--> ABSTRACT: Hosgri Fault Zone, Offshore Santa Maria River to Point Arguello, California, by David Cummings and Robert A. Gaal; #91038 (2010)

Datapages, Inc.Print this page

Hosgri Fault Zone, Offshore Santa Maria River to Point Arguello, California

David Cummings, Robert A. Gaal

The Hosgri fault zone between the Santa Maria River and Point Arguello was studied using 1,280 line km of digital CDP seismic reflection and analog seismic reflection data. The fault zone is interpreted as (1) being high angle within the upper 1.5 sec two-way traveltime (approximately 2,500 m); (2) having apparent reverse displacement, east block relatively up; and (3) based on subbottom and 3.5-kHz data, not cutting apparent unconsolidated (assumed Quaternary) sediments.

The fault zone is well defined at the north end of the survey area, 12 km offshore, where it consists of two subparallel faults. Although the apparent vertical offset in this area is reasonably distinct, the amount of strikeslip displacement could not be determined from the available data because of the absence of well-defined piercing points. These two faults curve eastward near 34°40^primeN latitude and horsetail, striking onshore between 34°38^primeN and 34°40^primeN latitude. These faults may be the offshore extensions of the Lompoc-Solvang fault on the south and one of the (buried) Santa Ynez River faults on the north.

AAPG Search and Discovery Article #91038©1987 AAPG Annual Convention, Los Angeles, California, June 7-10, 1987.