Unit Name: Neruokpuk Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Late Proterozoic - Middle Devonian (900 - 385.3 ma)
Age Justification: Trilobites, graptolites and brachiopods.
Province/Territory: Yukon Territory; Alaska

Originator: Leffingwell, 1919.

Type Locality:
Typically developed on three sides of Lake Peters and near the forks of the Canning River, Alaska.

Approximately 2,438 m (8,000 ft) but could be several times greater. The formation occurs in the eastern Brooks Range Alaska and the British and Barns mountains in the Yukon.

Chiefly quartzite schist (Leffingwell, 1919). Brosgé et al. (1962) subdivided it in the eastern Brooks Range into four units listed in ascending order: 1) Quartzite-schist unit; 2) Limestone unit; 3) Limestone-phyllite unit, 4) Phyllite-chert unit. Reiser et al. (1971) modified this sequence slightly noting the volcanic flows and pyroclastics in units 2 and 3. Miall (1973) extended the terminology into the British and Barn mountains in the Yukon where the sequence is essentially the same as that described by Brosgé et al. (1962). Note there is an unconformity between units 3 and 4.

According to Leffingwell (1919) the Neruokpuk is overlain by black shales of Mississippian or Devonian age followed by the Lisburne Limestone (now Group). In the British and Barns mountains it is overlain unconformably by the Kayak Fm. The Neruokpuk correlates, at least in part, with the Road River Gp.

Other Citations:
Adkison and Brosgé, 1970; Bamber, 1972; Brosgé et al., 1962; Dutro et al., 1972; Gabrielse, 1967; Kupsch, 1973; Leffingwell, 1919; Lenz and Perry, 1972; Miall, 1973; Reiser et al., 1971.

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: L.V. Hills; A.D. Miall
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 29 Jun 2004