Английская Википедия:Bermuda hotspot

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Шаблон:Short description Шаблон:Use dmy dates The Bermuda hotspot is a supposed midplate hotspot swell in the Atlantic Ocean Шаблон:Convert southeast of Bermuda,[1] proposed to explain the extinct volcanoes of the Bermuda Rise as well as the Mississippi Embayment[2][3][4] and the Sabine Uplift southwest of the Mississippi Embayment.[5]

A 2002 paper proposes that the Bermuda hotspot generated the Mississippi Embayment in the Early Cretaceous Epoch, when the hotspot strengthened and uplifted the present-day Mississippi Valley. The resulting highland eroded over time, and when North American plate motion moved the valley away from the hotspot, the resulting thinned lithosphere subsided, forming a trough. The seismic zones centered on New Madrid, Missouri, and Charleston, South Carolina, and the volcanic kimberlite pipes in Arkansas are cited as evidence.[4]

Other published reports[6][7] argue that the lack of a chain of age-progressive seamounts (as in the Hawaiian-Emperor seamount chain), the absence of present-day volcanism, and the elongation of the Bermuda Rise oblique to plate motion are evidence against a hotspot origin for the Bermuda Rise. Others[6] alternatively attribute the Bermuda Rise to a reorganization of plate tectonics associated with the closing of the Tethys Sea, though noting that shallow processes may not explain the source of the magmatism. A more recent paper[7] finds a thinning in the mantle transition zone under Bermuda, apparently consistent with mantle upwelling and a hot lower mantle below Bermuda. A still more recent paper,[8] based on geochemical analysis of a drill core, suggests that Bermuda volcanism sampled a transient mantle reservoir in the mantle transition zone that was formed by chemical recycling related to subduction during the formation of Pangaea.

See also

References

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Шаблон:Bermuda-geo-stub