Map showing Earth's lithosphere divided into 15 principal tectonic plates
Map showing Earth's lithosphere divided into 15 principal tectonic plates
Plate tectonics map from NASA
Plate tectonics map from NASA

This is a list of tectonic plates on Earth's surface. Tectonic plates are pieces of Earth's crust and uppermost mantle, together referred to as the lithosphere. The plates are around 100 km (62 mi) thick and consist of two principal types of material: oceanic crust (also called sima from silicon and magnesium) and continental crust (sial from silicon and aluminium). The composition of the two types of crust differs markedly, with mafic basaltic rocks dominating oceanic crust, while continental crust consists principally of lower-density felsic granitic rocks.

Current plates

Map showing Earth's principal tectonic plates and their boundaries in detail
Map showing Earth's principal tectonic plates and their boundaries in detail

Geologists generally agree that the following tectonic plates currently exist on Earth's surface with roughly definable boundaries. Tectonic plates are sometimes subdivided into three fairly arbitrary categories: major (or primary) plates, minor (or secondary) plates, and microplates (or tertiary plates).[1]

Major plates

These plates comprise the bulk of the continents and the Pacific Ocean. For purposes of this list, a major plate is any plate with an area greater than 20 million km2.

Minor plates

These smaller plates are often not shown on major plate maps, as the majority do not comprise significant land area. For purposes of this list, a minor plate is any plate with an area less than 20 million km2 but greater than 1 million km2.

Microplates

These plates are often grouped with an adjacent principal plate on a tectonic plate world map. For purposes of this list, a microplate is any plate with an area less than 1 million km2. Some models identify more minor plates within current orogens (events that lead to a large structural deformation of Earth's lithosphere) like the Apulian, Explorer, Gorda, and Philippine Mobile Belt plates. New research can change the scientific consensus as to whether such plates should be considered distinct portions of the crust.[2][3][4][5]

Ancient continental formations

In the history of Earth many tectonic plates have come into existence and have over the intervening years either accreted onto other plates to form larger plates, rifted into smaller plates, or have been crushed by or subducted under other plates.

Ancient supercontinents

Supercontinent – Landmass comprising more than one continental core, or craton

The following list includes the supercontinents known or speculated to have existed in the Earth's past:

Ancient plates and cratons

Not all plate boundaries are easily defined, especially for ancient pieces of crust. The following list of ancient cratons, microplates, plates, shields, terranes, and zones no longer exist as separate plates. Cratons are the oldest and most stable parts of the continental lithosphere and shields are the exposed area of a craton(s). Microplates are tiny tectonic plates, terranes are fragments of crustal material formed on one tectonic plate and accreted to crust lying on another plate, and zones are bands of similar rocks on a plate formed by terrane accretion or native rock formation. Terranes may or may not have originated as independent microplates: a terrane may not contain the full thickness of the lithosphere.

African Plate

Antarctic Plate

Eurasian Plate

Indo-Australian Plate

Basic geological regions of Australia, by age
Basic geological regions of Australia, by age
Map of chronostratigraphic divisions of India
Map of chronostratigraphic divisions of India

North American Plate

North American cratons and basement rocks
North American cratons and basement rocks

South American Plate

See also

Notes and references

Notes

  1. ^ 15,600,000 km2 is the original size before the 2017 split of the Coiba and Malpelo plates.

References

  1. ^ Madaan, About Sonia (2020-08-18). "7 Major Tectonic Plates (Pacific, African, Eurasian, Antarctic and more)". Earth Eclipse. How Many Tectonic Plates Are on Earth?. Retrieved 2022-05-12.
  2. ^ Tetsuzo Seno, Taro Sakurai, and Seth Stein. 1996. Can the Okhotsk plate be discriminated from the North American plate? J. Geophys. Res., 101, 11305-11315 (abstract)
  3. ^ Bird, P. (2003). "An updated digital model of plate boundaries". Geochemistry, Geophysics, Geosystems 4 (3): 1027. doi:10.1029/2001GC000252. http://peterbird.name/publications/2003_PB2002/2003_PB2002.htm.
  4. ^ Timothy M. Kusky; Erkan Toraman & Tsilavo Raharimahefa (2006-11-20). "The Great Rift Valley of Madagascar: An extension of the Africa–Somali diffusive plate boundary?". International Association for Gondwana Research Published by Elsevier B.V.
  5. ^ Niels Henriksen; A.K. Higgins; Feiko Kalsbeek; T. Christopher R. Pulvertaft (2000). "Greenland from Archaean to Quaternary" (PDF). No. 185. Greenland Survey Bulletin. Archived from the original (PDF) on 2008-12-07. Retrieved 2009-10-04.
  6. ^ Antarctic Plate Tectonics

Bibliography

North Andes Plate