| 31. | It needs no assistance on the craton.
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| 32. | Most crustal rocks formed before 2.5 billion years ago are located in cratons.
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| 33. | Like all cratons, the latter is composed of the crystalline basement and sedimentary cover.
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| 34. | Cratons are subdivided geographically into geologic provinces.
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| 35. | Metaigneous and metavolcanic rocks form the largest component of cratons and are high in silica.
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| 36. | Thick successions of carbonate rocks are often deposited on craton margins during sea level rise.
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| 37. | The greenstone belts of the various archean cratons are commonly altered to the greenschist facies.
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| 38. | Layered intrusions are found in typically ancient cratons and are rare but worldwide in distribution.
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| 39. | The Pilbara craton in western Australia is not well defined but formed around 3 Gya.
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| 40. | The Siberian craton, Australia and eastern Antarctica have all been suggested based paleomagnetic information.
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