Geologic and Bathymetric Reconnaissance Overview of the San Pedro Shelf Region, Southern California

This report presents a series of maps that describe the bathymetry and late
Quaternary geology of the San Pedro shelf area as interpreted from
seismic-reflection profiles and 3.5-kHz and multibeam bathymetric data. Some
of the seismic-reflection profiles were collected with Uniboom and 120-kJ
sparker during surveys conducted by the U.S. Geological Survey (USGS) in 1973
(K-2-73-SC), 1978 (S-2-78-SC), and 1979 (S-2a-79-SC). The remaining
seismic-reflection profiles were collected in 2000 using Geopulse boomer and
minisparker during USGS cruise A-1-00-SC. The report consists of seven
oversized sheets:

1. Map of 1978 and 1979 uniboom seismic-reflection and 3.5-kHz
tracklines used to map faults and folds on San Pedro Shelf.

2. Maps of multibeam shaded bathymetric relief with faults and folds,
and bathymetric contours.

3. Isopach map of unconsolidated sediment, seismic-reflection
profile across the San Pedro shelf, seismic-reflection profile
across San Gabriel paleo-valley.

4. Seismic-reflection profiles across the Palos Verdes Fault Zone.

5. Geologic map and samples of Uniboom and 120-kJ sparker
seismic-reflection profiles used to make the map.

6. Map showing thickness of uppermost (Holocene?) sediment layer.

7. Map of San Gabriel Canyon paleo-valley and associated
drainage basins.

[Summary provided by the USGS.]