Kerguelen Plateau
A large igneous plateau in the Indian Ocean.
via Wikipedia: Oceanic plateau · see source
The Kerguelen Plateau is an oceanic plateau located in the Indian Ocean. It is one of 184 oceanic plateaus in the world. The source notes that parts of Kerguelen are made of rifted continental crust. The plateau is one of the three largest plateaus, along with the Caribbean and Ontong Java, and is located on a thermal swell. It is also one of the three large Cretaceous oceanic plateaus in the Pacific and Indian Ocean, alongside Ontong Java and the Caribbean.
- type
- Oceanic plateau and large igneous province (LIP)
Lore & Background
The Kerguelen Plateau is an oceanic plateau produced by a large igneous province, often associated with hotspots, mantle plumes, and volcanic islands. The source specifically lists Kerguelen as an example of such a plateau, alongside Iceland, Hawaii, and Cape Verde. It is one of the three largest plateaus, located on a thermal swell. The source also states that parts of Kerguelen are made of rifted continental crust, similar to the Falkland Plateau, Lord Howe Rise, and parts of the Seychelles and Arctic ridges. The Kerguelen Plateau is one of the three most recent plateaus formed, the large Cretaceous oceanic plateaus in the Pacific and Indian Ocean: Ontong Java, Kerguelen, and Caribbean.
Reader's Guide
The Kerguelen Plateau is a significant feature for understanding crust–mantle recycling. Geologists believe that igneous oceanic plateaus like Kerguelen may represent a stage in the development of continental crust, as they are generally less dense than oceanic crust while still being denser than normal continental crust. Igneous oceanic plateaus have a ratio of silicon intermediate between continental and oceanic crust, though they are more mafic than felsic. When a plate carrying oceanic crust subducts under a plate carrying an igneous oceanic plateau, the volcanism which erupts on the plateau as the oceanic crust heats up on its descent into the mantle erupts material which is more felsic than the material which makes up the plateau. This represents a step toward creating crust which is increasingly continental in character, being less dense and more buoyant. If an igneous oceanic plateau is subducted underneath another one, or under existing continental crust, the eruptions produced thereby produce material that is yet more felsic, and so on through geologic time.
Did You Know?
- The Kerguelen Plateau is one of the three largest oceanic plateaus, along with the Caribbean and Mid-Pacific Mountains.
- Parts of the Kerguelen Plateau are made of rifted continental crust.
- The Kerguelen Plateau is one of the three large Cretaceous oceanic plateaus in the Pacific and Indian Ocean.
- The Kerguelen Plateau is an example of an oceanic plateau associated with a hotspot, mantle plume, and volcanic islands.
- Igneous oceanic plateaus like Kerguelen are more buoyant than oceanic crust and tend to withstand subduction.
Frequently Asked Questions
What is the Kerguelen Plateau?
It is a vast oceanic plateau and large igneous province resting on the Antarctic Plate in the southern Indian Ocean. It is also called the Kerguelen–Heard Plateau and was built up by the Kerguelen hotspot.
Where is the Kerguelen Plateau located?
It sits roughly 3,000 km southwest of Australia on the Antarctic Plate in the southern Indian Ocean. The feature stretches more than 2,200 km along a northwest-to-southeast axis.
How big is the Kerguelen Plateau?
The plateau spans approximately 1,226,230 square kilometres, an area comparable to the size of South Africa. The majority of it lies less than 3,000 metres below sea level.
How was the Kerguelen Plateau formed?
Its formation began around 130 million years ago, coinciding with or following the rifting apart of the supercontinent Gondwana. The Kerguelen hotspot drove the enormous volume of volcanic material that created the plateau.
Which parts of the Kerguelen Plateau are above sea level?
Only a small sliver breaches the surface, giving rise to the Kerguelen Islands (a French overseas territory) and the Heard and McDonald Islands (an Australian external territory).
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