PBDB Collection

Section AV4B, Level 112 m, Whittaker Fm., Avalanche Lake Area, Mackenzie Mts. (Ordovician of Canada)

Where: Northwest Territories, Canada (62.4° N, 127.0° W: paleocoordinates 9.1° N, 55.4° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Normalograptus persculptus zone, Whittaker Formation, Hirnantian (445.2 - 443.4 Ma)

• group of beds-level stratigraphic resolution

Environment/lithology: open shallow subtidal; argillaceous limestone and calcareous shale

• For entire Whittaker/Road River/Delorme suite: "The sediments were deposited in an area adjacent to the boundary between the Paleozoic continental shelf (Mackenzie shelf/platform) and the slope into the marginal Selwyn Basin."

•SEP environmental call based primarily on PBDB ref. 7215. IF age assignment is correct, then this unit is consistent with the last portion of the HST in the upper-most Ord. and immediately prior to TST of lowermost-Sil. and latest Ord. Shallow assignment based on Bathyurus in ref. 7215.

• For entire Whittaker/Road River/Delorme suite: "The sediments are predominantly carbonates with varying amounts of argillaceous material, ranging from fairly pure limestones, through argillaceous limestones and calcareous shales, to almost pure siliciclastic shales with some intervals containing minor to major amounts of chert."

Preservation: replaced with silica

Primary reference: J. Jin and B. D. E. Chatterton. 1997. Latest Ordovician-Silurian articulate brachiopods and biostratigraphy of the Avalanche Lake area, southwestern District of Mackenzie, Canada. Palaeontographica Canadiana 13:1-62 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 26071: authorized by Michael Foote, entered by Michael Foote on 02.10.2002, edited by Melanie Hopkins and Pete Wagner

Creative Commons license: CC BY (attribution)

Taxonomic list

• Articulate brachiopods only.

Show authors, comments, and common names

Strophomenata
Strophomenida - Furcitellidae	Katastrophomena mackenzii² Katastrophomena mackenzii² Jin and Harper 2024
Rhynchonellata
Pentamerida - Virgianidae	Brevilamnulella laevis Brevilamnulella laevis Sapelnikov and Rukavishnikova 1975 2 sh, 18 vv, 4 dv
Orthida - Platystrophiidae	"Platystrophia orbiculoidea n. sp." = Gnamptorhynchos orbiculoidea "Platystrophia orbiculoidea n. sp." = Gnamptorhynchos orbiculoidea Jin and Chatterton 1997 5 sh, 27 vv/dv
Orthida - Dalmanellidae	Dalmanella edgewoodensis Dalmanella edgewoodensis Savage 1913 2 vv, 1 dv
Orthida - Dicoelosiidae	Epitomyonia sekwiensis Epitomyonia sekwiensis Lenz 1977 11 sh, 2 vv, 4 dv
Atrypida - Atrypinidae	Eospirigerina putilla Eospirigerina putilla Hall and Clarke 1894 33 sh, 9 vv, 9 dv
Trilobita
Lichida - Lichidae	Acanthopyge (Lobopyge) pristina n. sp.¹ Acanthopyge (Lobopyge) pristina n. sp.¹ Campbell and Chatterton 2006 trilobite sampled from 111.4 m

¹Campbell and Chatterton 2006; ²Jin and Harper 2024