Twilight Section, Bathurst Island, Unit 18, Blue Fiord Formation: Emsian - Eifelian, Canada

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Trilobita - Proetida - Proetidae
Dechenella maclareni (Ormiston 1967)
see common names

Geography
Country:Canada State/province:Nunavut
Coordinates: 76.3° North, 99.3° West (view map)
Paleocoordinates:7.8° South, 19.7° West
Basis of coordinate:estimated from map
Geographic resolution:outcrop
Time
Period: Devonian Epoch: Early Devonian - Middle Devonian
Stage: Emsian - Eifelian 10 m.y. bin: Devonian 2 - Devonian 3
*International age/stage:Eifelian
Key time interval: Emsian - Eifelian
Age range of interval: 407.6 - 387.7 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Formation:Blue Fiord
Local section:Twilight Local bed:18
Local order:bottom to top
Stratigraphic resolution:group of beds
Stratigraphy comments: "Unit n" [from bottom] is my terminology, not Ormiston's. Unit is 20 feet thick.
Lithology and environment
Primary lithology:micaceous,red or brown "limestone"
Lithology description: 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: "limestone: lt. brown, finely crystalline, micaceous..."
Environment:shallow subtidal indet. Tectonic setting:passive margin
Geology comments: 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). "
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Reason for describing collection:biostratigraphic analysis
Metadata
Database number:26595
Authorizer:M. Foote Enterer:M. Foote
Modifier:P. Wagner Research group:marine invertebrate
Created:2002-10-18 08:27:36 Last modified:2021-11-14 00:26:46
Access level:the public Released:2002-10-18 08:27:36
Creative Commons license:CC BY
Reference information

Primary reference:
7308. 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]