Phanerozoic Tectonic Evolution of Central California and Environs

Abstract

The use of actualistic analog models for paleotectonic reconstruction produces significant advances in our understanding of evolutionary continental tectonics. The sequential application of such models is possible in a cross section from the central California coast to Utah. This transect represents one of the best-understood Phanerozoic continental margins on Earth. Excellent exposure, detailed local studies, and regional syntheses all contribute to the choice of appropriate plate-tectonic models for successive intervals from the latest Neoproterozoic to the Quaternary. These models include craton, terrestrial rift, nascent ocean, intraplate continental margin, intraoceanic magmatic arc intraplate margin, Devonian-Mississippian Antler orogeny (arc-continent suturing), Mississippian-Pennsylvanian intraplate margin, Pennsylvanian-Permian Ancestral Rockies orogeny (Ouachita-Marathon continental suturing), Permian-Triassic Sonoma orogeny (arc-continent suturing), Triassic-Jurassic continental-margin magmatic arc, Late Jurassic Nevadan orogeny (arc-arc suturing), latest Jurassic-Late Cretaceous continental-margin magmatic arc, latest Cretaceous-Eocene Laramide orogeny, Oligocene ignimbrite flare-up, and Miocene-Holocene triple-junction migration, transform boundary, and regional extension of the Great Basin. The integrated result of sequential superposition of the actualistic models produces a reasonable representation of the complexity of the study area. The discipline of applying actualistic models to the evolution of this continental margin provides new insights and forces one to consider new implications of the models. The complexity of the tectonic history of this continental margin argues against simplistic general models for the growth of continental crust.