Publication Date:
2011-03-20
Description:
Most of Earth's volcanism occurs at plate boundaries, in association with subduction or rifting. A few high-volume volcanic fields are observed both at plate boundaries and within plates, fed by plumes upwelling from the deep mantle. The remaining volcanism is observed away from plate boundaries. It is typically basaltic, effusive and low volume, occurring within continental interiors2-7 or creating seamounts on the ocean floor8-11. This intraplate volcanism has been attributed to various localized processes12 such as cracking of the lithosphere8,13,14, small-scale convection in the mantle beneath the lithosphere15-17 or shear-induced melting of low-viscosity pockets of asthenospheric mantle that have become embedded along the base of the lithosphere18. Here we compare the locations of observed intraplate volcanism with global patterns of mantle flow from a numerical model. We find a correlation between recent continental and oceanic intraplate volcanism and areas of the asthenosphere that are experiencing rapid shear due to mantle convection. We detect particularly high correlations in the interior of the continents of western North America, eastern Australia, southern Europe and Antarctica, as well as west of the East Pacific Rise in the Pacific Ocean. We conclude that intraplate volcanism associated with mantle convection is best explained by melting caused by shear flow within the asthenosphere, whereas other localized processes area less important. © 2011 Macmillan Publishers Limited. All rights reserved.
Print ISSN:
1752-0894
Electronic ISSN:
1752-0908
Topics:
Geosciences
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