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African Plate 1

African Plate

The African plate, shown in pinkish-orange

The African Plate is a tectonic plate which

includes the continent of Africa, as well as

oceanic crust which lies between the

continent and various surrounding ocean

ridges.

Boundaries

The westerly side is a divergent boundary

with the North American Plate to the north

and the South American Plate to the south

forming the central and southern part of the

Mid-Atlantic Ridge. The African plate is

bounded on the northeast by the Arabian

Plate, the southeast by the Indo-Australian

Plate, the north by the Eurasian Plate and the Anatolian Plate, and on the south by the Antarctic Plate. All of these

are divergent or spreading boundaries with the exception of the northern boundary with the Eurasian Plate (except

for a short segment near the Azores, the Terceira Rift).

Components

The African Plate includes several cratons, stable blocks of old crust with deep roots in the subcontinental

lithospheric mantle, and less stable terranes, which came together to form the African continent during the assembly

of the supercontinent Pangea around 550 million years ago. The cratons are, from south to north, the Kalahari craton,Congo craton, Tanzania craton and West African craton. The cratons were widely separated in the past, but came

together during the Pan-African orogeny and stayed together when Gondwana split up. The cratons are connected by

orogenic belts, regions of highly deformed rock where the tectonic plates have engaged. The Saharan Metacraton has

been tentatively identified as the remains of a craton that has become detached from the subcontinental lithospheric

mantle, but alternatively may consist of a collection of unrelated crustal fragments swept together during the

Pan-African orogeny.

In some areas, the cratons are covered by sedimentary basins, such as the Tindouf basin, Taoudeni basin and Congo

basin, where the underlying archaic crust is overlaid by more recent Neoproterozoic sediments. The plate includes

shear zones such as the Central African Shear Zone (CASZ) where, in the past, two sections of the crust were

moving in opposite directions, and rifts such as the Anza trough where the crust was pulled apart, and the resulting

depression filled with more modern sediment.

http://en.wikipedia.org/w/index.php?title=Anza_troughhttp://en.wikipedia.org/w/index.php?title=Central_African_Shear_Zonehttp://en.wikipedia.org/w/index.php?title=Shear_zonehttp://en.wikipedia.org/w/index.php?title=Neoproterozoichttp://en.wikipedia.org/w/index.php?title=Archaichttp://en.wikipedia.org/w/index.php?title=Congo_basinhttp://en.wikipedia.org/w/index.php?title=Congo_basinhttp://en.wikipedia.org/w/index.php?title=Taoudeni_basinhttp://en.wikipedia.org/w/index.php?title=Tindouf_basinhttp://en.wikipedia.org/w/index.php?title=Sedimentary_basinhttp://en.wikipedia.org/w/index.php?title=Saharan_Metacratonhttp://en.wikipedia.org/w/index.php?title=Tectonic_plateshttp://en.wikipedia.org/w/index.php?title=Orogenyhttp://en.wikipedia.org/w/index.php?title=Pan-African_orogenyhttp://en.wikipedia.org/w/index.php?title=West_African_cratonhttp://en.wikipedia.org/w/index.php?title=Tanzania_cratonhttp://en.wikipedia.org/w/index.php?title=Congo_cratonhttp://en.wikipedia.org/w/index.php?title=Kalahari_cratonhttp://en.wikipedia.org/w/index.php?title=Pangeahttp://en.wikipedia.org/w/index.php?title=Supercontinenthttp://en.wikipedia.org/w/index.php?title=Terraneshttp://en.wikipedia.org/w/index.php?title=Mantle_%28geology%29http://en.wikipedia.org/w/index.php?title=Mantle_%28geology%29http://en.wikipedia.org/w/index.php?title=Cratonhttp://en.wikipedia.org/w/index.php?title=Terceira_Rifthttp://en.wikipedia.org/w/index.php?title=Azoreshttp://en.wikipedia.org/w/index.php?title=Antarctic_Platehttp://en.wikipedia.org/w/index.php?title=Anatolian_Platehttp://en.wikipedia.org/w/index.php?title=Eurasian_Platehttp://en.wikipedia.org/w/index.php?title=Indo-Australian_Platehttp://en.wikipedia.org/w/index.php?title=Indo-Australian_Platehttp://en.wikipedia.org/w/index.php?title=Arabian_Platehttp://en.wikipedia.org/w/index.php?title=Arabian_Platehttp://en.wikipedia.org/w/index.php?title=Mid-Atlantic_Ridgehttp://en.wikipedia.org/w/index.php?title=South_American_Platehttp://en.wikipedia.org/w/index.php?title=North_American_Platehttp://en.wikipedia.org/w/index.php?title=Divergent_boundaryhttp://en.wikipedia.org/w/index.php?title=Africahttp://en.wikipedia.org/w/index.php?title=Continenthttp://en.wikipedia.org/w/index.php?title=Tectonic_platehttp://en.wikipedia.org/w/index.php?title=File%3APlates_tect2_en.svg

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African Plate 2

Modern movements

Map of East Africa showing some of the historically active volcanoes(red

triangles) and the Afar Triangle (shaded, center) -- a triple junction where three

plates are pulling away from one another: the Arabian Plate, and the two parts of

the African Plate (the Nubian Plate and the Somali Plate) splitting along the East

African Rift Zone (USGS).

The African Plate is rifting in the eastern

interior along the East African Rift. This rift

zone separates the Nubian Plate to the west

from the Somali Plate to the east. One

hypothesis proposes the existence of amantle plume beneath the Afar region, while

an opposing hypothesis asserts that the

rifting is merely a zone of maximum

weakness where the African Plate is

deforming as plates to its east are moving

rapidly northward.

The African Plate's speed is estimated at

around 2.15 cm (0.85 in) per year. It has

been moving over the past 100 million yearsor so in a general northeast direction. This is

drawing it closer to the Eurasian Plate,

causing subduction where oceanic crust is

converging with continental crust (e.g.

portions of the central and eastern

Mediterranean). In the western

Mediterranean, the relative motions of the

Eurasian and African plates produce a combination of lateral and compressive forces, concentrated in a zone known

as the Azores-Gibraltar Fault Zone. Along its northeast margin, the African Plate is bounded by the Red Sea Rift

where the Arabian Plate is moving away from the African Plate.

The New England hotspot in the Atlantic Ocean has probably created a short line of mid to late-Tertiary age

seamounts on the African Plate but appears to be currently inactive.[1]

References

[1] Age Progressive Volcanism in the New England Seamounts and the opening of the Central Atlantic Ocean (http://adsabs.harvard. edu/abs/

1984JGR. . . .89.9980D) Retrieved on 2007-10-05

External links

USGS - Understanding plate motions (http://pubs.usgs.gov/publications/text/understanding.html) Cenozoic dynamics of the African plate with emphasis on the Africa-Eurasia collision (http://adsabs.harvard.

edu/cgi-bin/nph-bib_query?bibcode=1999JGR... 104.7405M& amp;db_key=PHY&data_type=HTML&

amp;format=)

Huang, Zhen Shao (1997). "Speed of the Continental Plates" (http://hypertextbook.com/facts/ZhenHuang.

shtml). The Physics Factbook.

http://hypertextbook.com/facts/ZhenHuang.shtmlhttp://hypertextbook.com/facts/ZhenHuang.shtmlhttp://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1999JGR...104.7405M&db_key=PHY&data_type=HTML&format=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1999JGR...104.7405M&db_key=PHY&data_type=HTML&format=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1999JGR...104.7405M&db_key=PHY&data_type=HTML&format=http://pubs.usgs.gov/publications/text/understanding.htmlhttp://adsabs.harvard.edu/abs/1984JGR....89.9980Dhttp://adsabs.harvard.edu/abs/1984JGR....89.9980Dhttp://en.wikipedia.org/w/index.php?title=Seamounthttp://en.wikipedia.org/w/index.php?title=Tertiaryhttp://en.wikipedia.org/w/index.php?title=Atlantic_Oceanhttp://en.wikipedia.org/w/index.php?title=New_England_hotspothttp://en.wikipedia.org/w/index.php?title=Arabian_Platehttp://en.wikipedia.org/w/index.php?title=Red_Sea_Rifthttp://en.wikipedia.org/w/index.php?title=Azores-Gibraltar_Transform_Faulthttp://en.wikipedia.org/w/index.php?title=Mantle_plumehttp://en.wikipedia.org/w/index.php?title=Somali_Platehttp://en.wikipedia.org/w/index.php?title=East_African_Rifthttp://en.wikipedia.org/w/index.php?title=Rift_%28geology%29http://en.wikipedia.org/w/index.php?title=File%3AEAfrica.gifhttp://en.wikipedia.org/w/index.php?title=Somali_Platehttp://en.wikipedia.org/w/index.php?title=Triple_junction

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Article Sources and Contributors 3

Article Sources and ContributorsAfrican Plate Source: http://en.wikipedia.org/w/index.php?oldid=550069074 Contributors: Aa2-2004, Ahoerstemeier, AlexiusHoratius, Alro, Aymatth2, Bdewaele, Ben Ben, Blanchardb,CommonsDelinker, Download, Elert, Eric-Wester, Faigl.ladislav, Florian Huber, Geologyguy, Glacialfox, Gwernol, Hadal, Hede2000, Hellbus, Hmains, Howard the Duck, Hunnjazal, Interiot,Invitamia, Ivan tambuk, Jackfork, Khalid Mahmood, Kipala, Littleteddy, Magioladitis, Magus732, Maine12329, Merovingian, Middayexpress, Mikenorton, Morel, NatureA16, Nightstallion,Ouro, Quadell, Ratemonth, Raven in Orbit, RekishiEJ, RexNL, Rich Farmbrough, Rmashhadi, Runefrost, Rmih, Seth Ilys, Solarra, StuRat, Swid, Synergy, Tmangray, Volcanoguy, Vsmith, Wkmuriithi, Zvn, 73 anonymous edits

Image Sources, Licenses and ContributorsImage:Plates tect2 en.svg Source: http://en.wikipedia.org/w/index.php?title=File:Plates_tect2_en.svg License: Public Domain Contributors: USGS

Image:EAfrica.gif Source: http://en.wikipedia.org/w/index.php?title=File:EAfrica.gifLicense: Public Domain Contributors: USGS

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