Bermuda hotspot
Encyclopedia
The Bermuda hotspot is the supposed "hotspot
"
(or mantle plume) proposed to explain the Bermuda Rise (a cluster of extinct volcanoes
in the Atlantic Ocean
, including the island of Bermuda
), and also
invoked by Cox and Van Arsdale to explain the origin of the Mississippi Embayment
and by Nunn to explain the Sabine Uplift (southwest of the Mississippi Embayment).
A hotspot origin for the Bermuda Rise has never been strongly supported, and has been largely shut out by a detailed and tightly argued paper by Vogt and Jung.
(See also shorter article at MantlePlumes.org
)
Evidence cited against a hotspot origin include:
1) Lack of a chain of age-progressive seamounts, such as with the
Hawaiian-Emperor
or
Great Meteor
seamount chains.
2) Elongation of the Bermuda Rise at a right angle to the direction of plate motion.
3) Various problems with the ages of igneous rock attributed to the
supposed hotspot and ensuing complications in the implied rate of hotspot motion.
Vogt and Jung attribute the origin of the Bermuda Rise to a reorganization of
plate tectonics
triggered by the closing of the Tethys Sea,
but allow that until more data is obtained this is very speculative. Detailed treatment of plate-tectonic-related theory for the explanation of intraplate volcanism has recently been summarised in a book called "Plates vs Plumes: A geological controversy" by Gillian R. Foulger.
Hotspot (geology)
The places known as hotspots or hot spots in geology are volcanic regions thought to be fed by underlying mantle that is anomalously hot compared with the mantle elsewhere. They may be on, near to, or far from tectonic plate boundaries. There are two hypotheses to explain them...
"
(or mantle plume) proposed to explain the Bermuda Rise (a cluster of extinct volcanoes
in the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
, including the island of Bermuda
Bermuda
Bermuda is a British overseas territory in the North Atlantic Ocean. Located off the east coast of the United States, its nearest landmass is Cape Hatteras, North Carolina, about to the west-northwest. It is about south of Halifax, Nova Scotia, Canada, and northeast of Miami, Florida...
), and also
invoked by Cox and Van Arsdale to explain the origin of the Mississippi Embayment
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 confluence with the Ohio River at Cairo, Illinois. The embayment...
and by Nunn to explain the Sabine Uplift (southwest of the Mississippi Embayment).
A hotspot origin for the Bermuda Rise has never been strongly supported, and has been largely shut out by a detailed and tightly argued paper by Vogt and Jung.
(See also shorter article at MantlePlumes.org
)
Evidence cited against a hotspot origin include:
1) Lack of a chain of age-progressive seamounts, such as with the
Hawaiian-Emperor
Hawaiian-Emperor seamount chain
The Hawaiian–Emperor seamount chain is composed of the Hawaiian ridge, consisting of the islands of the Hawaiian chain northwest to Kure Atoll, and the Emperor Seamounts, a vast underwater mountain region of islands and intervening seamounts, atolls, shallows, banks and reefs along a line trending...
or
Great Meteor
Great Meteor Seamount
The Great Meteor Seamount is a large guyot located south of the Azores in the Atlantic Ocean. It is the New England hotspot's most recent eruptive center and is one of the most completely investigated seamounts in the world. This guyot rises up from a depth of almost 4,800 meters to about 270...
seamount chains.
2) Elongation of the Bermuda Rise at a right angle to the direction of plate motion.
3) Various problems with the ages of igneous rock attributed to the
supposed hotspot and ensuing complications in the implied rate of hotspot motion.
Vogt and Jung attribute the origin of the Bermuda Rise to a reorganization of
plate tectonics
Tectonic Plates
Tectonic Plates is a 1992 independent Canadian film directed by Peter Mettler. Mettler also wrote the screenplay based on the play by Robert Lepage. The film stars Marie Gignac, Céline Bonnier and Robert Lepage.-Plot summary:...
triggered by the closing of the Tethys Sea,
but allow that until more data is obtained this is very speculative. Detailed treatment of plate-tectonic-related theory for the explanation of intraplate volcanism has recently been summarised in a book called "Plates vs Plumes: A geological controversy" by Gillian R. Foulger.