Time-evolving surface and subsurface signatures of Quaternary volcanism in the Cascades arc

Geology
By: , and 

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Abstract

Increased resolution of data constraining topography and crustal structures provides new quantitative ways to assess province-scale surface-subsurface connections beneath volcanoes. We used a database of mapped vents to extract edifices with known epoch ages from digital elevation models (DEMs) in the Cascades arc (western North America), deriving volumes that likely represent ∼50% of total Quaternary eruptive output. Edifice volumes and spatial vent density correlate with diverse geophysical data that fingerprint magmatic influence in the upper crust. Variations in subsurface structures consistent with volcanism are common beneath Quaternary vents throughout the arc, but they are more strongly associated with younger vents. Geophysical magmatic signatures increase in the central and southern Cascade Range (Cascades), where eruptive output is largest and vents are closely spaced. Vents and correlated crustal structures, as well as temporal transitions in the degree of spatially localized versus distributed eruptions, define centers with lateral extents of ∼100 km throughout the arc, suggesting a time-evolving spatial focusing of magma ascent.

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Publication type Article
Publication Subtype Journal Article
Title Time-evolving surface and subsurface signatures of Quaternary volcanism in the Cascades arc
Series title Geology
DOI 10.1130/G47706.1
Volume 48
Issue 11
Year Published 2020
Language English
Publisher Geological Society of America
Contributing office(s) Volcano Science Center
Description 6 p.
First page 1088
Last page 1093
Country United States
State California, Oregon, Washington
Other Geospatial Cascades arc
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