ammonites
Hossfeldt Hills locality no. 425 (Devonian of the United States)

Also known as USGS 16472-PC

Where: Broadwater County, Montana (46.0° N, 111.5° W: paleocoordinates 15.0° S, 46.3° W)

• coordinate based on political unit

• small collection-level geographic resolution

When: Three Forks Shale Formation, Famennian (376.1 - 360.7 Ma)

• 25-30 feet below Lodgepole Limestone, 30-35 feet above base of upper siltstone unit. Authors initially listed this outcrop as Mississippian in age. However, later workers have shown that the Three Forks Shale is all Devonian in age.

• group of beds-level stratigraphic resolution

Environment/lithology: offshore; lithified, yellow siltstone

• orange or yellow siltstone

Reposited in the USGS

Primary reference: G. D. Robinson. 1963. Geology of the Three Forks Quadrangle, Montana. United States Geological Survey Professional Paper 370:1-143 [J. Alroy/M. Sommers] more details

PaleoDB collection 7218: authorized by John Alroy, entered by Mike Sommers on 19.05.2000

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