Editing Canadian Shield (section)

{{Short description|Geographic and geologic area of North America}}
{{Infobox rockunit
| name           = Canadian Shield
| type           = [[Shield (geology)|Shield]]
| age            = {{Long fossil range|4500|540|[[Precambrian]]}}
| region         = [[North America]]
| country        = Canada<br />United States<br />Greenland
| unitof         = [[North American craton]]
| subunits       = [[Laurentian Upland]]<br />[[Kazan Region|Kazan]]<ref name=ca-atlas/>
| coordinates    = {{coord|52|00|N|71|00|W|region:CA_type:landmark_source:kolossus-cswiki|display=title,inline}}
| underlies      =
| overlies       =
| thickness      =
| extent         =
| area           = 8,000,000 km<sup>2</sup><ref name=britannica/>
| map            = Canada geological map.JPG
| map_caption    = The Canadian Shield is a broad region of Precambrian rock (pictured in shades of red) that encircles [[Hudson Bay]]. It spans eastern, northeastern, and east-central [[Canada]] and the [[Upper Midwest|upper midwestern]] [[United States]].
| namedfor       =
}}

The '''Canadian Shield''' ({{langx|fr|'''Bouclier canadien'''}} {{IPA|fr|buklje kanadjɛ̃|}}), also called the '''Laurentian Shield''' or the  '''Laurentian Plateau''', is a [[Shield (geology)|geologic shield]], a large area of exposed [[Precambrian]] [[Igneous rock|igneous]] and high-grade [[metamorphic rock]]s. It forms the [[Laurentia|North American Craton (or Laurentia)]], the ancient geologic core of the [[North America]]n continent. [[Glacial period|Glaciation]] has left the area with only a thin layer of [[soil]], through which exposures of igneous [[bedrock]] resulting from its long volcanic history are frequently visible.<ref name =EG>{{cite book |last1=Marshak |first1=Stephen |title=Essentials of geology |date=2009 |publisher=W.W. Norton |location=New York |isbn=978-0393932386 |edition=3rd}}</ref> 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 continental [[United States]].