Twilight Section, Bathurst Island, Unit 7, Blue Fiord Formation: Emsian, Canada
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Placodermi
- Antiarchiformes
- Asterolepididae
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Asterolepis sp.
Eichwald 1840
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Rhynchonellata
- Spiriferida
- Reticulariidae
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Warrenella sp.
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Trilobita
- Corynexochida
- Styginidae
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Ancyropyge arcticus
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Trilobita
- Proetida
- Proetidae
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Dechenella paragranulata
Ormiston 1967
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Dechenella maclareni
(Ormiston 1967)
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Trilobita
- Proetida
- Otarionidae
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Otarion balanops
Erben 1953
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see common names |
Geography
Country: | Canada | State/province: | Nunavut |
Coordinates: | 76.3° North, 99.3° West (view map) | ||
Paleocoordinates: | 8.4° South, 19.6° West | ||
Basis of coordinate: | estimated from map | ||
Geographic resolution: | outcrop |
Time
Period: | Devonian | Epoch: | Early Devonian |
Stage: | Emsian | 10 m.y. bin: | Devonian 2 |
*International age/stage: | Eifelian | ||
Key time interval: | Emsian | ||
Age range of interval: | 407.6 - 393.3 m.y. ago | ||
* legacy (obsolete) database fields |
Stratigraphy
Formation: | Blue Fiord | ||||
Local section: | Twilight | Local bed: | 7 | ||
Local order: | bottom to top | ||||
Stratigraphic resolution: | group of beds | ||||
Stratigraphy comments: "Unit n" [from bottom] is my terminology, not Ormiston's. Unit is 25 feet thick. |
Lithology and environment
Primary lithology: | gray,red or brown argillaceous "limestone" | ||
Secondary lithology: | red or brown argillaceous "limestone" | ||
Includes fossils? | Y | ||
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: "brownish grey, finely crystalline limestone grading upward into brown, argillacoues limestone which is crosed with trilobites..." | |||
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: | 26588 | ||
Authorizer: | M. Foote | Enterer: | M. Foote |
Modifier: | P. Wagner | Research group: | marine invertebrate |
Created: | 2002-10-18 08:12:56 | Last modified: | 2021-11-14 00:22:13 |
Access level: | the public | Released: | 2002-10-18 08:12:56 |
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] |