District of Mackenzie, Sunblood Mountain Isotelus Biofacies (A-190): Blackriveran, Canada
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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Strophomenata
- Strophomenida
- Strophomenidae
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Strophomena sp.
Rafinesque and De Blainville 1824
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Trilobita
- Corynexochida
- Illaenidae
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Nanillaenus sp.
Jaanusson 1954
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Bumastoides sp.
(Whittington 1954)
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Trilobita
- Asaphida
- Asaphidae
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Nahannia sp.
Chatterton and Ludvigsen 1976
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Isotelus sp.
Dekay 1824
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| see common names | |||||||
Geography
| Country: | Canada | State/province: | Northwest Territories | County: | District of Mackenzie |
| Coordinates: | 61.6° North, 125.8° West (view map) | ||||
| Paleocoordinates: | 6.8° North, 58.0° West | ||||
| Basis of coordinate: | estimated from map | ||||
| Geographic resolution: | outcrop |
Time
| Period: | Ordovician | Epoch: | Late/Upper Ordovician |
| 10 m.y. bin: | Ordovician 4-5 | ||
| *Period: | Middle Ordovician | *Local age/stage: | Blackriveran |
| Key time interval: | Blackriveran | ||
| Age range of interval: | 457.00000 - 449.80000 m.y. ago | ||
| * legacy (obsolete) database fields | |||
Stratigraphy
| Formation: | Esbataottine | ||
| Local section: | Section A | Local bed: | 190 ft |
| Local order: | bottom to top | ||
| Stratigraphic resolution: | formation |
Lithology and environment
| Primary lithology: | argillaceous,silty "limestone" |
| Includes fossils? | Y |
| Lithology description: "[H]omogeneous sequence of micrites and microbiosparites, commonly silty and argillaceous. The bedding is regular to nodular and generally thin (3-8 cm) to medium (8-20 cm), rarely thickly bedded. Sand-size components are absent and more common biotic contributors to skeletal sands (pelmatozoans, heavy-shelled brachiopods, algae, corals, or stromatoporioids) are rare or absent." | |
| Environment: | deep subtidal indet. |
| Geology comments: "[H]omogeneous, probably soft bottom, carbonate and mud substrate, deposited under quiet water conditions on a wide shelf ranging from the littoral to, possibly, deep sub-littoral zones." | |
Taphonomy
| Modes of preservation: | replaced with silica |
| Size of fossils: | macrofossils,microfossils |
Collection methods and comments
| Collection excludes: | all microfossils,some macrofossils,species names |
| Collection methods: | field collection |
| Reason for describing collection: | biostratigraphic analysis |
| Collection method comments: Also includes leperditellid and oepikellid ostracods and bryozoans. | |
Metadata
| Also known as: | A 190 | ||
| Database number: | 25930 | ||
| Authorizer: | S. Holland | Enterer: | T. Hanson |
| Modifier: | M. Hopkins | Research group: | marine invertebrate |
| Created: | 2002-09-28 18:31:54 | Last modified: | 2011-01-12 14:48:52 |
| Access level: | the public | Released: | 2002-09-28 18:31:54 |
| Creative Commons license: | CC BY | ||
Reference information
Primary reference:
| 7069. | B. D. E. Chatterton and R. Ludvigsen. 1976. Silicified Middle Ordovician trilobites from the South Nahanni River Area, District of Mackenzie, Canada. Palaeontographica Abteilung A 154(1-3):1-106 [S. Holland/T. Hanson/T. Hanson] |