ammonites
USGS 16431-PC (Carboniferous of the United States)

Where: Jefferson County, Montana (45.9° N, 111.7° W: paleocoordinates 9.8° S, 45.6° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Lodgepole Limestone Formation, Kinderhookian (360.7 - 353.8 Ma)

• Age unsure: Author lists as "Early Mississippian," Lodgepole lies directly over the Three Forks Fm. which is Famennian. Going on assumption of Kinderkookian because of relation to the Three Forks/Sappington Fm.

• group of beds-level stratigraphic resolution

Environment/lithology: shallow subtidal; lithified, gray, green, yellow lime mudstone and limestone

• dark-gray microcrystalline limestone, beds 4 to 2' thick, that weathers yellowish gray to light olive gray. more coarsely crystalline beds increas upsection. partings of yellowish brown and grayish orange calcareous mudstone.

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

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 7313: authorized by John Alroy, entered by Mike Sommers on 23.05.2000

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