Composition of Modern Sand from the Sierra Nevada, California, U.S.A.: Implications for Actualistic Petrofacies of Continental-Margin Magmatic Arcs

摘要

The Sierra Nevada of California represents the roots of a long-lived magmatic arc (primarily Cretaceous) that is presently being dissected as the range is uplifted, beginning in the south and progressing northward. This dissection is occurring concurrently with northward migration of the Mendocino triple junction, south of which magmatic-arc activity is absent, and north of which magmatic-arc activity continues. A north-to-south transect along the Sierra Nevada represents transitions of active magmatic arc to transitional arc to dissected arc, and in the southern Sierra Nevada, to uplifted basement. Thus, analysis of composition of modern sand derived from these separate parts of the Sierra Nevada provides a test for actualistic sand(stone) petrofacies of magmatic arcs at all stages of dissection.