Unit Name: Amadjuak Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Edenian - Maysvillian (454 - 447.5 ma)
Age Justification: Biostratigraphy.
Province/Territory: Nunavut

Originator: Sanford and Grant, 2000

Type Locality:
The type section is at Silliman's Fossil Mount near Iqaluit (63 deg 45'00" N 68 deg 56'45"W).

Distribution:
The Amadjuak Formation is exposed between the type section, Amadjuak Lake and the Putman Highland on southern Baffin Island, as well as on Akpatok Island and on Melville Peninsula between Igloolik Island and Roche Bay.

Lithology:
Three informal members are recognized at the type section, a lower shale and shaly limestone, a middle member of nodular limestone and shale, and an upper member of resistant weathering nodular limestone.

Fossils:
The fauna of Silliman's Fossil Mount and other areas of the Amadjuak Formation are described by Roy (1941), Miller et al. (1954), and Bolton (1977, 2000).

Relationship:
Unconformably overlies basement or the Frobisher Bay Formation. Conformably overlain by the Boas River Formation.

References:
Bolton, T.E. 1977. Ordovician megafauna, Melville Peninsula, southeastern District of Franklin; in, Geology of Ordovician rocks, Melville Peninsula and region, southeastern District of Franklin; McCracken, A.D. and Bolton, T.E. Geological Survey of Canada, Bulletin 269, pages 23-75.
Miller, A.K., Youngquist, W. and Collinson, C., 1954. Ordovician cephalopod fauna of Baffin Island. Geological Society of America, Memoir 62.
Roy, S.K., 1941. "The Upper Ordovician fauna of Frobisher Bay, Baffin Island"; Field Museum of Natural History, Geological Memoir, vol. 2, p. 20.
Sanford, B.V. and Grant, A.C., 2000. Geological framework of the Ordovician system in the southeast Arctic Platform, Nunavut; in, Geology and paleontology of the southeast Arctic Platform, and southern Baffin Island, Nunavut; McCracken, A.D. and Bolton, T.E. Geological Survey of Canada, Bulletin 557, 2000; pages 13-38.

Source: CSPG Lexicon of Canadian Stratigraphy, Volume 1, Arctic Archigelage (District of Franklin); R.L. Christie, A.F. Embry, G.A. Van Dyck (editor)
Contributor: K. Dewing; P.H. Davenport
Entry Reviewed: No
Name Set: Lithostratigraphic Lexicon
LastChange: 17 Feb 2009