Gun River Formation | |
---|---|
Stratigraphic range: Early Silurian ( Llandovery) | |
Type | Geological formation |
Sub-units |
|
Underlies | Menier Formation [1] |
Overlies | Merrimack Formation [1] |
Thickness | 85 to 100 meters [1] |
Location | |
Region | ![]() |
Country | ![]() |
Type section | |
Named by | Schuchert and Twenhofel [1] |
Year defined | 1910 [1] |
The Gun River Formation is a geologic formation in Quebec. It preserves fossils dating back to the early Silurian period.
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]
Color key
|
Notes Uncertain or tentative taxa are in small text; |
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] |
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] |
Sponges | |||||
---|---|---|---|---|---|
Genus | Species | Presence | Material | Notes | Images |
Camptodictyon | [1] | A stromatoporoid. | |||
Clathrodictyon | [1] | A stromatoporoid. |
Gun River Formation | |
---|---|
Stratigraphic range: Early Silurian ( Llandovery) | |
Type | Geological formation |
Sub-units |
|
Underlies | Menier Formation [1] |
Overlies | Merrimack Formation [1] |
Thickness | 85 to 100 meters [1] |
Location | |
Region | ![]() |
Country | ![]() |
Type section | |
Named by | Schuchert and Twenhofel [1] |
Year defined | 1910 [1] |
The Gun River Formation is a geologic formation in Quebec. It preserves fossils dating back to the early Silurian period.
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]
Color key
|
Notes Uncertain or tentative taxa are in small text; |
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] |
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] |
Sponges | |||||
---|---|---|---|---|---|
Genus | Species | Presence | Material | Notes | Images |
Camptodictyon | [1] | A stromatoporoid. | |||
Clathrodictyon | [1] | A stromatoporoid. |