Type Locality:

Christopher Peninsula on the northern coast of Ellef Ringnes Island.

Distribution:

One of the most continuous Mesozoic units in the Arctic Islands; extends from Ellesmere Island to Banks Island. Thickness varies considerably, reaching a maximum of 1,450 m in the vicinity of southern Axel Heiberg Island and thinning to approximately 100 m along the margins of the Sverdrup Basin. Lerand (1973) suggests the Christopher may thicken offshore from western Banks Island.

Locality Data:

Thickness(m): Minimum 100, Maximum 1450.

Lithology:

Dark colored marine shale with abundant calcareous concretions and minor siltstone, sandstone and limestone. The Christopher is essentially a shale within the axial part of the Sverdrup Basin, with lenses and tongues of sandstone and siltstone appearing towards the margins. On parts of Axel Heiberg, Ellesmere and Ellef Ringnes Islands, a prominent sandstone unit up to 100 m thick is present near the middle of the formation. The formation is informally divided into two members, the lower containing more siltstone and/or sandstone and larger concretions. Where the prominent sandstone unit is present, the lower member includes beds to the top of the sandstone. Locally the top of the upper member contains very thin beds of fine-grained, glauconitic sandstone transitional to the overlying Hassel sandstones. On northern Axel Heiberg Island, Christopher shales contain intercalated basalt flows. Abundant fossil wood is present in the lower member at Eglinton Island.

Relationship:

Conformably overlies the Isachsen Formation and is conformably overlain by the Hassel Formation; on northwestern Banks Island unconformably overlies Upper Devonian Weatherall Formation. A basaltic flow separates the Christopher Formation from the underlying Isachsen Formation north of Blaa Mountain, Ellesmere Island.

References:

Heywood, W.W., 1955. Arctic piercement domes: Canadian Institute of Mining and Metallurgy, Bulletin, vol. 48, pp. 59-64.

Heywood, W.W., 1957. Isachsen area, Ellef Ringnes Island, District of Franklin, Northwest Territories: Geological Survey of Canada, Paper 56-8, 36 p.

Lerand, M., 1973. Beaufort Sea, pp. 315-386: in McCrossan, R.G. (Ed.), Future Petroleum Provinces of Canada, Canadian Society of Petroleum Geologists, Memoir I, 720 p.