Geologic Publications for Mount Rainier

Pathway from subducting slab to surface for melt and fluids beneath Mount Rainier

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Author(s): R S. McGary, Rob L. Evans, Philip E. Wannamaker, Jimmy Elsenbeck, Stephane Rodenay

Category: PUBLICATION
Document Type:
Publisher: Nature
Published Year: 2014
Volume: 511
Number:
Pages: 338 to 340
DOI Identifier: 10.1038/nature13493
ISBN Identifier:
Keywords: geophysics tectonics

Abstract:
Convergent margin volcanism originates with partial melting, primarily of the upper mantle, into which the subducting slab descends. Melting of this material can occur in one of two ways. The flow induced in the mantle by the slab can result in upwelling and melting through adiabatic decompression. Alternatively, fluids released from the descending slab through dehydration reactions can migrate into the hot mantle wedge, inducing melting by lowering the solidus temperature. The two mechanisms are not mutually exclusive1. In either case, the buoyant melts make their way towards the surface to reside in the crust or to be extruded as lava. Here we use magnetotelluric data collected across the central state of Washington, USA, to image the complete pathway for the fluid–melt phase. By incorporating constraints from a collocated seismic study into the magnetotelluric inversion process, we obtain superior constraints on the fluids and melt in a subduction setting. Specifically, we are able to identify and connect fluid release at or near the top of the slab, migration of fluids into the overlying mantle wedge, melting in the wedge, and transport of the melt/fluid phase to a reservoir in the crust beneath Mt Rainier.

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In Text Citation:
McGary and others (2014) or (McGary et al., 2014)

References Citation:
McGary, R.S., R.L. Evans, P.E. Wannamaker, J. Elsenbeck, and S. Rodenay, 2014, Pathway from subducting slab to surface for melt and fluids beneath Mount Rainier: Nature, Vol. 511, pp. 338-340, doi: 10.1038/nature13493.