Ivishak River (USGS Mes. loc. 22745) (Jurassic of the United States)

Where: Alaska (69.0° N, 148.1° W: paleocoordinates 71.8° N, 50.9° W)

• small collection-level geographic resolution

When: Kingak Shale Formation, Callovian (166.1 - 163.5 Ma)

• Within lower 400 ft of Kingak Shale.

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified, silty siltstone and shale

• "[These sediments] were deposited in an eastward-trending trough about 150 mi wide...the trough was bounded on the S by a rising landmass from which most of the sediments were derived. It was bounded on the N by the Barrow Platform..."

[ergo, foreland basin]

• siltstone lenses in hard, splintery, silty shale.

Reposited in the USGS

Primary reference: R. W. Imlay. 1955. Characteristic Jurassic Mollusks from northern Alaska. United States Geological Survey Professional Paper 274-D:69-96 [J. Alroy/M. Sommers]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 5226: authorized by John Alroy, entered by Mike Sommers on 02.09.1999

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Cephalopoda
 Ammonitida - Cardioceratidae
"Pseudocadoceras grewingki" = Cadoceras (Pseudocadoceras) grewingki
"Pseudocadoceras grewingki" = Cadoceras (Pseudocadoceras) grewingki Pompeckj 1900 ammonite