SAN CLEMENTE ISLAND ROCKSITE PROJECT: OFFSHORE GEOLOGY. PART I. DETAILED SURVEY OFF EEL AND LOST POINTS AREA,
Abstract
Two nearshore geophysical and geological surveys for the Rocksite Project off San Clemente Island, California, were made using continuous seismic profiling systems, geological diving, snapper sampling, and the CURV vehicle. Geologic interpretations are made relative to one of the surveys, a detailed survey off part of the west side of the island. A sequence of four sediment and rock units (A through D) is defined on the basis of the acoustical character and geometry of the acoustic reflection records. A north to northeast structural trend similar to that on the adjacent part of the island is mapped offshore. Some seaward pivotal faulting, not apparent from the island study, is suggested and appears partly responsible for the development of a submarine canyon located off Eel Point. Isopach maps of Units A, B, and C, and a structure contour map of Unit D tend to confirm this structural trend. A major unconformity is noted between Units B and C. A major insular terrace, at slightly over 100 meters in depth and prominent on the west side of the island, is postulated to have been wave-cut during Late Pleistocene to Recent time. This terrace has been affected by Recent tectonism. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1968
- Accession Number
- AD0830816
Entities
People
- J. B. Ridlon
Organizations
- Naval Air Weapons Station China Lake