Middle Tertiary volcanism during ridge-trench interactions in western California
- Rochester Univ., NY (United States)
Bimodal volcanism in the Santa Maria Province of west-central California occurred when segments of the East Pacific Rise interacted with a subduction zone along the California margin during the Early Miocene (about 17 million years ago). Isotopic compositions of neodymium and strontium as well as trace-element data indicate that these volcanic rocks were derived from a depleted-mantle (mid-ocean ridge basalt) source. After ridge-trench interactions, the depleted-mantle reservoir was juxtaposed beneath the continental margin and was erupted to form basalts. It also assimilated and partially melted local Jurassic-Cretaceous sedimentary and metasedimentary basement rocks to form rhyolites and dacites. 28 refs.
- OSTI ID:
- 6994683
- Journal Information:
- Science (Washington, D.C.); (United States), Vol. 258:5083; ISSN 0036-8075
- Country of Publication:
- United States
- Language:
- English
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