Surficial geologic research program in the southern Mackenzie valley, Northwest Territories, Canada: its Significance and use in Planning Pipeline Construction and Resource Development

Surficial geologic research conducted by the Geological Survey of Canada in the southern Mackenzie Valley from 2005 to 2007 covered approximately 100,000 km2 and has yielded a large amount of geoscience data, including: surficial geology maps, till geochemistry, geotechnical analyses, drift isopach maps, stratigraphic correlations, and clast lithology-till provenance studies. In recognizing the pressing need for geoscience data in planning for the proposed Mackenzie Valley Gas Pipeline, the project has involved a wide variety of disciplines and each of these has produced published data in a variety of formats. Geological data is being published in digital format as: 1) Surficial geology maps placed on digital topography at a scale of 1:100 000; 2) Radarsat image maps; and 3) Landslide maps linked with a database. A CD-ROM will be produced containing all of the above mentioned maps, and in addition, will contain geochemical data, drift isopach (thickness) maps, and potential granular aggregate maps. Surficial geologic polygons will be linked to sites and their description, and are captured as figures showing stratigraphy accompanied by photographs, sample locations, lithology pie charts, and geochronological data where available. Sample numbers will be linked with geochemical data, geochronology reports, and macrofossil reports, etc. Of special significance to the pipeline and resource development is the detailed mapping of landslide data, which in some areas has been carried out up to 50 km east and west of the pipeline. Till, glaciolacustrine sediments and shale bedrock are the most common lithologies along the eastern boundaries of the Mackenzie Mountains and plains to the east: the area covered by this program. Here, postglacial stream incision reaches depths of over 100 metres. Landslide development is most common in areas of recent river and stream development and is widespread and active today, often changing the appearance of a landscape over the span of a single year.