DCHP-2

Precambrian Shield Pre-Cambrian Shield DCHP-2 (October 2016)

• n. — Geography, Mining

  an area of ancient rock (see Image 1) encircling Hudson Bay and extending from the Arctic to the Great Lakes; also Canadian Shield or Laurentian Shield.

  Type: 4. Culturally Significant — The "Precambrian" supereon began 4.6 billion years ago, when the earth was formed, and ended with the emergence of multicellular organisms. The term "Cambrian" was first used in the 1830s to describe geological rock formations in Wales, known classically as Cambria (see OED-3, s.v. "Cambrian" (2)), and the term "Precambrian" derived from it (see OED-3, s.v. "Precambrian", the earliest attestations of which come 30 years after "Cambrian"). Although "Precambrian" was used earlier to describe various geological formations, Precambrian Shield is most frequent in Canada (see Chart 1), yet only by a slim margin compared with the US. The term bears cultural significance as it is one of the most important geological formations in Canada (see, e.g. the 1925 and 2013 quotations). The mineral richness of the Shield, for instance, has been a source of economic development since the early 20th century.

  See also: Canadian Shield  Great Lakes  Hudson Bay  Laurentian Shield