The Bermuda hotspot is a supposed midplate hotspot swell in the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

southeast of

Bermuda ) , anthem = "God Save the King" , song_type = National song , song = " Hail to Bermuda" , image_map = , map_caption = , image_map2 = , mapsize2 = , map_caption2 = , subdivision_type = Sovereign state , subdivision_name = , e ...

, proposed to explain the extinct volcanoes of the

Bermuda Rise ) , anthem = "God Save the King" , song_type = National song , song = "Hail to Bermuda" , image_map = , map_caption = , image_map2 = , mapsize2 = , map_caption2 = , subdivision_type = Sovereign state , subdivision_name = , es ...

as well as the

Mississippi Embayment The Mississippi embayment is a physiographic feature in the south-central United States, part of the Mississippi Alluvial Plain. It is essentially a northward continuation of the fluvial sediments of the Mississippi River Delta to its conflu ...

and the Sabine Uplift southwest of the Mississippi Embayment. A 2002 paper proposes that the Bermuda hotspot generated the Mississippi Embayment in the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

period, 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 Trough may refer to: In science * Trough (geology), a long depression less steep than a trench * Trough (meteorology), an elongated region of low atmospheric pressure * Trough (physics), the lowest point on a wave * Trough level (medicine), the l ...

. The seismic zones centered on

New Madrid, Missouri New Madrid ( es, Nueva Madrid) is a city in New Madrid County, Missouri, United States. The population was 2,787 at the 2020 census. New Madrid is the county seat of New Madrid County. The city is located 42 miles (68 km) southwest of Cairo ...

, and

Charleston, South Carolina Charleston is the largest city in the U.S. state of South Carolina, the county seat of Charleston County, and the principal city in the Charleston–North Charleston metropolitan area. The city lies just south of the geographical midpoint o ...

, and the volcanic

kimberlite Kimberlite is an igneous rock and a rare variant of peridotite. It is most commonly known to be the main host matrix for diamonds. It is named after the town of Kimberley in South Africa, where the discovery of an diamond called the Star of ...

pipes in

Arkansas Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the Osage ...

are cited as evidence. Other published reports 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 alternatively attribute the Bermuda Rise to a reorganization of plate tectonics associated with the closing of the

Tethys Sea The Tethys Ocean ( el, Τηθύς ''Tēthús''), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean that covered most of the Earth during much of the Mesozoic Era and early Cenozoic Era, located between the ancient continents ...

, though noting that shallow processes may not explain the source of the magmatism. A more recent paper finds a thinning in the

mantle transition zone The transition zone is part of the Earth's mantle, and is located between the lower mantle and the upper mantle, between a depth of 410 and 660 km (250 to 400 mi). The Earth's mantle, including the transition zone, consists primarily o ...

under Bermuda, apparently consistent with mantle upwelling and a hot lower mantle below Bermuda. A still more recent paper, based on geochemical analysis of a drill core, suggests that Bermuda volcanism sampled a transient mantle reservoir in the

that was formed by chemical recycling related to subduction during the formation of

Pangaea Pangaea or Pangea () was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million y ...

References

Hotspots of the Atlantic Ocean Hotspots of North America Geology of Bermuda {{Bermuda-geo-stub

See also

References