Canadian Shield or Laurentian Plateau (lôrĕn´chən), U-shaped region of ancient rock, the nucleus of North America, stretching N from the Great Lakes to the Arctic Ocean. Covering more than half of Canada, it also includes most of Greenland and extends into the United States as the Adirondack Mts. and the Superior Highlands. The first part of North America to be permanently elevated above sea level, it has remained almost wholly untouched by successive encroachments of the sea upon the continent. It is the earth's greatest area of exposed Archaean-age rock; the metamorphic rocks of which it is largely composed were probably formed in the Precambrian. Repeatedly uplifted and eroded, it is today an area of low relief (c.1,000–2,000 ft/305–610 m above sea level) with a few monadnocks and low mountain ranges (including the Torngat and Laurentian Mts.) probably eroded from the plateau during the Cenozoic era. During the Pleistocene epoch, continental ice sheets depressed the land surface (see Hudson Bay), scooped out thousands of lake basins, and carried away much of the region's soil. Drainage is generally very poor on the shield. The southern part of the shield has thick forests while the north is covered with tundra. The region is largely undeveloped but has great water-power potential and is a source of minerals, timber, and fur-bearing animals.
"Canadian Shield." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (October 23, 2017). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/canadian-shield
"Canadian Shield." The Columbia Encyclopedia, 6th ed.. . Retrieved October 23, 2017 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/canadian-shield
Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).
Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.
Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:
Modern Language Association
The Chicago Manual of Style
American Psychological Association
- Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
- In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.