Correlation of late Cenozoic tuffs in the central Coast Ranges of California by means of trace and minor-element chemistry

Abstract

Deformed late Cenozoic tuffs in the central Coast Ranges of California have been correlated by means of trace-and minorelement chemistry of volcanic glass, supported by potassium-argon dates, petrographic data, and stratigraphy. Cluster analysis of the chemical data indicates that four orders of chemical variability exist in the trace-and minor-element composition of volcanic glass. The greatest differences are between tephra of silicic and intermediate composition. Considering silicic tephra alone, the greatest differences are observed between tephra erupted in different volcanic provinces. Differences between samples of silicic tephra erupted within the same volcanic field are smaller, while the smallest differences are observed between samples of tephra from individual eruptions.