GSC 53050. Blackstone River Section (Ordovician of Canada)

Also known as District of Mackenzie, Blackstone River Section, Unit 2 Road River Formation

Where: Northwest Territories, Canada (65.4° N, 137.4° W: paleocoordinates 9.5° N, 57.6° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Lower Road River Formation, Arenigian (478.6 - 468.1 Ma)

• Collection taken from 148-162 and 254-260 feet above the base.

• group of beds-level stratigraphic resolution

Environment/lithology: deep subtidal; black shale and black, gray, argillaceous limestone

• "Limy shale, greyish black, weathers greyish black, dark brownish grey, recessive, fissility poor to good; minor argillaceous limestone, very finely crystalline, dark grey, greyish black, weathers grey, greyish black, yellowish grey, bedding 1 inch to 6 inches, some beds finely laminated."

Size class: macrofossils

Collection methods: Collection includes trilobites, diplograptid graptolites, and inarticulate brachiopods.

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 25517: authorized by Steven Holland, entered by Tori Hanson on 14.09.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

 Graptoloidea - Phyllograptidae
 Graptoloidea - Dichograptidae
Didymograptus cf. extensus Hall 1858 graptolite
 Graptoloidea - Isograptidae
? Isograptus sp. Moberg 1892 graptolite