Gun River Formation

Gun River Formation
Gun River Formation
Stratigraphic range: Early Silurian (Llandovery)
Type	Geological formation
Sub-units	Lachute Member; Innomée Member; Sandtop Member; Macgilvray Member;
Underlies	Menier Formation
Overlies	Merrimack Formation
Thickness	85 to 100 meters
Location
Region	Quebec
Country	Canada
Type section
Named by	Schuchert and Twenhofel
Year defined	1910

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.

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.
Anticostiodus	A. boltoni	Anticosti Island.
Icriodella	I. deflecta			Probably instead belongs to the Jupiter Formation.

Invertebrates

Brachiopods
Genus	Species	Presence	Material	Notes	Images
Brachyprion		Sandtop and Macgilvray Members.		A strophomenid.
Coolinia		Sandtop and Macgilvray Members.
Fenestrirostra	F. glacialis	Lowermost part of the formation.		A rhynchonellidalso found in the Merrimack Formation.
Fenestrirostra	F. pyrrha	Lachute Member.		A rhynchonellid.
'Gotatrypa'	'G.' sp.	Innommée Member.
Hyattidina		Sandtop to Macgilvray Members.		An athyrid.
Joviatrypa		Uppermost Macgilvray Member.
Kulumbella	K. xacta	Upper Macgilvray Member.		A pentamerid.
Mendacella		Innommée Member.		A dalmanellid.
Meristina		Innommée Member.
Pentamerus	P. palaformis	Top of the formation (uppermost Macgilvray Member).		Also found in the Jupiter Formation.
Stegerhynchus
Stricklandia	S. gwelani	Top of the formation (Macgilvray Member).		Also found in the Jupiter Formation.
Stricklandia	S. sp.	Innommée Member.	A509 (7 broken valves on a slab).	Also found in the uppermost Merrimack Formation.
Sypharatrypa	S. sp.	Innommée Member.

Bryozoans
Genus	Species	Presence	Material	Notes	Images
Phaenopora	P. superba			Also found in the Becscie Formation.
Ptilodictya	P. canadensis		USNM 143039.
Ptilodictya	P. sulcata		USNM 143039, 143050; YPM 3063/98, 3063/104.

Corals
Genus	Species	Presence	Material	Notes	Images
Acidolites	A. arctatus			A heliolitid.
Brachyelasma
Crassilasma
Helicelasma
Palaearaea		Cap aux Goélands (Uppermost Macgilvray Member).	Small colonies.	The only rugosan coral known from the formation, also found in the Menier formation.
Paleofavosites	P. capax		Multiple colonies.	A tabulate coral.

Crinoids
Genus	Species	Presence	Material	Notes	Images
Dendrocrinus
Eumyelodactylus		Macgilvray Member.
Laurocrinus		Macgilvray Member.
Stupatocrinus		Macgilvray Member.

Graptolites
Genus	Species	Presence	Material	Notes	Images
Paraclimacograptus	P. cf. innuitus	Deeper water facies of the Sandtop Member.

Sponges
Genus	Species	Presence	Material	Notes	Images
Camptodictyon				A stromatoporoid.
Clathrodictyon				A stromatoporoid.

References

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 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.
1 2 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.
1 2 3 4 5 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.
1 2 3 "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.

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[:2-1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 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.

[:1-2] 1 2 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.

[3] 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.

[:3-4] 1 2 3 4 5 Jin, Jisuo; Copper, Paul. "Late Ordovician and Early Silurian pentamerid brachiopods of Anticosti Island, Québec, Canada". Palaeontographica Canadiana.

[5] 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.

[:0-6] 1 2 3 "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.

[7] 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.

[8] 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.