District of Mackenzie, Trail River Section Unit 3, Road River Fm (Dresbachian) (Cambrian of Canada)

Where: Northwest Territories, Canada (66.4° N, 135.5° W: paleocoordinates 5.3° N, 60.0° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Road River Formation, Dresbachian (497.0 - 485.4 Ma)

• Collection taken from 803-805 feet above base. Upper Cambrian, probably Dresbach.

• formation-level stratigraphic resolution

Environment/lithology: deep subtidal; gray limestone and gray shale

• "Limestone, very finely crystalline, grey, dark grey, bluish grey, weathers greyish yellow, grey, bluish grey, light grey, bedding 1/2 inch to 4 inches, some beds platy, some beds banded on weathered surfaces; very rare bioclastic layers; very rare black chert nodules; very rare shale, limy, dark grey, dark brownish grey, weathers dark grey, dark brownish grey, yellowish grey, fissility poor to good."

Size class: macrofossils

Collection methods: Collection also includes an inarticulate brachiopod and a trilobite.

Primary reference: B. S. Norford. 1963. Reconnaissance of the Ordovician and Silurian rocks of Northern Yukon Territory. Geological Survey of Canada Department of Mines and Technical Surveys, Paper 63(39):1-139 [S. Holland/T. Hanson/P. Wagner]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 25607: authorized by Steven Holland, entered by Tori Hanson on 18.09.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

 Ptychopariida - Tricrepicephalidae
cf. Tricrepicephalus sp. Kobayashi 1935 trilobite