Type Locality:

Along the east side of the Wind River near its mouth (65° 47-50'N, 135° 12-17'W).

Distribution:

Mountjoy (1967a) reported a thickness of over 1,500 m (5,000 ft), however, re-evaluation by Norris and Hopkins (1997) would suggest that it is much thinner. The formation is restricted to the Bonnet Plume Basin.

Lithology:

Predominantly medium- to coarse-grained cross-bedded, light grey to dark brown, carbonaceous sandstone with minor thin lenses of fine pebble conglomerate, shale and lignite (mostly in upper part). Individual sandstone units are 3-20 m (10-70 ft) thick. More than 180 m (600 ft) of quartz and chert pebble conglomerate occurs at the base of the formation on the Wind River. Norris and Hopkins (1977) divided the formation into two informal mappable units, the lower and upper Bonnet Plume Formation. The lower unit comprises relatively resistant conglomerate beds and includes units 1 to 6 of Mountjoy's type section and corresponds to Rouse and Srivastava (1972) Palynomorph Zone 1 of Mid to Late Albian. The upper Bonnet Plume Formation consists of sandstone, shale and lignite (units 7 to 58 of Mountjoy (1967a) and Palynomorph Zones 2-3 of Rouse and Srivastava (1972) of Maastrichtian to Paleocene age).

Relationship:

According to Mountjoy (1967a) it unconformably overlies Permian and older strata. Norris and Hopkins (1977) report that it overlies the Road River Fm on the Wind River. It is unconformably overlain by Quaternary deposits.

References:

Mountjoy, E.W., 1967a. Upper Cretaceous and Tertiary stratigraphy, northern Yukon Territory and northwestern District of Mackenzie; Geological Survey of Canada, Paper 66-16, 70 p.

Norris, D.K. and Hopkins, W.S., 1977. The geology of the Bonnet Plume Basin, Yukon Territory; Geological Survey of Canada, Paper 76-8, 20 p.

Rouse, Glenn E. and Srivastava, Satish K., 1972. Palynological Zonation of Cretaceous and Early Tertiary Rocks of the Bonnet Plume Formation Northeastern Yukon, Canada; Canadian Journal of Earth Sciences = Journal Canadien des Sciences de la Terre, vol. 9, no. 9 (September), pp. 1163-1179.