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TitleProposals for time classification and correlation of precambrian rocks and events in Canada and adjacent areas of the Canadian Shield part 1 : a time classification of precambrian rocks and events
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LicencePlease note the adoption of the Open Government Licence - Canada supersedes any previous licences.
AuthorStockwell, C H
SourceGeological Survey of Canada, Paper no. 80-19, 1982, 135 pages (6 sheets), https://doi.org/10.4095/109353 (Open Access)
Year1982
PublisherGeological Survey of Canada
Documentserial
Lang.English
MapsPublication contains 4 maps
Map Info.geological, 1:10,000,000
Mediapaper; on-line; digital
RelatedThis publication is related to Douglas, R J W; (1980). Proposals for time classification and correlation of precambrian rocks and events in Canada and adjacent areas of the Canadian Shield, part 2: a provisional standard for correlating precambrian rocks, Geological Survey of Canada, Paper no. 80-24
File formatpdf
ProvinceBritish Columbia; Alberta; Saskatchewan; Manitoba; Ontario; Quebec; New Brunswick; Nova Scotia; Prince Edward Island; Newfoundland and Labrador; Northwest Territories; Yukon; Nunavut
NTS1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65; 66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560
Subjectsgeochronology; geological time scale; Precambrian
Released1982 03 01; 2016 03 11
AbstractPrecambrian time is subdivided on the basis of periods of orogenic activity as displayed mainly in the Canadian Shield. Commonly each orogeny is followed unconformably by the deposition of sedimentary and volcanic rocks. The time boundaries chosen are natural ones that separate basement from unconformably overlying rocks. To achieve this, boundaries between time units are drawn at the close of the last orogeny of the basement and are defined in type regions which serve as standards r or reference. Isotopie age determinations are used to date, as accurately as possible, the geologically defined time boundaries in type regions but present estimates may be revised as more information becomes available. Isotopie ages are also used for arranging the several tirne units in chronological order, for placing sedimentary and volcanic rock and anorogenic intrusions into their appropriate time units, and for long range correlation. All Precambrian time is divided into two main units called the Archean and Proterozoic with the boundary between them defined by the close of the Kenoran Orogeny presently estimated at about 2500 Ma. The Archean is divided into four informal units, the oldest ending about 3400-3500 Ma ago. The Proterozoic is divided into three formal units called the Aphebian, the H elikian, and the Hadrynian with boundaries between them defined, respectively, by the close of the Hudsonian Orogeny at about 1750 Ma and by the close of the Grenvillian Orogeny at about 1000 Ma. Each of the se Proterozoic units is further divided into two or three time units, mostly informal.
GEOSCAN ID109353