Structure of Cuyama Valley, Caliente Range, and Carrizo
Plain, and Its Significance to Structural
Style of Southern Coast Ranges and
Western Transverse Ranges
T. L. Davis, W. J. M. Bazeley, S. Gordon, M. B. Lagoe, K. D. McIntosh, J. S. Namson
A concerted exploration program in the Cuyama area by ARCO during the last 10
years, employing surface mapping, deep drilling, high-quality seismic profiles,
biostratigraphic analysis, and balanced cross
sections
, has revealed several
significant
structural
characteristics. (1) Thrust faults, such as the Morales
and White Rock, flatten under the Caliente Range and merge into a single system
with up to 14 km of slip. This system intersects the San Andreas fault at a high
angle and may detach the San Andreas fault at depth from 7 to 8 km. (2)
Integration of surface and subsurface mapping shows that these thrust faults
have little or no component of strike-slip and are younger than 3 Ma. (3) Major
surface folds, such as the Caliente Mountain anticline, are due to thrust faul s
ramping upsection and producing fault-bend and fault-propagation folds. (4) The
young thrust system has cut across a late Oligocene to early Miocene extensional
fault-controlled basin, and both tectonically transported and overthrust
portions of this older basin. These
structural
characteristics strongly suggest
that the
structural
style of the Cuyama area and possibly adjacent areas in the
southern Coast Ranges and western Transverse Ranges is that of a fold-and-thrust
belt and is not related to wrench tectonics.
AAPG Search and Discovery Article #91035©1988 AAPG-SEPM-SEG Pacific Sections
and SPWLA Annual Convention, Santa Barbara, California, 17-19 April 1988.