Middle Tertiary volcanism during ridge-trench interactions in western California

Journal Article · Thu Oct 01 04:00:00 EDT 1992 · Science (Washington, D.C.); (United States)

DOI:https://doi.org/10.1126/science.258.5083.793· OSTI ID:6994683

Cole, R B; Basu, A R ^[1]

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1. 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), Journal Name: Science (Washington, D.C.); (United States) Vol. 258:5083; ISSN SCIEAS; ISSN 0036-8075
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CALIFORNIA
CENOZOIC ERA
DEVELOPED COUNTRIES
EARTH MANTLE
GEOLOGIC AGES
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
NORTH AMERICA
PLATE TECTONICS
TECTONICS
TERTIARY PERIOD
USA
VOLCANISM
VOLCANOES