Exploration Potential of Offshore Newport-Inglewood Fault Zone

James K. Crouch, Steven B. Bachman

Marine seismic-reflection profiles and offshore coreholes delineate the structure and stratigraphy along the offshore extension of the Newport-Inglewood fault zone between Newport Beach and Oceanside, California. Offshore, the zone consists of a linear trend of faulted anticlines that are similar in size and character to the highly productive well-known structures along the Newport-Inglewood trend of the Los Angeles basin. Anticlinal traps along the onshore Newport-Inglewood trend have yielded more than 2.5 billion bbl of oil from upper Miocene and lower Pliocene deep-water turbidite sand reservoirs. Because the direct offshore extension of this trend contains comparable stratigraphy and structure, similar petroleum reserves can be expected offshore.

Wrench-related fold and flower structures, as well as thrust-related structures, can be recognized offshore. The wrench-related structures occupy a 2 to 3-mi wide zone directly along the offshore Newport-Inglewood fault zone, which extends along the outer shelf between Dana Point and Oceanside. The thrust-related structures, however, form parallel to, and seaward of, the offshore Newport-Inglewood fault zone and appear to be related to fault-normal compressional forces.

AAPG Search and Discovery Article #91024©1989 AAPG Pacific Section, May 10-12, 1989, Palm Springs, California.