Twilight Section, Bathurst Island, Unit 4, Blue Fiord Formation (Devonian of Canada)

Where: Nunavut, Canada (76.3° N, 99.3° W: paleocoordinates 8.4° S, 19.6° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Blue Fiord Formation, Emsian (407.6 - 393.3 Ma)

• "Unit n" [from bottom] is my terminology, not Ormiston's. Unit is 35 feet thick.

• group of beds-level stratigraphic resolution

Environment/lithology: shallow subtidal; argillaceous limestone and limestone

• Some bioherms observed in section.

•SEP: From Rose (1999) Sedimentology and diagenesis of the lower Blue Fiord Formation carbonates in a prospective mississippi valley-type (Pb-Zn) setting, Bathurst Island, N.W.T. Univ. of Calgary MS thesis: "The Devonian Blue Fiord Formation (Emsian-Eifelian) consists of subtidal to supratidal carbonates deposited on a wide platform shelf. It is divided into three informal members based on facies associations; BF (sub 1) (Subtidal Restricted), BF (sub 2) (Lagoonal-Tidal Flat), and BF (sub 3) (Subtidal Open/Restricted). "

• Section: "On northern Bathurst Island, the B.F. Fm. consists of light to dark brown, finely crystalline, medium-bedded, fossiliferous limestone interbedded with brown, medium to coarsly crystalline, bioclastic limestone and grey calcareous shale." This unit: "brown, finely crystallin, thin-bedded, argillaceous [limestone]...with a minor amount of pale brown limestone"

Size class: macrofossils

Primary reference: A. R. Ormiston. 1967. Lower and Middle Devonian trilobites of the Canadian arctic islands. Geological Survey of Canada Bulletin 153:1-148 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 26585: authorized by Michael Foote, entered by Michael Foote on 18.10.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Inarticulata
  -
"Inarticulata" indet.
Strophomenata
 Productida - Productellidae
Productella sp.
 Strophomenida - Douvillinidae
? Douvillina sp.
Trilobita
 Proetida - Proetidae
"Dechenella paragranulata" = Aayemenaytcheia paragranulata, ? Deltadechenella sp.
"Dechenella paragranulata" = Aayemenaytcheia paragranulata Ormiston 1967 trilobite
? Deltadechenella sp. Ormiston 1967 trilobite