.
The Eocene rocks consist of a lower sandstone, siltstone, and claystone member and an upper siltstone, and sandstone member. Seismically the lower member is a high-amplitude, parallel, continuous interval, whereas the upper member is a low-amplitude, non-parallel, and discontinuous interval. They represent a mid or suprafan system that originated south of Lake Elsinore. (See more in text.)
Description:
Includes bibliographical references (pages 111-118)
California State University, Northridge. Department of Geological Sciences.
