Unit Name: Rabbitkettle Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Late Cambrian - Early Ordovician (499 - 471.8 ma)
Age Justification: Fossils are scarce. Only in a single section near headwaters of Broken Skull River are trilobites abundant. Here the Cambrian-Ordovician boundary (base of Missisquoia Zone) occurs some 60 m (197 ft) below top of Rabbitkettle Formation. In the equivalent RRal division of Road River Formation, Fritz (pers. comm. 1979) has identified the Dunderbergian or Elvinia zone, the Elvinia, the Conaspis; and the Ptychaspis-Prosaukia or Saukia faunal zones. In the upper part of the same unit, Tipnis et al. (1978), has identified latest Tremadocian or basal Arenigian conodonts and Norford (pers. comm., 1979) has identified the Ordovician arthropod Caryocaris.
Province/Territory: Northwest Territories; Yukon Territory
Originator: Gabrielse et al., 1973.
Type Locality:
Type area near headwaters of Rabbitkettle River, Ragged Range, District of Mackenzie.
Distribution:
Nahanni map-area (105-I) southeastwardly to Coal River map-area (95-D). No complete section through the formation has been found. In the type area, it is greater than 1,200 m (3,900 ft) thick.
Lithology:
Well-bedded to massive, silty limestones and calcareous siltstones characterized by wavy banding. Also finely laminated dark grey to black argillaceous limestones and calcareous shales.
Relationship:
Unconformably overlies Lower Cambrian to Hadrynian units. Conformably overlain by Road River Formation in Selwyn Mountains near headwaters of Broken Skull River. Unconformably overlain by Road River Formation near Flat River. Probably equivalent to Broken Skull Formation to the east. Equivalent to the RRal division of the Road River Formation in the Bonnet Plume, Sekwi and Mount Eduni map-areas, southwestern Mackenzie Mountains (Cecile, pers. comm., 1979). The RRal unit is a 400-800 m (1,312-2,625 ft) succession of thin-bedded argillaceous limestones (Cecile, 1978).
Other Citations:
Blusson, 1968; Ludvigsen, 1982.
References:
Blusson, S.L., 1968. Geology and tungsten deposits near the headwaters of Flat River, Yukon Territory and southwestern District of Mackenzie, Canada; Geological Survey of Canada, Paper 67-22, 77 p.
Cecile, M.P., 1978. Report on Road River stratigraphy and the Misty Creek Embayment, Bonnet Plume (106B) and surrounding map-areas, N.W.T.; in, Current research, Part A, Blackadar, R.G., Griffin, P.J., Dumych, H., and Irish, E.J.W. (Eds. and Compilers); Geological Survey of Canada, Paper 78-1A, pp. 371-377.
Gabrielse, H., Blusson, S.L., and Roddick, J.A., 1973. Geology of the Flat River, Glacier Lake and Wrigley Lake map-areas, District of Mackenzie and Yukon Territory; Geological Survey of Canada, Memoir 366 (Parts I and II), 421 p.
Ludvigsen, R., 1982. Upper Cambrian and Lower Ordovician Trilobite Biostratigraphy of the Rabbitkettle Formation, Western District of Mackenzie; Royal Ontario Museum, Life Sciences Contributions, 134, 188 p.
Tipnis, R.S., Chatterton, B.D.E., and Ludvigsen, R., 1978. Ordovician conodont biostratigraphy of the southern District of Mackenzie, Canada; pp. 39-91: in Stelck, C.R. and Chatterton, B.D.E. (eds.), Western and Arctic Canadian Biostratigraphy, Geological Association of Canada, Special Paper no. 18, 602 p.
Source: CSPG Lexicon of Canadian Stratigraphy, Volume 2, Yukon Territory and District of Mackenzie; L.V. Hills, E.V. Sangster and L.B. Suneby (editor)
Contributor: R. Ludvigsen; M.P. Cecile
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 01 Dec 2010