Type Locality:

The type section (362 m thick) is located on the southwestern limb of Sapper Anticline northeast of central Nahanni pluton at lat. 62°42'N and long. 128°25.6'W (section 51). The name "Sapper" is derived from the Sapper Ranges, over which the formation outcrops extensively (Gordey and Anderson, 2000).

Distribution:

Mapped in the south part of the northeastern Niddery Lake map area (Cecile, 2000) and the southern Niddery Lake map area (Sd1 unit of Cecile and Abbott, 1992) and in the Nahanni map area (Gordey and Anderson, 1993) (Cecile, 2000).

Lithology:

The Sapper Formation comprises recessive, thin-bedded, dark grey to tan-orange weathering limestone and silty limestone exposed northeast of the South Nahanni River. In many areas two members are recognized, a lower limestone member of grey weathering, dark grey thin-bedded limestone and an upper silty limestone member of tan to tan-orange weathering silty limestone (Gordey and Anderson, 1993).

Relationship:

The Sapper Formation is easily distinguished at a distance from the underlying light grey to white weathering dolostone of the Haywire Formation and from grey weathering limestone of the overlying Grizzly Bear Formation. The lower contact with the Haywire Formation is abrupt and the upper contact with the Grizzly Bear Formation is sharp and unconformable. On the southwestern limb of Mararet Syncline the Grizzly Bear Formation is absent. There the Sapper Formation cannot be differentiated from the overlying Funeral Formation; the Sapper/Funeral contact is defined at a subtle change in from silty to shaly limestone. A subtle change in weathering colour from orange to bright orange also occurs at the contact. In the southwest of the Nahanni map area the Sapper Formation sharply and unconformably underlies the Portrait Lake Formation (Earn Group). The Whittaker, Delorme, Camsell, Sombre, and Arnica formations are equivalent to parts of the Sapper Formation. The Landry Formation is also a possible equivalent (Gordey and Anderson, 1993). In the Nahanni/southeast Niddery Lake map areas the Steel Formation is partly correlative with the Sapper Formation (see Gordey and Anderson, 1993; Norford et al., 1993; Abbott, 1983 (his Sd1 = Sapper Formation). The Hailstone Formation is time equivalent to parts of the Sapper Formation (Cecile, 2000).

References:

Abbott, J.G., 1983. Structure and Stratigraphy of the MacMillan Fold Belt: Evidence for Devonian Faulting. Exploration and Geological Services Division, Yukon Region, Indian and Northern Affairs Canada, Open File 1983-1, 16 p., 3 maps at 1:50 000 scale.

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., 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.

Gordey, S.P. and Anderson, R.G., 1993. Evolution of the northern Cordilleran miogeocline, Nahanni map area (105I), Yukon Territory and District of Mackenzie; Geological Survey of Canada, Memoir 428, 214 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.