Craton
[[Image:World geologic provinces.jpg|thumb|right|300px|World geologic provinces. ({{USGS}})
Oceanic crustGeologic province]]A
craton (kratos; Greek for strength) is an old and stable part of the
continental crust that has survived the merging and splitting of
continents and
supercontinents for at least 500 million years. Cratons are generally found in the interiors of continents and are formed of a crust of lightweight
felsic igneous rock such as
granite attached to a section of the upper
mantle. A craton may extend to depth of 200 km.
Cratons are subdivided geographically into
geologic provinces, each province being classified as an Archon, a Proton or a Tecton according to its age:
*Archons: consist of rocks from the
Archaean era, older than 2.5 billion years (2.5 Ga).
*Protons: consist of rocks from the early to middle
Proterozoic era, older than 1.6 Ga.
*Tectons: consist of rocks from the late
Proterozoic era, with ages between 1.6 Ga and 800 million years (800 Ma).
As minerals (such as precious metals and
diamonds) in the Earth's crust tend to become separated with time, the oldest cratons are of the greatest interest to mining companies. Cratons are still being defined by ongoing
geological and
geophysical research.
Listed by modern continent, include:
Australia
**Altjawarra craton
**Central craton
**Curnamona craton, South Australia
**
Gawler craton, central South Australia
**
Pilbara craton, Western Australia
**
Yilgarn craton, Western Australia (4.4 Ga)
Americas
[[Image:North america craton nps.gif|thumb|{{North American craton}}
]]
**
Amazonian craton
**
Canadian Shield (or Laurentian Shield or Precambrian Shield)
**
Churchill craton**
Guiana Shield**
North American craton**
Rae craton**
Slave craton, Northwest Canada
**
Superior craton, Canada and northern United States
**
Wyoming craton
Africa
**Arabian craton
**
Congo craton, central southern Africa
***
Bangweulu Block,
Zambia**Kaapvaal craton,
South Africa (3.6 - 2.5 Ga)
**
Kalahari craton
**Saharan craton,
Algeria**
Tanzanian craton
**West African craton
**
Zaire craton
**
Zimbabwean craton (3.5 Ga)
Eurasia
**
Dharwar craton,
India (3.4 - 2.6 Ga)
**East China craton
**Indian craton
**
North China craton (2.5 Ga)
**
Sarmatian craton (3.7 - 2.8 Ga)
**
Siberian craton**Sino-
Korean craton, Northern
China**Tarim craton, China
**
Volgo-
Uralian craton,
Russia (3.0 - 2.7 Ga)
**
Yangtze craton
Northern and Eastern Europe
**
East European craton**Belomorian craton, part of the Fennoscandian Shield, between the Karelian and Kola cratons
**
Baltic Shield, part of the East European craton
**
Fennoscandian Shield, the exposed Northwestern part of the Baltic Shield in Norway, Sweden and Finland (3.1 Ga)
**Karelian craton, part of the Fennoscandian Shield in Southeast
Finland and
Karelia Russia, (3.4 Ga)
**Kola craton, part of the Fennoscandian Shield,
Kola Peninsula, Northwest
Russia**Midland craton of
England and
Wales**North Atlantic Craton
Antarctica
**
East Antarctic craton
