Type Locality:

No complete section of the Mackenzie Mountains Supergroup exists in the Mackenzie Mountains, and so a composite stratotype is proposed (Fig. 2), consisting of the type section of the Tabasco Formation in NTS 96D, the type section of the Tsezotene Formation in NTS 95M (63°24’N / 126°40’W; Gabrielse et al. 1973, section G1), the principal reference section of the Katherine Group in NTS 95L (62°38’N / 126°32’W; Gabrielse et al., 1973, Section G2 = Section 022 in appendix), and the type sections of the seven formations of the Little Dal Group, all of which are described by Long and Turner (2012).

Distribution:

As defined by Long and Turner (2012), the Mackenzie Mountains Supergroup is exposed in the Mackenzie Mountains, Northwest Territories, from 62°20’ to 65°30’N and 126°00’ to 134’30’W . Parts of the supergroup have been tentatively correlated with strata as far west as Alaska, and as far to the northeast as the Minto Inlier of Victoria Island (Long et al., 2008). At least part of the Mackenzie Mountains Supergroup is presumed to be present in the subsurface west of the Plateau fault, and the basal contact of the supergroup and direct equivalents of its lowest strata are exposed in the Wernecke Mountains (YT; Turner, 2011) as units formerly included in the upper part of the Pinguicula Group (Eisbacher, 1981). Putative equivalents are exposed in the Ogilvie Mountains (Abbott, 1997b; Thorkelson et al., 1998, 2001, 2005; Long et al., 2008). Seismic data indicate that equivalent rocks are locally present in the subsurface of the interior plains east of the Mackenzie Mountains (Cook and MacLean, 2004).

Lithology:

The Mackenzie Mountains Supergroup is defined by Long and Turner (2012) to include carbonate rocks of the Tabasco Formation, mudstones, sandstones and minor carbonate rocks of the Tsezotene Formation, sandstones, mudstones and carbonate rocks of the Katherine Group, and carbonate rocks, evaporite rocks and mudstones of the Little Dal Group.

Relationship:

According to Long and Turner (2012) the Mackenzie Mountains Supergroup unconformably overlies weakly deformed strata of the Pinguicula Group in the Wernecke Mountains (Thorkelson, 2000; Thorkelson et al., 2005, Turner, 2011), but its base is not exposed in the Mackenzie Mountains. The supergroup underlies volcanic rocks known as the "Little Dal basalt" and strata of the Coates Lake Group in the Mackenzie Mountains.

History:

Young et al. (1979, 1982) proposed that Proterozoic strata in western and northern Canada be divided into three major unconformity-bounded packages (sequences A, B and C), of approximately Mesoproterozoic, early Neoproterozoic, and late Neoproterozoic respectively. Strata of sequence B that underlie the Coates Lake Group in the Mackenzie Mountains were informally named the Mackenzie Mountains supergroup (Young et al., 1979). Strata of the Mackenzie Mountains Supergroup are overlain unconformably by a succession of locally preserved volcanic strata (the “Little Dal basalt”) and siliciclastic and carbonate rocks of the Coates Lake Group. Jefferson (1983), and Jefferson and Ruelle (1986) included these latter units in the informal Mackenzie Mountains supergroup, whereas others (Aitken, 1981; Morris and Aitken, 1982; Park and Aitken, 1986a, 1986b; Aitken and McMechan, 1991; Narbonne and Aitken, 1995; Thorkelson et al., 2005; Long et al., 2008; Turner and Long, 2008) considered them to be part of the overlying Windermere Supergroup. An alternate view presented by Jefferson and Parrish (1989), placed the “Little Dal basalt” in the Mackenzie Mountains supergroup, but excluded the Coates Lake Group from either supergroup, as did Jefferson and Colpron (1998). Long and Turner (2012) return to the usage of Narbonne and Aitken (1995), Thorkelson et al. (2005), Long et al. (2008) and Turner and Long (2008), in excluding the “Little Dal basalt” and Coates Lake Group from the Mackenzie Mountains Supergroup.

References:

Abbott, J.G., 1997b. Geology of the Upper Hart River Area, eastern Ogilvie Mountains, Yukon Territory (116A/10, 116A/11). Exploration and Geological Services Division, Yukon Region, Indian and Northern Affairs Canada, Bulletin 9, 92 p.

Aitken, J.D., 1981. Stratigraphy and sedimentology of the upper Proterozoic Little Dal Group, mackenzie Mountains, Northwest Territories; in Proterozoic Basins of Canada, (ed.) F.H.A. Campbell; Geological Survey of Canada, Paper 81-10, p. 47-71.

Aitken, J.D., and McMechan, M.E., 1991. Middle Proterozoic assemblages, Chapter 5 in H. Gabrielse and C.J. Yorath (editors), Geology of the Cordilleran Orogen in Canada; Geological Survey of Canada, Geology of Canada 4, p. 97-124.

Cook, D.G., and MacLean, B.C., 2004. Subsurface Proterozoic stratigraphy and tectonics of the western plains of the Northwest Territories. Geological Survey of Canada Bulletin 575.

Eisbacher, G.H., 1981. Sedimentary tectonics and glacial record in the Windermere Supergroup, Mackenzie Mountains, northwestern Canada; Geological Survey of Canada, Paper 80-27, 40 p.

Jefferson, C.W. and Parrish, R., 1989. Late Proterozoic stratigraphy, U-Pb zircon ages, and rift tectonics, Mackenzie Mountains, northwestern Canada; Canadian Journal of Earth Sciences, v. 26, p. 1784-1801.

Jefferson, C.W. and Ruelle, J.C.L., 1986. The Late Proterozoic Redstone Copper Belt, Mackenzie Mountains, N.W.T.; In Mineral Deposits of the Northern Cordillera, J.A. Morin (ed.); Canadian Institute of Mining and Metallurgy, Special Volume 37, p. 154-168.

Jefferson, C.W., 1983. The Upper Porterozoic Redstone Copper Belt, Mackenzie Mountains, Northwest Territories; unpublished Ph.D thesis, University of Western Ontario, London, Ontario, 445 p.

Jefferson, C.W., and Colpron, M., 1998. Geology of the Coppercap Mountain area, Mackenzie Mountains, Northwest Territories (NTS 95 L/10). NWT Geology Division, Indian and Northern Affairs Canada, EGS Open File 1998-04, 1 map, 1:50,000 scale.

Leslie, C.D., 2009. Detrital zircon geochronology and rift-related magmatism: central Mackenzie Mountains, Northwest Territories. M.Sc. thesis, University of British Columbia, Vancouver, BC, 224 p.

Long, D.G.F. and Turner, E.C., 2012. Formal definition of the Neoproterozoic Mackenzie Mountains Supergroup (NWT), and formal stratigraphic nomenclature for terrigenous clastic units of the Katherine Group. Geological Survey of Canada Open File 7113.

Long, D.G.F., R.H. Rainbird, R.H., Turner, E.C., and MacNaughton, R.B., 2008. Early Neoproterozoic Strata (Sequence B) of mainland Northern Canada and Victoria and Banks Islands: a contribution to the Geological Atlas of the Northern Canadian Mainland Sedimentary Basin. Geological Survey of Canada, Open File 5700.

Morris, W.A. and Aitken, J.D., 1982. Paleomagnetism of the Little Dal Lavas, Mackenzie Mountains, Northwest Territories, Canada. Canadian Journal of Earth Sciences 19: 2020-2027.

Narbonne, G.M., and Aitken, J.D., 1995. Neoproterozoic of the Mackenzie Mountains, northwestern Canada. Precambrian Research 73: 101–121.

Park, J.K., and Aitken, J.D., 1986a. Paleomagnetism of the late Proterozoic Tsezotene Formation of northwestern Canada. Journal of Geophysical Research 91 (B5): 4955-4970.

Park, J.K., and Aitken, J.D., 1986b. Paleomagnetism of the Katherine Group in the Mackenzie Mountains; implications for post-Grenville (Hadrynian) apparent polar wander. Canadian Journal of Earth Sciences 23: 308-323.

Thorkelson, D.J., 2000. Geology and mineral occurrences of the Slats Creek, Fairchild Lake and ‘Dolores Creek’ areas, Wernecke Mountains (106D/16, 106C/13, 106C/14), Yukon Territory. Exploration and Geological Services Division, Yukon, Indian and Northern Affairs Canada, Bulletin 10, 73 p.

Thorkelson, D.J., Abbott, J.G., Mortensen, J.K., Creaser, R.A., Villeneuve, M.E., and McNicoll, V.J., 2005. Early and middle Proterozoic evolution of Yukon, Canada; the Lithoprobe Slave-NORthern Cordillera lithospheric evolution (SNORCLE) transect. Canadian Journal of Earth Sciences 42: 1045-1071.

Thorkelson, D.J., Abbott, J.G., Mortensen, J.K., Creaser, R.A., and Villeneuve, M.E.,1998. Proterozoic sedimentation, magmatism, metasomatism and deformation in the Wernecke and Ogilvie mountains, Yukon. In F. Cook and P. Erdmer (Eds.), Slave- Northern Cordillera Lithospheric Evolution (SNORCLE) and Cordilleran tectonics workshop. Lithoprobe Report 64: 110-119.

Thorkelson, D.J., Mortensen, J.K.. Davidson, G.J., Creaser, R.A., Perez, W.A., and Abbott, J.G., 2001. Early Mesoproterozoic intrusive breccias in Yukon, Canada; the role of hydrothermal systems in reconstructions of North America and Australia. Precambrian Research 111: 31-55.

Turner E.C., and Long, D.G.F., 2008. Syndepositional fault activity during deposition of the Neoproterozoic Mackenzie Mountains Supergroup, N.W.T., Canada: Implications for evolution of the Mackenzie Basin and the Mackenzie Mountains Zn District. Canadian Journal of Earth Sciences 45: 1159-1184.

Turner, E.C., 2011. Stratigraphy of the Mackenzie Mountains supergroup in the Wernecke Mountains, Yukon. In: Yukon Exploration and Geology 2010, K.E. MacFarlane, L.H. Weston and C. Relf (eds.), Yukon Geological Survey, p. 207-231.

Young, G.M., Jefferson, C.W., Delaney, G.D., and Yeo, G.M., 1979. Middle and late Proterozoic evolution of the northern Canadian Cordillera and Shield; The Geological Society of America (GSA), Geology, vol. 7, no. 3 (March), pp. 125-128.

Young, G.M., Jefferson, C.W., Long, D.G.F., Delaney, G.D., and Yeo, G.M., 1982. Upper Proterozoic stratigraphy of northwestern Canada and Precambrian history of the North American Cordillera: Society of Economic Geologists Coeur d'Alene Field Conference, Idaho Bureau of Mines Bulletin 24, pages 73-96.