North Atlantic Igneous Province
Encyclopedia
The North Atlantic Igneous Province (NAIP) is a large igneous province
estimated to be at least 1.3 km2 in area and 6.6 km3 in volume. Geographically, the NAIP makes up all of the North Atlantic Ocean
as well as the Paleocene
and Eocene
basalt
s of Greenland
, Iceland
, the United Kingdom
, Denmark
, Norway
and many of the islands located in the north eastern portion of the North Atlantic ocean.
Isotopic dating
indicates the most active magmatic phase of the NAIP was between ca.
60.5 and ca. 54.5 Ma (million years ago) (mid-Paleocene to early Eocene) - further divided into Phase 1 (pre-break-up phase) dated to ca. 62-58 Ma and Phase 2 (syn-break-up phase) dated to ca. 56-54 Ma.
Continuing research also indicates that continental plate movement
(Eurasian
, Greenland
, and North American
), that regional rifting events, and that seafloor spreading
between Labrador
and Greenland may have begun as early as ca. 95-80 Ma, ca. 81 Ma, and ca. 63-61 Ma respectively (late Cretaceous
to early Paleocene).
The formation of the NAIP has also been linked to the Iceland hotspot
/ mantle plume
. Through both geochemical
observations and reconstructions of paleogeography, it is speculated that the present day Iceland hotspot originated as a mantle plume on the Alpha Ridge
(Arctic Ocean
) ca. 130-120 Ma, migrated down Ellesmere Island
, through Baffin Island
, onto the west coast of Greenland, and finally arrived on the east coast of Greenland by ca. 60 Ma.
The present-day Iceland and Jan Mayen hotspot
s and North Atlantic Ridge
are still geologically active.
The NAIP is made up of both onshore and offshore basalt floods
, sills
, dykes
, and plateaus. Dependent upon various regional locations, the NAIP is made up of MORB (Mid Ocean Ridge Basalt), alkali basalt, tholeiitic basalt, and picrite basalt
.
Synonymous or related names
Large igneous province
A Large Igneous Province is an extremely large accumulation of igneous rocks—intrusive, extrusive, or both—in the earth's crust...
estimated to be at least 1.3 km2 in area and 6.6 km3 in volume. Geographically, the NAIP makes up all of the North 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...
as well as the Paleocene
Paleocene
The Paleocene or Palaeocene, the "early recent", is a geologic epoch that lasted from about . It is the first epoch of the Palaeogene Period in the modern Cenozoic Era...
and Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...
s of Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
, Iceland
Iceland
Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...
, the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, Denmark
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
, Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
and many of the islands located in the north eastern portion of the North Atlantic ocean.
Isotopic dating
Radiometric dating
Radiometric dating is a technique used to date materials such as rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates...
indicates the most active magmatic phase of the NAIP was between ca.
Circa
Circa , usually abbreviated c. or ca. , means "approximately" in the English language, usually referring to a date...
60.5 and ca. 54.5 Ma (million years ago) (mid-Paleocene to early Eocene) - further divided into Phase 1 (pre-break-up phase) dated to ca. 62-58 Ma and Phase 2 (syn-break-up phase) dated to ca. 56-54 Ma.
Continuing research also indicates that continental plate movement
Plate tectonics
Plate tectonics is a scientific theory that describes the large scale motions of Earth's lithosphere...
(Eurasian
Eurasian Plate
The Eurasian Plate is a tectonic plate which includes most of the continent of Eurasia , with the notable exceptions of the Indian subcontinent, the Arabian subcontinent, and the area east of the Chersky Range in East Siberia...
, Greenland
North American Plate
The North American Plate is a tectonic plate covering most of North America, Greenland, Cuba, Bahamas, and parts of Siberia, Japan and Iceland. It extends eastward to the Mid-Atlantic Ridge and westward to the Chersky Range in eastern Siberia. The plate includes both continental and oceanic crust...
, and North American
North American Plate
The North American Plate is a tectonic plate covering most of North America, Greenland, Cuba, Bahamas, and parts of Siberia, Japan and Iceland. It extends eastward to the Mid-Atlantic Ridge and westward to the Chersky Range in eastern Siberia. The plate includes both continental and oceanic crust...
), that regional rifting events, and that seafloor spreading
Seafloor spreading
Seafloor spreading is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. Seafloor spreading helps explain continental drift in the theory of plate tectonics....
between Labrador
Labrador
Labrador is the distinct, northerly region of the Canadian province of Newfoundland and Labrador. It comprises the mainland portion of the province, separated from the island of Newfoundland by the Strait of Belle Isle...
and Greenland may have begun as early as ca. 95-80 Ma, ca. 81 Ma, and ca. 63-61 Ma respectively (late Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
to early Paleocene).
The formation of the NAIP has also been linked to the Iceland hotspot
Iceland hotspot
The Iceland hotspot is a hotspot which is partly responsible for the high volcanic activity which has formed the island of Iceland.-Description:...
/ mantle plume
Mantle plume
A mantle plume is a hypothetical thermal diapir of abnormally hot rock that nucleates at the core-mantle boundary and rises through the Earth's mantle. Such plumes were invoked in 1971 to explain volcanic regions that were not thought to be explicable by the then-new theory of plate tectonics. Some...
. Through both geochemical
Isotope geochemistry
Isotope geochemistry is an aspect of geology based upon study of the relative and absolute concentrations of the elements and their isotopes in the Earth. Variations in the abundance of these isotopes, typically measured with an isotope ratio mass spectrometer or an accelerator mass spectrometer,...
observations and reconstructions of paleogeography, it is speculated that the present day Iceland hotspot originated as a mantle plume on the Alpha Ridge
Alpha Ridge
The Alpha Ridge is a major volcanic ridge under the Arctic Ocean between the Canada Basin and the Lomonosov Ridge. It was active during the formation of the Amerasian Basin. It was discovered in 1963. The highest elevation is about 2.7 km over the ocean floor. It is 200 to 450 km wide...
(Arctic Ocean
Arctic Ocean
The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...
) ca. 130-120 Ma, migrated down Ellesmere Island
Ellesmere Island
Ellesmere Island is part of the Qikiqtaaluk Region of the Canadian territory of Nunavut. Lying within the Canadian Arctic Archipelago, it is considered part of the Queen Elizabeth Islands, with Cape Columbia being the most northerly point of land in Canada...
, through Baffin Island
Baffin Island
Baffin Island in the Canadian territory of Nunavut is the largest island in the Canadian Arctic Archipelago, the largest island in Canada and the fifth largest island in the world. Its area is and its population is about 11,000...
, onto the west coast of Greenland, and finally arrived on the east coast of Greenland by ca. 60 Ma.
The present-day Iceland and Jan Mayen hotspot
Jan Mayen hotspot
The Jan Mayen hotspot is a volcanic hotspot responsible for the volcanic activity that has formed the island of Jan Mayen in the northern Atlantic Ocean.-See also:*Beerenberg volcano...
s and North Atlantic Ridge
Mid-Atlantic Ridge
The Mid-Atlantic Ridge is a mid-ocean ridge, a divergent tectonic plate boundary located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world. It separates the Eurasian Plate and North American Plate in the North Atlantic, and the African Plate from the South...
are still geologically active.
The NAIP is made up of both onshore and offshore basalt floods
Flood basalt
A flood basalt or trap basalt is the result of a giant volcanic eruption or series of eruptions that coats large stretches of land or the ocean floor with basalt lava. Flood basalts have occurred on continental scales in prehistory, creating great plateaus and mountain ranges...
, sills
Sill (geology)
In geology, a sill is a tabular sheet intrusion that has intruded between older layers of sedimentary rock, beds of volcanic lava or tuff, or even along the direction of foliation in metamorphic rock. The term sill is synonymous with concordant intrusive sheet...
, dykes
Dike swarm
A dike swarm or dyke swarm is a large geological structure consisting of a major group of parallel, linear, or radially oriented dikes intruded within continental crust. They consist of several to hundreds of dikes emplaced more or less contemporaneously during a single intrusive event and are...
, and plateaus. Dependent upon various regional locations, the NAIP is made up of MORB (Mid Ocean Ridge Basalt), alkali basalt, tholeiitic basalt, and picrite basalt
Picrite basalt
Picrite basalt, picrobasalt or oceanite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine. It is dark with yellow-green olivine phenocrysts and black to dark brown pyroxene, mostly augite....
.
Synonymous or related names
- Brito-Arctic provinceBrito-Arctic provinceThe Brito-Arctic province is a major flood basalt province of the North Atlantic Ocean. Basaltic volcanism flowed in two main pulses. The first which occurred ~61 million years ago was of 2 x 106 km³ in total volume, into the current western and southeastern Greenland and northwestern Britain...
(BAP) - North Atlantic Tertiary Province (NATP)
- North Atlantic Volcanic Province (NAVP)
- North Atlantic Basalt Province (NABP)
- North Atlantic Tertiary Volcanic Province (NATVP)
- British Tertiary Igneous Province (BTIP)
- British Tertiary Volcanic Province (BTVP)
- British Paleogene Igneous Province (BPIP)
- Thulean PlateauThulean PlateauThe Thulean Plateau also known as the Thulean Province, was a great basaltic lava plain that existed during the Paleogene Period, which possibly extended over 1,800,000 km2 in the northern Atlantic Ocean region...
See also
- Igneous rockIgneous rockIgneous rock is one of the three main rock types, the others being sedimentary and metamorphic rock. Igneous rock is formed through the cooling and solidification of magma or lava...
- Geologic provinceGeologic provinceA geologic or geomorphic province is a spatial entity with common geologic or geomorphic attributes. A province may include a single dominant structural element such as a basin or a fold belt, or a number of contiguous related elements...
- Mantle plumeMantle plumeA mantle plume is a hypothetical thermal diapir of abnormally hot rock that nucleates at the core-mantle boundary and rises through the Earth's mantle. Such plumes were invoked in 1971 to explain volcanic regions that were not thought to be explicable by the then-new theory of plate tectonics. Some...
- HotspotHotspot (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...
- Oceanic plateauOceanic plateauAn oceanic plateau is a large, relatively flat submarine region that rises well above the level of the ambient seabed. While many oceanic plateaus are composed of continental crust, and often form a step interrupting the continental slope, some plateaus are undersea remnants of large igneous...
- Continental flood basaltFlood basaltA flood basalt or trap basalt is the result of a giant volcanic eruption or series of eruptions that coats large stretches of land or the ocean floor with basalt lava. Flood basalts have occurred on continental scales in prehistory, creating great plateaus and mountain ranges...
- Large igneous provinceLarge igneous provinceA Large Igneous Province is an extremely large accumulation of igneous rocks—intrusive, extrusive, or both—in the earth's crust...
- Dike swarmDike swarmA dike swarm or dyke swarm is a large geological structure consisting of a major group of parallel, linear, or radially oriented dikes intruded within continental crust. They consist of several to hundreds of dikes emplaced more or less contemporaneously during a single intrusive event and are...
External links
- Map of NAIP http://petrology.oxfordjournals.org/cgi/content/full/41/7/1023/FIG1 - from Mantle Sources and Melting Dynamics in the British Paleogene British Province; Kent and Fitton, Journal of Petrology, 2000; articlehttp://petrology.oxfordjournals.org/cgi/content/full/41/7/1023#FIG1
- Paleogeographic Map of NAIPhttp://petrology.oxfordjournals.org/cgi/content/full/41/7/919/FIG1 - from The Sub Lithospheric Source Of North Atlantic Basalts; Ellam and Stuart; Journal of Petrology, 2000; articlehttp://petrology.oxfordjournals.org/cgi/content/full/41/7/919#FIG1
- Mantle Plumes - Iceland Hotspot pagehttp://www.mantleplumes.org/TopPages/IcelandTop.html
- Large Igneous Province Commission - home pagehttp://www.largeigneousprovinces.org/index.html