ammonites
Lupine River (USGS Mes. loc. 22769) (Jurassic of the United States)

Where: Alaska (68.9° N, 148.4° W: paleocoordinates 74.8° N, 52.6° W)

• small collection-level geographic resolution

When: Tiglukpuk Formation, Kimmeridgian (155.7 - 150.8 Ma)

• ~300' above base of Kingak Shale.

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified, concretionary, sideritic, argillaceous, silty 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]

• shale as at usgs mes loc 22766: [fissile clay to silt shale containing spheroidal concretions and sideritic lenses.]

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 5223: authorized by John Alroy, entered by Mike Sommers on 02.09.1999

Creative Commons license: CC BY-NC-ND (attribution-noncommercial-no derivatives)