Abstract: Comparative Analysis of Three Pull-Apart Basins: Los Angeles Basin, Onshore California, Tanner Basin, Offshore California, and Cariaco Basin, Offshore Venezuela

B. Blanco

Basins that are of pull-apart origin evolve between overstepping strike-slip faults and tend to be small and narrow (less than about 50 km wide). In this paper we review the geometry, stratigraphy, structural features, and tectonic history of three basins whose origin as pull-apart basins has been well-established: the Cariaco Basin, offshore Venezuela; the Tanner Basin, offshore California; and the Los Angeles Basin, onshore California.

Los Angeles, Tanner, and Cariaco basins have in common not just being located at a continental borderland margin, an area characterized by a ridge-basin morphology, but also they offer many other similarities, such as tectonic setting, age and tectonic evolution. The three basins are Neogene basins formed by extension associated with strike-slip within evolving transform systems. Los Angeles and Tanner basins were formed within the San Andreas transform system, where interaction between the North American and Pacific plates is occurring. The Cariaco basin was formed within the San Sebastian-El Pilar fault system, where interaction between the Caribbean and South American plates exists. Also, the three basins are located within continental margins that have had a similar tectonic evolu ion: a subduction margin that changed to a transform margin where transpression with local extension is occurring.

AAPG Search and Discovery Article #90951©1996 AAPG International Conference and Exhibition, Caracas, Venezuela