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Yellowstone Hot Spot Shreds Ancient Pacific Ocean

Posted by Soulskill on from the tectonic-violence dept.

jamie passes along this excerpt from DiscoveryNews: "If you thought the geysers and overblown threat of a supervolcanic eruption in Yellowstone National Park were dramatic, you ain't seen nothing: deep beneath Earth's surface, the hot spot that feeds the park has torn an entire tectonic plate in half. The revelation comes from a new study (abstract) in the journal Geophysical Research Letters that peered into the mantle beneath the Pacific Northwest to see what happens when ancient ocean crust from the Pacific Ocean runs headlong into a churning plume of ultra-hot mantle material."

2 of 69 comments (clear)

  1. Flood basalts by Ol+Biscuitbarrel · · Score: 5, Interesting

    The author seems to imply that the Columbia River Basalts were generated by the mantle plume, a supposition that isn't in the paper's abstract. Far as I know the jury's still out there. Here's a pdf of a 2007 paper covering the same topic; or, if that won't open for you like it isn't for me at the moment, here's the Google Quick View version.

    1. Re:Flood basalts by khallow · · Score: 5, Interesting

      The author seems to imply that the Columbia River Basalts were generated by the mantle plume

      That seems very reasonable given that at one point the two nearly coincide in position and time (cospatial and contempory) about 16-17 million years ago. Given this new information, I think we have a variety of reasonable guesses for how a hotspot can generate both a sequence of massive basalt floods and the lesser, but still substantial volcanic activity since. First, it is possible that most of the Columbia River basalts don't come from the hotspot itself, but instead come from melting of the fragment of plate that broke off, the lighter part of the melt may well have returned to the surface along the path cut by the hotspot's plume. Or the plate may have held back a significant amount of the plume, releasing a large bubble of magma at once.

      Sure, the jury is still out, but we have an interesting model that may explain a number of mysteries of the western US such as the origin of the Columbia Plateau basalt floods, the basin and range development of the Nevada area, and the anomalous acceleration of the North American plate during this time.