![Portion of the New England hotspot](https://upload.wikimedia.org/wikipedia/commons/9/96/Portion_of_the_New_England_hotspot.png)
The New England hotspot, also referred to as the Great Meteor hotspot and sometimes the Monteregian hotspot, is a
volcanic
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plates a ...
hotspot in the
North 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 an ...
. It created the
Monteregian Hills
The Monteregian Hills (french: Collines Montérégiennes) is a linear chain of isolated hills in Montreal and Montérégie, between the Laurentians and the Appalachians.
Etymology
The first definition of the Monteregian Hills came about in 190 ...
intrusion
In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...
s in
Montreal
Montreal ( ; officially Montréal, ) is the List of the largest municipalities in Canada by population, second-most populous city in Canada and List of towns in Quebec, most populous city in the Provinces and territories of Canada, Canadian ...
and
Montérégie
Montérégie () is an administrative region in the southwest part of Quebec. It includes the cities of Boucherville, Brossard, Châteauguay, Longueuil, Saint-Hyacinthe, Saint-Jean-sur-Richelieu, Salaberry-de-Valleyfield and Vaudreuil-Dorion.
The ...
, the
White Mountains intrusions in
New Hampshire
New Hampshire is a U.S. state, state in the New England region of the northeastern United States. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Gulf of Maine to the east, and the Canadian province of Quebec t ...
, the
New England
New England is a region comprising six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York to the west and by the Canadian provinces ...
and
Corner Rise seamount
A seamount is a large geologic landform that rises from the ocean floor that does not reach to the water's surface (sea level), and thus is not an island, islet or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abru ...
s off the coast of North America, and the
Seewarte Seamounts east of the
Mid-Atlantic Ridge
The Mid-Atlantic Ridge is a mid-ocean ridge (a divergent or constructive plate boundary) located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world. In the North Atlantic, the ridge separates the North Ame ...
on the
African Plate
The African Plate is a major tectonic plate that includes much of the continent of Africa (except for its easternmost part) and the adjacent oceanic crust to the west and south. It is bounded by the North American Plate and South American Plat ...
, the latter of which include its most recent eruptive center, the
Great Meteor Seamount
The Great Meteor Seamount, also called the Great Meteor Tablemount, is a guyot and the largest seamount in the North Atlantic with a volume of . It is one of the Seewarte Seamounts, rooted on a large terrace located south of the Azores Plateau. ...
.
The New England,
Great Meteor, or Monteregian
hotspot track has been used to estimate the movement of the
North American Plate
The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Pacific ...
away from the
African Plate
The African Plate is a major tectonic plate that includes much of the continent of Africa (except for its easternmost part) and the adjacent oceanic crust to the west and south. It is bounded by the North American Plate and South American Plat ...
from the early
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
period to the present using the fixed hotspot reference frame.
Geologic history
The geologic history of the New England hotspot is the subject of much debate among geoscientists. The conventional opinion is that volcanic activity associated with the hotspot results from movement of the
North American Plate
The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Pacific ...
over a fixed
mantle plume
A mantle plume is a proposed mechanism of convection within the Earth's mantle, hypothesized to explain anomalous volcanism. Because the plume head partially melts on reaching shallow depths, a plume is often invoked as the cause of volcanic hot ...
. During the first major episodes of volcanic activity, the plume created the
igneous intrusions
Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or ...
of the
Monteregian Hills
The Monteregian Hills (french: Collines Montérégiennes) is a linear chain of isolated hills in Montreal and Montérégie, between the Laurentians and the Appalachians.
Etymology
The first definition of the Monteregian Hills came about in 190 ...
in southern
Quebec
Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is one of the thirtee ...
and the younger set of intrusions of the
White Mountains in
New Hampshire
New Hampshire is a U.S. state, state in the New England region of the northeastern United States. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Gulf of Maine to the east, and the Canadian province of Quebec t ...
around 124-100 Ma. As the plate moved further west, the plume moved offshore, forming the
New England Seamounts
The New England Seamounts is a chain of over twenty underwater extinct volcanic mountains known as seamounts. This chain is located off the coast of Massachusetts in the Atlantic Ocean and extends over 1,000 km from the edge of Georges Ban ...
between 103 and 83 Ma. After the formation of the Nashville Seamount around 83 Ma, there was a pause in volcanic activity and the volcanic center shifted north, creating the Corner Rise Seamounts around 80-76 Ma. The Mid-Atlantic Ridge passed over the plume around 76 Ma and renewed volcanic activity produced the Seewarte Seamounts on the African Plate between 26 and 10 Ma.
[
Evidence for a plume origin includes the above age progression, seismic anomalies in the lower ]mantle
A mantle is a piece of clothing, a type of cloak. Several other meanings are derived from that.
Mantle may refer to:
*Mantle (clothing), a cloak-like garment worn mainly by women as fashionable outerwear
**Mantle (vesture), an Eastern Orthodox ve ...
under the Great Meteor Seamount (though these do not extend into the upper mantle as expected for a plume), and helium isotope ratios in groundwater in the Monteregian Hills which indicate a deep mantle source. The lack of an obvious hotspot track west of Montreal has previously been ascribed to failure of the plume to penetrate the Canadian Shield
The Canadian Shield (french: Bouclier canadien ), also called the Laurentian Plateau, is a geologic shield, a large area of exposed Precambrian igneous and high-grade metamorphic rocks. It forms the North American Craton (or Laurentia), the anc ...
, a lack of recognizable intrusions due to erosion, or strengthening of the plume when it approached the Monteregian Hills,[ but more recent research has found ]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 ...
fields in Ontario
Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Ca ...
and New York
New York most commonly refers to:
* New York City, the most populous city in the United States, located in the state of New York
* New York (state), a state in the northeastern United States
New York may also refer to:
Film and television
* '' ...
dated between 180 and 134 Ma and at Rankin Inlet
Rankin Inlet ( iu, Kangiqliniq; Inuktitut syllabics: ᑲᖏᕿᓂᖅ or ''Kangirliniq'', ᑲᖏᖅᖠᓂᖅ, or ''Kangir&iniq'' meaning ''deep bay/inlet'') is an Inuit hamlet on Kudlulik Peninsula in Nunavut, Canada. It is the largest hamlet a ...
to the northwest of Hudson Bay
Hudson Bay ( crj, text=ᐐᓂᐯᒄ, translit=Wînipekw; crl, text=ᐐᓂᐹᒄ, translit=Wînipâkw; iu, text=ᑲᖏᖅᓱᐊᓗᒃ ᐃᓗᐊ, translit=Kangiqsualuk ilua or iu, text=ᑕᓯᐅᔭᕐᔪᐊᖅ, translit=Tasiujarjuaq; french: b ...
dated between 214-192 Ma which may represent an older, continental extension of the hotspot track.
Some evidence, such the lack of an initial flood basalt
Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...
and age progression along the New England-Quebec volcanic province, is not what is expected for a plume origin, and the case has been made that a shallow, tectonic mechanism is more plausible. In this view, the two spikes in activity that formed the New England-Quebec volcanic province and New England Seamounts are due to passive, shallow melting associated with lithospheric
A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust and the portion of the upper mantle that behaves elastically on time scales of up to thousands of years o ...
extension resulting from tectonic changes in the Atlantic Ocean which reactivated pre-existing zones of structural weakness related to the earlier opening of the Iapetus Ocean
The Iapetus Ocean (; ) was an ocean that existed in the late Neoproterozoic and early Paleozoic eras of the geologic timescale (between 600 and 400 million years ago). The Iapetus Ocean was situated in the southern hemisphere, between the paleoco ...
.[ The more recent seamounts are thought to mark discrete episodes of volcanic activity along different lines or segments of the same structural trend rather than movement of the plate over a fixed mantle plume.][ The timing of volcanic activity which coincides with major reorganisations of plate boundaries,][ as well as geochemical analysis of the Monteregian ]pluton
In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...
s which indicates a lithospheric mantle source, support this interpretation.
See also
*Great Meteor hotspot track
The New England hotspot, also referred to as the Great Meteor hotspot and sometimes the Monteregian hotspot, is a volcanic hotspot in the North Atlantic Ocean. It created the Monteregian Hills intrusions in Montreal and Montérégie, the White ...
*Volcanism of Northern Canada
Volcanism of Northern Canada has produced hundreds of volcanic areas and extensive lava formations across Northern Canada. The region's different volcano and lava types originate from different tectonic settings and types of volcanic eruptions, ra ...
*Volcanism of Eastern Canada
The volcanology of Eastern Canada includes the hundreds of volcanic areas and extensive lava formations in Eastern Canada. The region's different volcano and lava types originate from different tectonic settings and types of volcanic eruptions, ra ...
*Volcanism of Canada
Volcanic activity is a major part of the geology of Canada and is characterized by many types of volcanic landform, including lava flows, volcanic plateaus, lava domes, cinder cones, stratovolcanoes, shield volcanoes, submarine volcanoes, calder ...
References
{{Hotspots
Hotspots of the Atlantic Ocean
Volcanism of Nunavut
Volcanism of Ontario
Volcanism of Quebec
Natural history of Nunavut
Natural history of Ontario
Natural history of Quebec
Natural history of New Hampshire