Type Locality:

The type area for the originally defined "Elliot" Group is in the Quirke Lake-Elliot Lake area (Roscoe, 1957).

Distribution:

The Elliot Lake Group occurs at the base of the Huronian succession. The Huronian Supergroup occurs in a northerly-concave arcuate fold belt, 200 miles long and about 40 miles wide, in the Southern province, along the north shore of Lake Huron (Frarey and Roscoe, 1970).

Lithology:

The Elliot Lake Group at the base of the Huronian consists of a heterogeneous assemblage of vlocanics, turbiditic wacke, arkose, and conglomerate, inclduding uraniferous quartz pebble conglomerate. A succession of basalt flows and volcanogenic sediments as much as 2600 m thick (Elsie Mountain and Stobie formations), and rhyolite flows and pyroclastics (Copper Cliff Formation) up to 2600 m thick, forms the basal part of the group in the Sudbury area. In the western Huronian belt, the Thessalon Formation and correlative subaerial basalt formations up to 1000 m thick overlie a basal arkose unit (Livingstone Creek Formation) and are succeeded by subarkose of the Matinenda Formation. The McKim Formation, a pelite-wacke-quartz arenite unit at the top of the group which is as much as 3 km thick near Sudbury, thins westward and wedges out near Elliot Lake due partly to erosion prior to deposition of the unconformably overlying Hough Lake Group (Card and Jackson, 1995).

Age Determinations:

Method - U/Pb; Material - Zircon; Age - 2450; Err_Minus - 10; Err_Plus - 25..

Relationship:

The Huronian Supergroup succession has been subdivided into four groups (Roscoe, 1969; Robertson et al., 1969) in ascending order: Elliot Lake, Hough Lake, Quirke Lake, and Cobalt groups. The Elliot Lake Group contains volcanic rocks - the Thessalon, Elsie Mountain, Stobie and Copper Cliff Formations, feldspathic quartzite - the Matinenda and Livingstone Creek Formations, and argillaceous sediments - the McKim Formation. Successions within the group differ in various parts of the belt. Volcanics are widespread areally (Salmay Lake, Baldwin, Agnew Lake, and Pater are other informal names applied locally to volcanics of the Elliot Lake Group between Blind River and Sudbury), but are most abundant at the western and eastern ends (Frarey and Roscoe, 1970; Card and Jackson, 1995). The Huronian rocks unconformably overlie Archean basement rocks. The basal Ramsay Lake Formation of the Hough Lake Group conformably to disconformably overlies the McKim; locally in the north the Ramsay Lake rests unconformably on volcanic rocks of the Elliot Lake Group and on Archean basement (Card and Jackson, 1995).

History:

The Elliot Lake Group (originally Elliot Group), as defined in its type area (Roscoe, 1957), comprised the basal Matinenda Formation, mainly feldspathic quartzite, and the overlying Nordic Formation, mainly argillite. As a result of subsequent mapping and exploration drilling, volcanic rocks have also been recognized within the group at various places in the Huronian belt (Robertson et al., 1969; Card et al., 1971). Roscoe (1969, p. 49) later reclassified the Nordic Formation as McKim Formation (Frarey, 1977).

References:

Ames, D.E., Davidson, A., Buckle, J.L., and Card, K.D., 2005. Geology, Sudbury bedrock compilation, Ontario; Geological Survey of Canada, Open File 4570, 2 sheets.

Card, K.D. and Jackson, S.L., 1995. Tectonics and metallogeny of the early Proterozoic Huronian Foldbelt and the Sudbury Structure of the Canadian Shield; Geological Survey of Canada, Open File 3139, 55 pages.

Card, K.D., Donovan, J.F., Lovell, H.L., Lumbers, S.B., Meyn, H.D., Savage, W.S., Thomson, R., and Thomson, J.E., 1971. Sudbury-Cobalt Sheet; Ontario Department of Mines and Northern Affairs, Geological Compilation Series, Map 2188.

Frarey, M.J. and Roscoe, S.M., 1970 The Huronian Supergroup North of Lake Huron; p.143-157 in Symposium on Basins and Geosyncllnes of the Canadian Shield, edited by A.J. Baer; Geological Survey of Canada, Paper 70-40, 265p.

Frarey, M.J., 1977. Geology of the Huronian Belt between Sault Ste. Marie and Blind River, Ontario; Geological Survey of Canada, Memoir 383, 87 p.

Krogh, T.E., Davis, D.W., and Corfu, F., 1984. Chapter 20, Precise U-Pb Zircon and Baddeleyite Ages for the Sudbury Area; p. 431-447 in The Geology and Ore Deposits of the Sudbury Structure, edited by E.G. Pye, A.J. Naldrett, and P.E. Giblin, Ontario Geological Survey, Special Volume 1, 603 p.

Prevec, S.A., 1992. U-Pb constraints on early Proterozoic mafic magmatism from the southern Superior and western Grenville provinces, Ontario; In Radiogenic age and isotopic studies: report 6; Geological Survey of Canada, Paper 92-2, p. 97-106.

Robertson, J.A., Card, K.D., and Frarey, M.J., 1969. The Federal-Provincial Committee on Huronian Stratigraphy progress report; Ontatio Department of Mines, Miscellaneous Publication 31, 26 pp. (accompanied by correlation chart).

Roscoe, S.M., 1957. Geology and uranium deposits, Quirke Lake-Elliot Lake, Blind River, Ontario; Geological Survey of Canada Paper 56-7, 21 pp.

Roscoe, S.M., 1969. Huronian rocks and uraniferous conglomerates; Geological Survey of Canada, Paper 68-40, 205 pp.