San Clemente Island Rocksite Project: Offshore Geology. Part 2. Reconnaissance Survey Around the Island
Abstract
Interpretations from a nearshore geophysical and geological survey off San Clemente Island, Calif., are presented. Bathymetry around the island block is shown to differ from that of published charts. Extensive offshore faulting relates partially to that which occurs on the island. Differentiation of a major pre-orogenic surface from the post-orogenic sedimentation is shown. A steep magnetic gradient off the east side is considered the consequence of (1) volcanic flow, (2) a possible deep basic mass related to a large positive anomaly off the northwest side of the island, and (3) major faulting. Anomalous magnetic trends also reflect some of the major structural and outcrop trends. Earthquake epicenter analyses suggest less seismic activity than the adjacent land area, a tendency to quiescence at present, and an association of recent fault activity with recent epicenters. The post-orogenic sediments, believed to have followed certain major transportation channels from the island block by means of turbidity currents, sand flows, and slides, have been deposited in basin lows developed by faulting and folding.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1969
- Accession Number
- AD0859983
Entities
People
- J. B. Ridlon