Unit Name: Old Cabin Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Early Cambrian - Early Silurian (542 - 422.9 ma)
Age Justification: Stratigraphic relations. The Old Cabin Formation volcanics are no older than the Arrowhead Lake Member (Narchilla Formation) and are as young as the basal Steel Formation. Thus they can range in age from Early Cambrian to Early Silurian. Over most of the area they are mainly found with the Cambrian Gull Lake Formation and the bulk of volcanism is thought to be Cambrian. A single archeocyathid was identified within these volcanics by B.S. Norford (Norford et al., 1993) (Cecile, 2000).
Province/Territory: Yukon Territory

Originator: Cecile, 2000.

Type Locality:
The type area of the Old Cabin Formation is a solitary mountain complex between Old Cabin Creek, after which it is named, on the south, and the Rogue River on the north. This complex has a central peak of 2112 m at UTM co-ordinates 379450 E and 7067600 N, Zone 9, NTS 105-O/11. The mountain complex itself was described as the Old Cabin Massif by Hart (1986) (Cecile, 2000).

Distribution:
Occurs within the the Selwyn Basin. Mappable Old Cabin Formation volcanics are found in large synclinal structures and within the Gull Lake Formation in the western northeastern Niddery Lake map area (Cecile, 1997c, d), and throughout the northwestern Niddery Lake map area (Cecile, 1984a, 1998a, b, c, 1999; Cecile and Abbott, 1989, 1992). Hart (1986) reported that strata assigned to the type section are up to 500 m thick (Cecile, 2000).

Locality Data:
Thickness(m): Maximum 500.

Lithology:
Hart (1986) reported that strata from the type section assigned to the formation consist of hyaloclastic breccias with lesser amounts of massive and pillowed flows, lapilli tuffs, epiclastics, sills, and dikes. Hart also noted that they show evidence of intense low-temperature hydrothermal alteration with olivine and pyroxene pseudomorphed by hydrated phyllosilicates, quartz and carbonate (Cecile, 2000).

Relationship:
In the type area the Old Cabin Formation overlies the Gull Lake Formation argillite with a sharp contact, and is directly overlain by the upper Lower Silurian to Lower Devonian Steel Formation. To the northwest of the Niddery Lake map area (Cecile and Abbott, 1992), however, the Old Cabin Formation is in direct contact with the top of the Arrowhead Lake Member, Narchilla Formation and laterally intertongues with the Gull Lake Formation. Outside the type area the formation either intertongues with and/or forms distinct units within the Gull Lake, Hess River, Rabbitkettle and Elmer Creek formations. In limited areas it is directly overlain by strata of the Lower to Upper Ordovician Elmer Creek Formation. In the northeastern Niddery Lake map area most Old Cabin Formation units rest directly on the Gull Lake Formation and the upper contact is the modern-day erosion surface. West of Keele Peak, the Old Cabin Formation occurs as a distinct unit within the Gull Lake Formation and at the same locality the Gull Lake Formation features numerous units and beds of volcanic rocks. The precise stratigraphic relations in this area are obscured by intense foreshortening, with small-scale detachments, within the Rogue Décollement Complex. Blusson (1974) mapped similar volcanic occurrences as 'Proterozoic' volcanics in adjacent Bonnet Plum (106 B) and Nadaleen (106 C) map areas, north and northwest of the Niddery Lake map area. The uppermost parts of the Old Cabin Formation are correlative with the Marmot Formation, which outcrops in the northeast of the northeastern Niddery Lake map area, and over much of the Misty Creek Embayment to the north and northeast (Cecile, 1982; Goodfellow et al., 1995). Isolated occurrences of similar Cambrian and Lower Paleozoic volcanics are found throughout the Canadian Cordillera, and in Alaska (see Goodfellow et al., 1995) (Cecile, 2000).

History:
The type area of the Old Cabin Formation has been studied in detail by both Sarjeant (1983) and Hart (1986) (Cecile, 2000).

Remark:
The Old Cabin Formation volcanics represent discrete alkalic volcanic centres that are penecontemporaneous with deposition of the deep-water Gull Lake Formation, and to a lesser degree with the younger Elmer Creek and Steel formations. Most of the volcanics are probably of submarine origin - volaniclastics, flows, etc (Cecile, 2000).

References:
Blusson, S.L., 1974. Draft of five geological maps of Operation Stewart, northern Selwyn Basin, Yukon Territory and District of Mackenzie; Geological Survey of Canada, Open File 205.
Cecile, M.P., 1982. The lower Paleozoic Misty Creek Embayment, Selwyn Basin, Yukon and Northwest Territories; Geological Survey of Canada, Bulletin 335, 78 p.
Cecile, M.P., 1984a. Geology of northwest Niddery Lake (105-O/12,13,14); Geological Survey of Canada, Open File 1006.
Cecile, M.P., 1998a. Geology of Einarson Creek (NTS 105-O/13); Geological Survey of Canada, Map 1944A, Scale: 1:50 000.
Cecile, M.P., 1998b. Geology of Marmot Creek (NTS 105-O/14); Geological Survey of Canada, Map 1923A, Scale: 1:50 000.
Cecile, M.P., 1998c. Geology of Arrowhead Lake (NTS 105-O/11); Geological Survey of Canada, Map 1943A, Scale: 1:50 000.
Cecile, M.P., 2000. Geology of the northeastern Niddery Lake map area, east-central Yukon and adjacent Northwest Territories; Geological Survey of Canada, Bulletin 553, 120 p.
Cecile, M.P., and Abbott, J.G., 1989. Geology of the Niddery Lake map area (NTS 105-O); Geological Survey of Canada, Open File 2076.
Cecile, M.P., and Abbott, J.G., 1992. Geology of the Niddery Lake map area (NTS 105-O) at 1:250 000; Geological Survey of Canada, Open File 2465, 1 geological map (Scale 1:250 000) + 1 geological legend.
Goodfellow, W.D., Cecile, M.P., and Leybourne, M.I., 1995. Geochemistry, petrogenesis and tectonic setting of lower Paleozoic alkalic and potassic volcanic rocks, northern Canadian Cordilleran Miogeocline; Canadian Journal of Earth Sciences = Journal Canadien des Sciences de la Terre, vol. 32, pp. 1236-1254.
Hart, C.J.R., 1986. The geology of the Old Cabin Creek Massif, Selwyn Basin, Yukon Territory; B.Sc. Thesis, McMaster University, 111 p.
Norford, B.S., Orchard, M.J., Norris, A.W., Uyeno, T.T., Cecile, M.P., Abbott, J.G., Jackson, D.E., Fritz, W.H., Hofmann, H.J., Nowlan, G.S., and Tipnis, R.S., 1993. Paleontological identifications and correlations, Niddery Lake map area, NTS 105-O, and immediately adjacent map areas; Geological Survey of Canada, Open File 2682, 88 p.
Sarjeant, P.T., 1983. Petrology and textural analysis of the Wenchless Ridge volcanics, Old Cabin claims, Yukon Territory; B.Sc. Thesis, Queen's University.

Source: GEOLOGICAL SURVEY OF CANADA, CALGARY
Contributor: Michael Pashulka
Entry Reviewed: No
Name Set: Lithostratigraphic Lexicon
LastChange: 02 Dec 2010