Holocene volcanism of the upper McKenzie River catchment, central Oregon Cascades, USA

Geological Society of America Bulletin
By: , and 

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Abstract

To assess the complexity of eruptive activity within mafic volcanic fields, we present a detailed geologic investigation of Holocene volcanism in the upper McKenzie River catchment in the central Oregon Cascades, United States. We focus on the Sand Mountain volcanic field, which covers 76 km2 and consists of 23 vents, associated tephra deposits, and lava fields. We find that the Sand Mountain volcanic field was active for a few decades around 3 ka and involved at least 13 eruptive units. Despite the small total volume erupted (∼1 km3 dense rock equivalent [DRE]), Sand Mountain volcanic field lava geochemistry indicates that erupted magmas were derived from at least two, and likely three, different magma sources. Single units erupted from one or more vents, and field data provide evidence of both vent migration and reoccupation. Overall, our study shows that mafic volcanism was clustered in space and time, involved both explosive and effusive behavior, and tapped several magma sources. These observations provide important insights on possible future hazards from mafic volcanism in the central Oregon Cascades.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Holocene volcanism of the upper McKenzie River catchment, central Oregon Cascades, USA
Series title Geological Society of America Bulletin
DOI 10.1130/B31405.1
Volume 128
Issue 11-12
Year Published 2016
Language English
Publisher Geological Society of America
Contributing office(s) Volcano Science Center
Description 17 p.
First page 1618
Last page 1635