Type Locality:

Type section for the Road River formation (Jackson and Lenz, 1962) occurs on the north bank of a tributary of the Road River, approx. 66°44'N, 135°46'W, Yukon. Base of type section is faulted.

Distribution:

The Road River Group is an extensive lithostratigraphic unit recognized from the Halfway River map area (94B) (Thompson, 1989) northwestward to the Selwyn Basin in the Yukon (Gordey, 1981; Cecile, 1982) (Pyle et al., 2003). It varies in thickness and has been described from the Yukon, east-central Alaska and northeastern British (Jackson and Lenz in Hills et al., 1981) (Pyle and Barnes, 2000).

Lithology:

A succession of dark graptolitic shale, argillaceous limestone, and minor chert, dolostone, siltstone, and sandstone (Pyle et al., 2003).

Relationship:

In the Selwyn Basin (Selwyn Mountains), the Road River Group consists of, from oldest to youngest, the Duo Lake/Elmer Creek, and Steel formations. It is underlain by the Rabbitkettle Formation and overlain by the Portrait Lake Formation (Earn Group). In the Kechika Trough, the Road River Group consists of, from oldest to youngest, the Ospika, Pesika, Kwadacha, and Deserters formations. It is underlain aburptly and conformably or unconformably by the Kechika Formation and overlain unconformably by the Gunsteel formation (Earn Group) (Goodfellow, 2007; Pyle et al., 2003; Pyle and Barnes, 2000). In the Mackenzie Mountains, the Road River includes Cambrian strata and its lower member is equivalent to the Rabbitkettle and Kechika formations (Hills et al., 1981). The Road River in northeastern British Columbia is therefore partly equivalent to the Road River in the Selwyn Basin. In northeastern British Columbia, it is equivalent with the Skoki, Beaverfoot and Nonda to the east and in the southern Rockies, to the Glenogle Formation (Pyle and Barnes, 2000).

History:

The Road River Formation was named by Jackson and Lenz (1962) with a type section in the Richardson Mountains (Richardson Trough), northern Yukon. It is a thick succession (over 910) of dark graptolitic shale, argillaceous limestone and minor chert, dolostone, siltstone, and sandstone. It varies in thickness and has been described from the Yukon, east-central Alaska and northeastern British Columbia (Jackson and Lenz in Hills et al., 1981). In the Selwyn Basin and Richardson Trough, the Road River has been mapped during many studies such as those by Blusson (1974), Aitken et al. (1973b), Gabrielse et al. (1973), and Cecile (1978, 1982) (see Jackson and Lenz in Hills et al., 1981 for review). The name Road River was extended to northern British Columbia by Gabrielse (1975) in the Mesilinka (94E) map area and by Gabrielse et al. (1977) and Gabrielse (1981) in the Ware (94F) map area. It has been mapped as a group of undivided, informally named units in the McDame and Cry Lakes (Gabrielse, 1962c, 1963) and referred to as a Group in the Kechika map area (MacIntyre, 1992; Ferri et al., 1995, 1996, 1997). Similarly, the name Road River Group has since been used as a catch-all for several mappable units of Middle Ordovician to Middle Devonian basinal strata in the Halfway River map area (Thompson, 1989). The Road River was raised to group level and its base redefined by Fritz (1985) at a level in the Lower Cambrian (Pyle and Barnes, 2000). Friz (1985) proposed that that the base of the Road River Group be placed at the the base of Middle Cambrian strat in the type area of the Road River Formation and in the area of the Misty Creek Embayment and then stepped upward to the top of Rabbitkettle in Selwyn Basin and areas farther south (Cecile, 2000).

Remark:

Fritz (1985) raised the Road River to group level and redefined its base at a level in the Early Cambrian (Pyle et al., 2003).

References:

Aitken, J.D., Macqueen, R.W., and Usher, J.L., 1973b. Reconnaissance studies of Proterozoic and Cambrian stratigraphy, lower Mackenzie River area (Operation Norman), District of Mackenzie; Geological Survey of Canada, Paper 73-9, 178 p.

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., 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.

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., 2000. Geology of the northeastern Niddery Lake map area, east-central Yukon and adjacent Northwest Territories; Geological Survey of Canada, Bulletin 553, 120 p.

Ferri, F., Nelson, J. and Rees, C. 1995. Geology and mineralization of the Gataga River area, northern Rocky Mountains (94L/7, 8, 9 and 10); B.C. Ministry of Energy, Mines and Petroleum Resources, Geological Fieldwork 1994, Paper 1995-1, p. 277-295.

Ferri, F., Nelson, J., Rees, C., and Legun, A., 1997. Geology of the Northern Keckika Trough (NTS 94L/14, 15; 94M/3, 4, 5, 6, 12, 13; 104P/8, 9, 15, 16); B.C. Ministry of Energy, Mines and Petroleum Resources, Geological Fieldwork 1996, Paper 1997-1, p. 137-145.

Ferri, F., Rees, C., and Nelson, J., 1996. Geology and mineralization of the Gataga Mountain area, northern Rocky Mountains (94L/10, 11, 14 and 15); B.C. Ministry of Energy, Mines and Petroleum Resources, Geological Fieldwork 1995, Paper 1996-1, p. 137-154.

Fritz, W.H., 1985. The basal contact of the Road River Group - a proposal for its location in the type area and in other selected areas in the Northern Canadian Cordillera, in, Current Research, Part B,Regional Geology, Cordilleran Region; Geological Survey of Canada, Paper 85-1B, pp. 205-215.

Gabrielse, H., 1962c. Geology, Cry Lake, British Columbia; Geological Survey of Canada, Preliminary Map 29-1962, Scale: 1 Inch to Four Miles (1:253 440).

Gabrielse, H., 1963. McDame map-area, Cassiar District, British Columbia; Geological Survey of Canada, Memoir 319, 138 p.

Gabrielse, H., 1975. Geology or Fort Grahame (east half) map-area, British Columbia; Geological Survey of Canada, Paper 75-33, 28 p. (this publication contains Geological Survey of Canada, map 2-1975).

Gabrielse, H., 1981. Stratigraphy and structure of Road River and associated strata in Ware (west half) map area, northern Rocky Mountains, British Columbia; In: Current Research, Part A, Geological Survey of Canada, Paper 31-1A, p. 201-207.

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.

Gabrielse, H., Dodds, C.J., Mansy, J.L., and Eisbacherig, H., 1977. Geology of Toodoggone (94E) and Ware (94W/2) map-areas, British Columbia; Geological Survey of Canada, Open File Report 483, geologic map; 1:250,000, 1 sheet

Goodfellow, W.D., 2007. Base metal metallogeny of the Selwyn Basin, Canada; in, Goodfellow, W.D., ed., Mineral Deposits of Canada: A Synthesis of Major Deposit-Types, District Metallogeny, the Evolution of Geological Provinces, and Exploration Methods: Geological Association of Canada, Mineral Deposits Division, Special Publication No. 5, p. 553-579.

Gordey, S.P., 1981. Stratigraphy, structure and tectonic evolution of southern Pelly Mountains in the Indigo Lake area, Yukon Territory; Geological Survey of Canada, Bulletin 318, 44 p.

Hills, L.V., Sangster, E.V., and Suneby, L.B., 1981. Lexicon of Canadian Stratigraphy, Volume 2, Yukon Territory and District of MacKenzie: Canadian Society of Petroleum Geologists, 240 p.

Jackson, D.E. and Lenz, A.C., 1962. Zonation of Ordovician and Silurian graptolites of northern Yukon, Canada; American Association of Petroleum Geologists (AAPG), AAPG Bulletin, vol. 46, no. 1 (January), pp. 30-45.

MacIntyre, D.G., 1992. Geological setting and genesis of sedimentary exhalative barite and barite-sulfide deposits, Gataga District, northeastern British Columbia; Exploration and Mining Geology, v. 1, p. 1-20.

Pyle, L.J. and Barnes, C.R. 2000. Upper Cambrian to Lower Silurian stratigraphic framework of platform-to-basin facies, northeast British Columbia; Bulletin of Canadian Petroleum Geology, v. 48, p. 123-149.

Pyle, L.J., Orchard, M.J., Barnes, C. R., and Landry, M.L., 2003. Conodont biostratigraphy of the Lower to Middle Devonian Deserters Formation (new), Road River Group, northeastern British Columbia; Canadian Journal of Earth Sciences, vol. 40, no. 1, p. 99-113.

Thompson, R.I., 1989. Stratigraphy, tectonic evolution and structural analysis of the Halfway River maparea (94B), northern Rocky Mountains, British Columbia; Geological Survey of Canada, Memoir 425, pp. 1-119.