<Tr> <Td> Shield Platform Orogen Basin Large igneous province Extended crust <P> </P> </Td> <Td> Oceanic crust: 0--20 Ma 20--65 Ma> 65 Ma <P> </P> </Td> </Tr> <P> A craton (/ ˈkreɪtɒn /, / ˈkrætɒn /, or / ˈkreɪtən /; from Greek: κράτος kratos "strength") is an old and stable part of the continental lithosphere, where the lithosphere consists of the Earth's two topmost layers, the crust and the uppermost mantle . Having often survived cycles of merging and rifting of continents, cratons are generally found in the interiors of tectonic plates . They are characteristically composed of ancient crystalline basement rock, which may be covered by younger sedimentary rock . They have a thick crust and deep lithospheric roots that extend as much as several hundred kilometres into the Earth's mantle . </P> <P> The term craton is used to distinguish the stable portion of the continental crust from regions that are more geologically active and unstable . Cratons can be described as shields, in which the basement rock crops out at the surface, and platforms, in which the basement is overlaid by sediments and sedimentary rock . </P> <P> The word craton was first proposed by the Austrian geologist Leopold Kober in 1921 as Kratogen, referring to stable continental platforms, and orogen as a term for mountain or orogenic belts . Later Hans Stille shortened the former term to kraton from which craton derives . </P>

What is the difference between a craton shield and platform
find me the text answering this question