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Table 1. New and revised Cretaceous and Tertiary stratigraphic nomenclature, Colville basin, northern Alaska
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Unit Age Unit Age Comments

Units of Tertiary Age

Sagavanirktok Formation (revised) Paleocene to Pliocene(?). Sagavanirktok Formation Paleocene to Pliocene(?). --
  Nuwok Member (unchanged) Miocene(?) to Pliocene(?).   Nuwok Member Miocene(?) to Pliocene(?). The Nuwok Member is exposed in the eastern Colville basin and was not considered in this study. The member was defined by Detterman and others (1975).
  Franklin Bluffs Member (revised) early Eocene to Miocene.   Franklin Bluffs Member Oligocene(?) to Miocene(?). The lower boundary of the Franklin Bluffs Member is revised.
  White Hills Member (new) late Paleocene(?) to early Eocene.   -- -- The White Hills Member includes some rocks formerly in the Franklin Bluffs and Sagwon Members.
  Sagwon Member (revised) late Paleocene   Sagwon Member Paleocene to Eocene(?). The upper and lower boundaries of the Sagwon Member are revised.

Units of Cretaceous to Tertiary age

Colville Group (abandoned) -- Colville Group Late Cretaceous Names are retained for units formerly in the Colville Group: Prince Creek Formation, Schrader Bluff Formation, Tuluvak Formation, and Seabee Formation.
Prince Creek Formation (revised) Campanian to Paleocene. Prince Creek Formation Late Cretaceous The revised Prince Creek Formation consists only of the rocks formerly mapped as the Kogosukruk Tongue. The Tuluvak Tongue is raised to formation rank.
  Kogosukruk Tongue (abandoned) -- Kogosukruk Tongue of the Prince Creek Formation. Late Cretaceous The Kogosukruk Tongue is abandoned. Its rocks are assigned to the Prince Creek Formation.

Units of Cretaceous age

Schrader Bluff Formation (revised) Santonian to Maastrichtian. Schrader Bluff Formation, consisting of, in descending order, Sentinel Hill Member, Barrow Trail Member, and Rogers Creek Member. Late Cretaceous The three named members of the Schrader Bluff Formation are abandoned; where appropriate, the informal terms upper, middle, and lower parts of the Schrader Bluff Formation are recommended.
  Sentinel Hill Member (abandoned) -- Sentinel Hill Member Late Cretaceous The Sentinel Hill Member is abandoned.
  Barrow Trail Member (abandoned) -- Barrow Trail Member Late Cretaceous The Barrow Trail Member is abandoned.
  Rogers Creek Member (abandoned) -- Rogers Creek Member Late Cretaceous The Rogers Creek Member is abandoned.
Tuluvak Formation (revised) Turonian to Coniacian. Tuluvak Tongue of the Prince Creek Formation and Ayiyak Member of the Seabee Formation. Late Cretaceous The Tuluvak Tongue is raised in rank to the Tuluvak Formation. The revised Tuluvak Formation includes rocks formerly mapped as the Tuluvak Tongue of the Prince Creek Formation and the Ayiyak Member of the Seabee Formation. The Ayiyak Member is abandoned.
Seabee Formation (revised) Cenomanian to Coniacian, mostly Turonian. Shale Wall Member of the Seabee Formation. Late Cretaceous The revised Seabee Formation includes only rocks formerly mapped as the Shale Wall Member of the Seabee Formation. The Shale Wall Member is abandoned.
Ayiyak Member (abandoned) -- Ayiyak Member of the Seabee Formation. Late Cretaceous The Ayiyak Member is abandoned. Its rocks are assigned to the Tuluvak Formation.
Shale Wall Member (abandoned) -- Shale Wall Member of the Seabee Formation. Late Cretaceous The Shale Wall Member is abandoned. Its rocks are assigned to the Seabee Formation.
Nanushuk Formation (revised) Albian to Cenomanian. Nanushuk Group. On the east-central Arctic Slope, the former Nanushuk Group consisted of, in descending order, Ninuluk Formation (marine), Niakogon and Killik Tongues of Chandler Formation (nonmarine), Grandstand Formation (transitional marine and nonmarine), and Tuktu Formation (marine). On the western Arctic Slope, the former Nanushuk Group consisted of, in descending order, the Corwin Formation (nonmarine) and the Kukpowruk Formation (marine). Early and Late Cretaceous. The Nanushuk Group is reduced in rank to the Nanushuk Formation. The unit names (middle column) in the Nanushuk Group are abandoned. In areas in which the formation can be divided into dominantly nonmarine and dominantly marine units, the informal terms upper and lower parts of the Nanushuk Formation, respectively, are recommended.
Ninuluk Formation (abandoned) -- Ninuluk Formation Early and Late Cretaceous. The Ninuluk Formation is abandoned.
Chandler Formation (abandoned) -- Chandler Formation Early and Late Cretaceous. The Chandler Formation is abandoned.
Niakogon Tongue (abandoned) -- Niakogon Tongue Early and Late Cretaceous. The Niakogon Tongue is abandoned.
Killik Tongue (abandoned) -- Killik Tongue Early and Late Cretaceous. The Killik Tongue is abandoned.
Corwin Formation (abandoned) -- Corwin Formation Early and Late Cretaceous The Corwin Formation is abandoned.
Grandstand Formation (abandoned) -- Grandstand Formation Early Cretaceous The Grandstand Formation is abandoned.
Tuktu Formation (abandoned) -- Tuktu Formation Early Cretaceous The Tuktu Formation is abandoned.
Kukpowruk Formation (abandoned) -- Kukpowruk Formation Early Cretaceous The Kukpowruk Formation is abandoned.
Torok Formation (unchanged) Aptian to Cenomanian. Torok Formation Early Cretaceous The formation definition is unchanged.

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