Canadian Shield
Channel: all the knowledge of the universe PRINCIPIA
Date: 2021-12-09

Canadian Shield, by Wikipedia https://en.wikipedia.org/wiki?curid=6230 / CC BY SA 3.0

#Cratons
#Geology_of_North_America
#Precambrian_North_America
#Regional_geology
#Geology_of_Canada
#Geology_of_the_United_States
#Precambrian_Canada
#Precambrian_United_States
#Stratigraphy_of_Canada
#Stratigraphy_of_the_United_States
The Canadian Shield （French: Bouclier canadien [buklje kanadjɛ̃]）, also called the Laurentian Plateau, is a large area of exposed Precambrian igneous and high-grade
metamorphic rocks （geologic shield） that forms the ancient geologic core of the North American continent （the North American Craton or Laurentia）.
Glaciation has left the area with only a thin layer of soil, through which the composition of igneous rock resulting from long volcanic history is frequently visible.
As a deep, common, joined bedrock region in eastern and central Canada, the Shield stretches north from the Great Lakes to the Arctic Ocean,
covering over half of Canada and most of Greenland; it also extends south into the northern reaches of the United States.
Human population is sparse and industrial development is minimal, but mining is prevalent.
The Canadian Shield is a physiographic division comprising four smaller physiographic provinces: the Laurentian Upland, Kazan Region, Davis and James.
The shield extends into the United States as the Adirondack Mountains （connected by the Frontenac Axis） and the Superior Upland.
The Canadian Shield is a U-shaped subsection of the Laurentia craton signifying the area of greatest glacial impact （scraping down to bare rock） creating the thin soils.
The Canadian Shield is more than 3.
96 billion years old.
The Canadian Shield once had jagged peaks, higher than any of today's mountains, but millions of years of erosion have changed these mountains to rolling hills.
The Canadian Shield is a collage of Archean plates and accreted juvenile arc terranes and sedimentary basins of the Proterozoic Eon that were progressively amalgamated during t...