image: The break in slope is coincident with a discontinuity representing a regional three- to five-million-year hiatus separating two distinct styles of volcanic activity in the Cascadia backarc region. The lower slope is composed of high-K calc-alkaline lavas derived from melting of a hydrated mantle source from 30 to 20 Ma. The steeper upper slope is composed of thin flows of the tholeiitic Steens Basalt (early lavas of the Columbia River Basalt Group) derived from melting of a dry mantle source with a plume component at ca. 17 Ma. view more
Credit: Victor Camp and Ray Wells
Boulder, Colo., USA: The Yellowstone hotspot is well known for generating supereruptions in the geologic past that are far more explosive than historic examples. The origin and sustained longevity of the hotspot is less understood but is focused on two competing models, where the ascent of hot mantle is derived from either a deep-seated mantle plume or a shallow mantle source.
In their study published this month in GSA Today, Vic Camp and Ray Wells use an integrated database that supports the idea of a deep mantle-plume origin for the Yellowstone hotspot with a robust history of magmatism that extends to at least 56 million years ago, far older than previously thought. In this scenario, hotspot volcanism began offshore and migrated to the east-northeast across northeastern California, northern Nevada, southeastern Oregon, and southern Idaho to its current position at Yellowstone National Park.
This long-lived path of hotspot migration is marked by a belt of aligned volcanic provinces that display progressively younger ages to the east-northeast, similar to the age progression produced by southwest motion of the North America plate over a fixed Yellowstone hotspot.
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ARTICLE
The Case for a Long-Lived and Robust Yellowstone Hotspot
https://www.geosociety.org/GSA/Publications/GSA_Today/GSA/GSAToday/science/G477A/article.aspx
Victor E. Camp,
San Diego State University,
Dept. of Geological Sciences,
5500 Campanile Drive, San Diego, California 92182, USA,
vcamp@sdsu.edu
Ray E. Wells,
U.S. Geological Survey,
2130 SW 5th Street, Portland, Oregon 97201, USA
GSA Today articles are open access online; for a print copy, please contact Kea Giles. Please discuss articles of interest with the authors before publishing stories on their work, and please make reference to GSA Today in articles published.
Journal
GSA Today