Gun River Formation |
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Stratigraphic range: Early Silurian (Llandovery) |
Type | Geological formation |
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Sub-units | - Lachute Member
- Innomée Member
- Sandtop Member
- Macgilvray Member
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Underlies | Menier Formation[1] |
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Overlies | Merrimack Formation[1] |
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Thickness | 85 to 100 meters[1] |
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Location |
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Region | Quebec |
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Country | Canada |
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Type section |
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Named by | Schuchert and Twenhofel[1] |
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Year defined | 1910[1] |
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The Gun River Formation is a geologic formation in Quebec. It preserves fossils dating back to the early Silurian period.
Description
The formation is divided into 4 members (from the base up): the Lachute, Innommée, Sandtop and Macgilvray members. The formation was deposited some 40–80 km offshore from the stable Laurentian craton, underwater at depths of 30 to 60 meters.[1]
Fossil content
Vertebrates
| | |
Color key Taxon | Reclassified taxon | Taxon falsely reported as present | Dubious taxon or junior synonym | Ichnotaxon | Ootaxon | Morphotaxon | | | Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited. |
Conodonts |
Genus | Species | Presence | Material | Notes | Images |
Anticostiodus | A. fahraeusi | Anticosti Island.[2] | | | |
A. boltoni | Anticosti Island.[2] | | | |
Icriodella | I. deflecta | | | Probably instead belongs to the Jupiter Formation.[1] | |
Invertebrates
Brachiopods |
Genus | Species | Presence | Material | Notes | Images |
Brachyprion | | Sandtop and Macgilvray Members.[1] | | A strophomenid. | |
Coolinia | | Sandtop and Macgilvray Members.[1] | | | |
Fenestrirostra | F. glacialis | Lowermost part of the formation.[3] | | A rhynchonellidalso found in the Merrimack Formation. | |
F. pyrrha | Lachute Member.[1] | | A rhynchonellid. | |
'Gotatrypa' | 'G.' sp. | Innommée Member.[1] | | | |
Hyattidina | | Sandtop to Macgilvray Members.[1] | | An athyrid. | |
Joviatrypa | | Uppermost Macgilvray Member.[1] | | | |
Kulumbella | K. xacta | Upper Macgilvray Member.[4][5] | | A pentamerid. | |
Mendacella | | Innommée Member.[1] | | A dalmanellid. | |
Meristina | | Innommée Member.[1] | | | |
Pentamerus | P. palaformis | Top of the formation (uppermost Macgilvray Member).[1][4] | | Also found in the Jupiter Formation. | |
Stegerhynchus | | [1] | | | |
Stricklandia | S. gwelani | Top of the formation (Macgilvray Member).[1][4] | | Also found in the Jupiter Formation. | |
S. sp. | Innommée Member.[4] | A509 (7 broken valves on a slab).[4] | Also found in the uppermost Merrimack Formation. | |
Sypharatrypa | S. sp. | Innommée Member.[1] | | | |
Bryozoans |
Genus | Species | Presence | Material | Notes | Images |
Phaenopora | P. superba | | | Also found in the Becscie Formation.[6] | |
Ptilodictya | P. canadensis | | USNM 143039.[6] | | |
P. sulcata | | USNM 143039, 143050; YPM 3063/98, 3063/104.[6] | | |
Corals |
Genus | Species | Presence | Material | Notes | Images |
Acidolites | A. arctatus | [7] | | A heliolitid. | |
Brachyelasma | | [1] | | | |
Crassilasma | | [1] | | | |
Helicelasma | | [1] | | | |
Palaearaea | | Cap aux Goélands (Uppermost Macgilvray Member).[1] | Small colonies.[1] | The only rugosan coral known from the formation, also found in the Menier formation. | |
Paleofavosites | P. capax | | Multiple colonies.[8] | A tabulate coral. | |
Crinoids |
Genus | Species | Presence | Material | Notes | Images |
Dendrocrinus | | [1] | | | |
Eumyelodactylus | | Macgilvray Member.[1] | | | |
Laurocrinus | | Macgilvray Member.[1] | | | |
Stupatocrinus | | Macgilvray Member.[1] | | | |
Graptolites |
Genus | Species | Presence | Material | Notes | Images |
Paraclimacograptus | P. cf. innuitus | Deeper water facies of the Sandtop Member.[1] | | | |
See also
Earth sciences portal
Canada portal
Paleontology portal
References
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae Copper, Paul; Long, Darrel G. F.; Jin, Jisuo (2012). "The Early Silurian Gun River Formation of Anticosti Island, eastern Canada: A key section for the mid-Llandovery of North America". Newsletters on Stratigraphy. 45 (3): 263. doi:10.1127/0078-0421/2012/0024. ISSN 0078-0421.
- ^ a b Zhang, Shunxin; Barnes, Christopher R. (July 2000). "Anticostiodus, a new multielement conodont genus from the Lower Silurian, Anticosti Island, Quebec". Journal of Paleontology. 74 (4): 662–669. doi:10.1666/0022-3360(2000)074<0662:AANMCG>2.0.CO;2. ISSN 0022-3360. S2CID 59056082.
- ^ Jin, Jisuo; Caldwell, W. G. E.; Copper, Paul (March 1990). "Evolution of the Early Silurian rhynchonellid brachiopod Fenestrirostra in the Anticosti Basin of Quebec". Journal of Paleontology. 64 (2): 214–222. doi:10.1017/s0022336000018370. ISSN 0022-3360. S2CID 132248649.
- ^ a b c d e Jin, Jisuo; Copper, Paul. "Late Ordovician and Early Silurian pentamerid brachiopods of Anticosti Island, Québec, Canada". Palaeontographica Canadiana.
- ^ Jin, Jisuo; Copper, Paul (May 1998). "Kulumbella and Microcardinalia (Chiastodoca) new subgenus, Early Silurian divaricate stricklandiid brachiopods from Anticosti Island, eastern Canada". Journal of Paleontology. 72 (3): 441–453. doi:10.1017/s0022336000024185. ISSN 0022-3360. S2CID 132809506.
- ^ a b c "Larger Cryptostome Bryozoa of the Ordovician and Silurian, Anticosti Island, Canada". www.jstor.org. SEPM Society for Sedimentary Geology. JSTOR 1300852. Retrieved 2022-09-18.
- ^ Dixon, O. A. (January 1986). "The heliolitid coral Acidolites in Ordovician–Silurian rocks of eastern Canada1". Journal of Paleontology. 60 (1): 26–52. doi:10.1017/S002233600002148X. ISSN 0022-3360. S2CID 130759173.
- ^ Lee, Dong-Jin; Noble, James P. A. (July 1990). "Reproduction and life strategies in the Paleozoic tabulate coral Paleofavosites capax (Billings)". Lethaia. 23 (3): 257–272. doi:10.1111/j.1502-3931.1990.tb01452.x. ISSN 0024-1164.
- Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Archived from the original on 25 March 2022. Retrieved 17 December 2021.