Melting under the Colorado Plateau, USA

Mary R. Reid, Romain A. Bouchet, Janne Blichert-Toft, Alan Levander, Kaijian Liu, Meghan S. Miller, Frank C. Ramos

Research output: Contribution to journalArticle

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Abstract

Mafic volcanism gradually encroaching on the tectonically stable Colorado Plateau in the southwestern United States appears to originate from within Paleoproterozoic lithosphere. New Hf and Nd isotope data strengthen evidence for magma source heterogeneity; other geochemical signatures show these sources to consist dominantly of peridotite. Tomographic and receiver function analyses reveal that young volcanism occurs above or outboard of a pronounced shallowing in the lithosphere-asthenosphere boundary. Melt extraction extends to the base of lithosphere thinned to <75 km, with more shallowly derived melts characterized by higher degrees of partial melting. Accordingly, decompression melting of a reactivated chemical boundary layer ± asthenosphere, rather than in situ lithospheric melting or melting of lithospheric mantle drips/delaminations, appears to be responsible for recent Colorado Plateau magma generation.

Original languageEnglish (US)
Pages (from-to)387-390
Number of pages4
JournalGeology
Volume40
Issue number5
DOIs
StatePublished - May 1 2012

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ASJC Scopus subject areas

  • Geology

Cite this

Reid, M. R., Bouchet, R. A., Blichert-Toft, J., Levander, A., Liu, K., Miller, M. S., & Ramos, F. C. (2012). Melting under the Colorado Plateau, USA. Geology, 40(5), 387-390. https://doi.org/10.1130/G32619.1