ABSTRACT This guide begins with an overview of the internal structure and petrology of the Catalina Schist terrane as exposed on Santa Catalina Island, California, followed by a discussion of the tectonic setting and exhumational history of the terrane, and the Cenozoic tectonic and geological evolution of the Inner Borderland, within which it lies. The guide then presents an itinerary for a three-day field trip from 9–11 May 2020. Next, we present a tectonic model for the formation of the Catalina Schist, followed by a discussion of its relationship to the Pelona, Orocopia, Rand, and related schists in southern California.

ABSTRACT Conglomerate-clast analysis, sandstone petrology, and detrital zircon age data determine the provenance and correlation of the Middle Miocene Mint Canyon and Caliente Formations. Detrital zircon age assemblages and sandstone compositions confirm that the Mint Canyon Formation is the upstream equivalent of the southern Caliente Formation and that both are dissimilar to the Punchbowl Formation. The Mint Canyon and Caliente Formations are remnants of an axial drainage system that was likely confined by the ancestral Sierra Pelona/Blue Ridge to the north and ancestral San Gabriel Mountains to the south; sediments derived from these local highlands dominate in the Mint Canyon Formation. This study highlights the importance of integrated-methods analysis. Sandstone detrital modes capture the variability in sandstone composition and the degree of overlap between formations; conglomerate-clast compositional data show differences within the drainage system; distinct detrital zircon age assemblages implicate particular source terranes. Analysis of all these data sets provides a robust and complete characterization of the provenance of this confined drainage system.