Examining the timing of Shallow-Angle Subduction of the Farallon Plate in the Western United States: Zircon U-Pb Geochronology of the Schist of Sierra de Salinas

Authors

Kendall A. Ford, Macalester CollegeFollow

Document Type

Honors Project On-Campus Access Only

Abstract

The schist of Sierra de Salinas (central California) is a metasandstone originating from accretionary wedge materials accumulated along the North America-Farallon plate boundary. The schist‘s protolith was subducted and metamorphosed during a shallow-angle subduction episode of the Farallon Plate. Ion microprobe analysis of zircons from a sample collected from a high-grade portion of the schist of Sierra de Salinas yields a weighted mean age of 78.2 +/- 0.8 Ma (1σ). This age likely reflects the timing of the schist’s metamorphism, corroborating earlier work indicating that metamorphism took place within a 81-72 Ma window.

Recommended Citation

Ford, Kendall A., "Examining the timing of Shallow-Angle Subduction of the Farallon Plate in the Western United States: Zircon U-Pb Geochronology of the Schist of Sierra de Salinas" (2021). Geology Honors Projects. 23.
https://digitalcommons.macalester.edu/geology_honors/23