Precambrian Geology of Northeastern Alberta (NTS 74M, 74L and part of 74E)

This is a digital compilation at 1:250,000 scale of the Precambrian geology of the Alberta portion of the Canadian Shield and Athabasca Basin.

For the Alberta shield, the compilation is at 1:31,680 scale and based on detailed mapping by Alberta Geological Survey during 1958 and 1987. Between 1994 and 2000, the Geological Survey of Canada remapped a large portion of the Alberta shield at 1:50,000 scale and published the results as preliminary 'open file' and 'A series' maps. Modern geochronological studies and interpretations presented in several journal articles aided the mapping effort. The compilation also includes a series of updates derived from the author's fieldwork and analytical (geochemical and isotope) data collected and published between 2004 and 2009.

The compilation integrated all existing isotope data. Locations of uranium-lead and 40 argon/39 argon samples are marked on the map, and the tables summarize the age data. The legend displays samarium-neodymium time-of-depleted mantle model ages and epsilon values as ranges of variations for all map units that benefited from such analyses.

The author attempted to present the geological information on the Alberta shield in a neutral manner, unbiased by the three, mutually exclusive, regional tectonic concepts existing at the time of the compilation.

For the Athabasca Basin, the compilation is based on results from stratigraphic studies that Alberta Geological Survey and the Geological Survey of Canada sponsored from 2000 to 2006. These results were published in the last version of the geology of the Athabasca Basin presented in the ExTech IV volume, which the Geological Survey of Canada and Saskatchewan Geological Survey published in 2007. Brief overviews of the geology of the Alberta shield and Athabasca Basin are in the map's descriptive notes.