Shield (geology)
From Freepedia
(Redirected from Shield (geography))
Image:World geologic provinces.jpg
A shield is a large area of exposed basement rocks of continental crust, part of craton.
Shields are typically composed of Precambrian metamorphic and igneous rocks. Shields are part of tectonically stable areas called cratons. Shields are usually surrounded by platforms. Shields often - but not always - lie in the interior of a continent, such as the Canadian Shield, Baltic Shield, and the Arabian-Nubian Shield. Shields are generally stable, with few earthquakes or volcanoes. Shields have no active orogenic belts. The term, in this sense, was translated from German schild by H. B. C. Sollas in Suess's Face of Earth in 1901.
See also
