Gun River Formation

{{Infobox rockunit

| name = Gun River Formation

| image =

| caption =

| type = Geological formation

| age = Early Silurian (Llandovery)

| prilithology =

| otherlithology =

| namedfor =

| namedby = Schuchert and Twenhofel

| year_ts = 1910

| region = {{Flag|Quebec}}

| country = {{Flag|Canada}}

| coordinates =

| unitof =

| subunits = * Lachute Member

Innomée Member
Sandtop Member
Macgilvray Member

| underlies = Menier Formation

| overlies = Merrimack Formation

| thickness = 85 to 100 meters

| extent =

| area =

| map =

| map_caption =

}}

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.{{Cite journal |last1=Copper |first1=Paul |last2=Long |first2=Darrel G. F. |last3=Jin |first3=Jisuo |date=2012 |title=The Early Silurian Gun River Formation of Anticosti Island, eastern Canada: A key section for the mid-Llandovery of North America |url=https://www.academia.edu/20175056 |journal=Newsletters on Stratigraphy |volume=45 |issue=3 |pages=263 |doi=10.1127/0078-0421/2012/0024 |issn=0078-0421}}

Fossil content

=Vertebrates=

colspan="6" align="center" \| Conodonts
class="wikitable" align="center"
Genus	Species	Presence !Material	Notes	Images
rowspan=2\|Anticostiodus \|A. fahraeusi \| Anticosti Island.{{Cite journal \|last1=Zhang \|first1=Shunxin \|last2=Barnes \|first2=Christopher R. \|date=July 2000 \|title=Anticostiodus, a new multielement conodont genus from the Lower Silurian, Anticosti Island, Quebec \|url=https://www.cambridge.org/core/journals/journal-of-paleontology/article/abs/anticostiodus-a-new-multielement-conodont-genus-from-the-lower-silurian-anticosti-island-quebec/519482BD2AB9F372331DE53A21B76716 \|journal=Journal of Paleontology \|language=en \|volume=74 \|issue=4 \|pages=662–669 \|doi=10.1666/0022-3360(2000)074<0662:AANMCG>2.0.CO;2 \|s2cid=59056082 \|issn=0022-3360\|url-access=subscription }} \| \| \|
A. boltoni \|Anticosti Island. \| \| \|
style="background:#f3e9f3;" \|Icriodella \|style="background:#f3e9f3;" \|I. deflecta \|style="background:#f3e9f3;" \| \|style="background:#f3e9f3;" \| \|style="background:#f3e9f3;" \|Probably instead belongs to the Jupiter Formation. \|style="background:#f3e9f3;" \|

=Invertebrates=

class="wikitable" align="center"
colspan="6" align="center" \| Brachiopods
Genus	Species	Presence !Material	Notes	Images
Brachyprion \| \|Sandtop and Macgilvray Members. \| \|A strophomenid. \|
Coolinia \| \|Sandtop and Macgilvray Members. \| \| \|
rowspan="2" \|Fenestrirostra \|F. glacialis \|Lowermost part of the formation.{{Cite journal \|last1=Jin \|first1=Jisuo \|last2=Caldwell \|first2=W. G. E. \|last3=Copper \|first3=Paul \|date=March 1990 \|title=Evolution of the Early Silurian rhynchonellid brachiopod Fenestrirostra in the Anticosti Basin of Quebec \|url=https://www.researchgate.net/publication/266477153 \|journal=Journal of Paleontology \|volume=64 \|issue=2 \|pages=214–222 \|doi=10.1017/s0022336000018370 \|s2cid=132248649 \|issn=0022-3360}} \| \|A rhynchonellidalso found in the Merrimack Formation. \|
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.{{Cite journal \|last1=Jin \|first1=Jisuo \|last2=Copper \|first2=Paul \|date=May 1998 \|title=Kulumbella and Microcardinalia (Chiastodoca) new subgenus, Early Silurian divaricate stricklandiid brachiopods from Anticosti Island, eastern Canada \|url=https://www.researchgate.net/publication/266477122 \|journal=Journal of Paleontology \|volume=72 \|issue=3 \|pages=441–453 \|doi=10.1017/s0022336000024185 \|s2cid=132809506 \|issn=0022-3360}} \| \|A pentamerid. \|
Mendacella \| \|Innommée Member. \| \|A dalmanellid. \|
Meristina \| \|Innommée Member. \| \| \|
Pentamerus \|P. palaformis \|Top of the formation (uppermost Macgilvray Member).{{Cite journal \|last1=Jin \|first1=Jisuo \|last2=Copper \|first2=Paul \|title=Late Ordovician and Early Silurian pentamerid brachiopods of Anticosti Island, Québec, Canada \|url=https://www.academia.edu/20175090 \|journal=Palaeontographica Canadiana}} \| \|Also found in the Jupiter Formation. \|
Stegerhynchus \| \| \| \| \|
rowspan=2\|Stricklandia \|S. gwelani \|Top of the formation (Macgilvray Member). \| \|Also found in the Jupiter Formation. \|
S. sp. \|Innommée Member. \|A509 (7 broken valves on a slab). \|Also found in the uppermost Merrimack Formation. \|
Sypharatrypa \|S. sp. \|Innommée Member. \| \| \|

class="wikitable" align="center"

colspan="6" align="center" | Brachiopods

Genus

Species

Presence

!Material

Notes

Images

Brachyprion

|Sandtop and Macgilvray Members.

|A strophomenid.

Coolinia

|Sandtop and Macgilvray Members.

rowspan="2" |Fenestrirostra

|F. glacialis

|Lowermost part of the formation.{{Cite journal |last1=Jin |first1=Jisuo |last2=Caldwell |first2=W. G. E. |last3=Copper |first3=Paul |date=March 1990 |title=Evolution of the Early Silurian rhynchonellid brachiopod Fenestrirostra in the Anticosti Basin of Quebec |url=https://www.researchgate.net/publication/266477153 |journal=Journal of Paleontology |volume=64 |issue=2 |pages=214–222 |doi=10.1017/s0022336000018370 |s2cid=132248649 |issn=0022-3360}}

|A rhynchonellidalso found in the Merrimack Formation.

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.{{Cite journal |last1=Jin |first1=Jisuo |last2=Copper |first2=Paul |date=May 1998 |title=Kulumbella and Microcardinalia (Chiastodoca) new subgenus, Early Silurian divaricate stricklandiid brachiopods from Anticosti Island, eastern Canada |url=https://www.researchgate.net/publication/266477122 |journal=Journal of Paleontology |volume=72 |issue=3 |pages=441–453 |doi=10.1017/s0022336000024185 |s2cid=132809506 |issn=0022-3360}}

|A pentamerid.

Mendacella

|Innommée Member.

|A dalmanellid.

Meristina

|Innommée Member.

Pentamerus

|P. palaformis

|Top of the formation (uppermost Macgilvray Member).{{Cite journal |last1=Jin |first1=Jisuo |last2=Copper |first2=Paul |title=Late Ordovician and Early Silurian pentamerid brachiopods of Anticosti Island, Québec, Canada |url=https://www.academia.edu/20175090 |journal=Palaeontographica Canadiana}}

|Also found in the Jupiter Formation.

Stegerhynchus

rowspan=2|Stricklandia

|S. gwelani

|Top of the formation (Macgilvray Member).

|Also found in the Jupiter Formation.

S. sp.

|Innommée Member.

|A509 (7 broken valves on a slab).

|Also found in the uppermost Merrimack Formation.

Sypharatrypa

|S. sp.

|Innommée Member.

colspan="6" align="center" \| Bryozoans
class="wikitable" align="center"
Genus	Species	Presence !Material	Notes	Images
Phaenopora \|P. superba \| \| \|Also found in the Becscie Formation.{{Cite journal \|title=Larger Cryptostome Bryozoa of the Ordovician and Silurian, Anticosti Island, Canada \|publisher=SEPM Society for Sedimentary Geology \|url=https://www.jstor.org/stable/1300852 \|access-date=2022-09-18 \|website=www.jstor.org \|jstor=1300852 \|language=en}} \|
rowspan="2" \|Ptilodictya \|P. canadensis \| \|USNM 143039. \| \|
P. sulcata \| \|USNM 143039, 143050; YPM 3063/98, 3063/104. \| \|

class="wikitable" align="center"
colspan="6" align="center" \| Corals
Genus	Species	Presence !Material	Notes	Images
Acidolites \|A. arctatus \|{{Cite journal \|last=Dixon \|first=O. A. \|date=January 1986 \|title=The heliolitid coral Acidolites in Ordovician–Silurian rocks of eastern Canada1 \|url=https://www.cambridge.org/core/journals/journal-of-paleontology/article/abs/heliolitid-coral-acidolites-in-ordoviciansilurian-rocks-of-eastern-canada-1/C856A953F9E0E1A1C24D610DAA839C15 \|journal=Journal of Paleontology \|language=en \|volume=60 \|issue=1 \|pages=26–52 \|doi=10.1017/S002233600002148X \|s2cid=130759173 \|issn=0022-3360\|url-access=subscription }} \| \|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.{{Cite journal \|last1=Lee \|first1=Dong-Jin \|last2=Noble \|first2=James P. A. \|date=July 1990 \|title=Reproduction and life strategies in the Paleozoic tabulate coral Paleofavosites capax (Billings) \|url=https://onlinelibrary.wiley.com/doi/10.1111/j.1502-3931.1990.tb01452.x \|journal=Lethaia \|language=en \|volume=23 \|issue=3 \|pages=257–272 \|doi=10.1111/j.1502-3931.1990.tb01452.x \|issn=0024-1164\|url-access=subscription }} \|A tabulate coral. \|

class="wikitable" align="center"

colspan="6" align="center" | Corals

Genus

Species

Presence

!Material

Notes

Images

Acidolites

|A. arctatus

|{{Cite journal |last=Dixon |first=O. A. |date=January 1986 |title=The heliolitid coral Acidolites in Ordovician–Silurian rocks of eastern Canada1 |url=https://www.cambridge.org/core/journals/journal-of-paleontology/article/abs/heliolitid-coral-acidolites-in-ordoviciansilurian-rocks-of-eastern-canada-1/C856A953F9E0E1A1C24D610DAA839C15 |journal=Journal of Paleontology |language=en |volume=60 |issue=1 |pages=26–52 |doi=10.1017/S002233600002148X |s2cid=130759173 |issn=0022-3360|url-access=subscription }}

|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.{{Cite journal |last1=Lee |first1=Dong-Jin |last2=Noble |first2=James P. A. |date=July 1990 |title=Reproduction and life strategies in the Paleozoic tabulate coral Paleofavosites capax (Billings) |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1502-3931.1990.tb01452.x |journal=Lethaia |language=en |volume=23 |issue=3 |pages=257–272 |doi=10.1111/j.1502-3931.1990.tb01452.x |issn=0024-1164|url-access=subscription }}

|A tabulate coral.

colspan="6" align="center" \| Crinoids
class="wikitable" align="center"
Genus	Species	Presence !Material	Notes	Images
Dendrocrinus \| \| \| \| \|
Eumyelodactylus \| \|Macgilvray Member. \| \| \|
Laurocrinus \| \|Macgilvray Member. \| \| \|
Stupatocrinus \| \|Macgilvray Member. \| \| \|

class="wikitable" align="center"
colspan="6" align="center" \| Graptolites
Genus	Species	Presence !Material	Notes	Images
Paraclimacograptus \|P. cf. innuitus \| Deeper water facies of the Sandtop Member. \| \| \|

class="wikitable" align="center"

colspan="6" align="center" | Graptolites

Genus

Species

Presence

!Material

Notes

Images

Paraclimacograptus

|P. cf. innuitus

| Deeper water facies of the Sandtop Member.

colspan="6" align="center" \| Sponges
class="wikitable" align="center"
Genus	Species	Presence !Material	Notes	Images
Camptodictyon \| \| \| \|A stromatoporoid. \|
Clathrodictyon \| \| \| \| A stromatoporoid. \|

References

{{cite web|title= Fossilworks: Gateway to the Paleobiology Database|author= ((Various Contributors to the Paleobiology Database))|url= https://www.fossilworks.org|access-date= 17 December 2021|archive-date= 25 March 2022|archive-url= https://web.archive.org/web/20220325060448/http://www.fossilworks.org/cgi-bin/bridge.pl?action=home|url-status= live}}

Category:Silurian Quebec

Category:Silurian southern paleotemperate deposits

Category:Silurian southern paleotropical deposits

Category:Geologic formations of Quebec

Gun River Formation

Description

Fossil content

=Vertebrates=

=Invertebrates=

See also

References