Becscie Formation

{{Infobox rockunit

| name = Becscie Formation

| image =

| caption =

| type = Geological formation

| age = {{fossil range|Llandovery|Llandovery|Early Silurian}}

| prilithology =

| otherlithology =

| namedfor =

| namedby =

| region = {{Flag|Quebec}}

| country = {{flag|Canada}}

| coordinates =

| unitof =

| subunits = * Fox Point Member (lower)

Chabot Member (upper)

| underlies = Gun River Formation

| overlies = Ellis Bay Formation

| thickness = 80 to 85 meters

| extent =

| area =

| map =

| map_caption =

}}

The Becscie Formation is a geologic formation in Quebec. It preserves fossils dating back to the early Silurian period.

Description

The Becscie Formation is 80 to 85 meters thick. It overlies the Ordovician-Silurian boundary on Anticosti Island, marking a major oceanic and climatic changeover from the glacial sea-level lowstand and interglacial highstand cycles of the underlying Ellis Bay Formation to the more stable warming climate of the earliest Silurian, and extends approximately parallel to an ancient coastline some 200 km east to west.{{Cite journal |last1=Copper |first1=Paul |last2=Jin |first2=Jisuo |date=2014-04-01 |title=The revised Lower Silurian (Rhuddanian) Becscie Formation, Anticosti Island, eastern Canada records the tropical marine faunal recovery from the end-Ordovician Mass Extinction |url=https://www.researchgate.net/publication/262580310 |journal=Newsletters on Stratigraphy |volume=47 |issue=1 |pages=61–83 |doi=10.1127/0078-0421/2014/0040 |issn=0078-0421}} The formation is divided into two members, a lower Fox Point Member (spanning the Viridita lenticularis Biozone), and an upper Chabot Member (spanning the Virgiana barrandei Biozone).

Fossil content

colspan="6" align="center" \| Arthropods
class="wikitable" align="center"
Genus	Species	Presence !Material	Notes	Images
Anticostibolbina \| \|Chabot Member. \| \|A beyrichiacean ostracod. \|
Bolbineossia \| \|Chabot Member. \| \|A beyrichiacean ostracod. \|
Conbathella \| \|Chabot Member. \| \|A beyrichiacean ostracod. \|
Herrmannina \|H. selwyni \| Lower Becscie Formation. \| \| An ostracod \|
Zygobursa \| \|Chabot Member. \| \|A beyrichiacean ostracod. \|

class="wikitable" align="center"
colspan="6" align="center" \| Brachiopods
Genus	Species	Presence !Material	Notes	Images
Becscia \|B. scissura \| \|"Occurs commonly in lenses and clusters". \|An atrypid. \|
Biparetis \| \| \| \|Elsewhere known from the early Silurian, but locally rare. \|
Brachyprion \| \|Occurs sparsely in the Chabot Member. \| \| \|
Eospirigerina \|E. sp. \|Fox Point Member. \| \|An unnamed species, represents earliest known Silurian species of this Ordovician genus. \|
Hesperorthis \| \|Fox Point Member. \| \|An orthide. \|
Isorthis (Ovalella) \| \|Fox Point Member. \| \|An orthide. \|
Koigia \| \| \| \|An athyridid, originally reported as Hindella. \|
Leptaena \| \|Fox Point Member bedding plane. \| \| \|
Mendacella \|M. udauberis \|Fox Point Member, rare in the Chabot Member. \| \|An orthide. \|
Saukrodictya \| \|Fox Point Member. \| \|An orthide. \|
Virgiana \|V. barrandei \|Only in the Chabot 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}} \| \|A large-shelled pentameride. \|
rowspan=2\|Viridita \|V. becsciensis \|Fox Point Member. \|"Holotype, YPM 10341, and paratype, YPM 35519". \| \|
V. lenticularis \| Near the top of the Fox Point Member, and the Chabot Member. \| \| \|
Zygospiraella \|Z. cf. Z. planoconvexa \|Lower Becscie Formation, rare taxon in the lower Chabot Member. \| \| \|

class="wikitable" align="center"

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

Genus

Species

Presence

!Material

Notes

Images

Becscia

|B. scissura

|"Occurs commonly in lenses and clusters".

|An atrypid.

Biparetis

|Elsewhere known from the early Silurian, but locally rare.

Brachyprion

|Occurs sparsely in the Chabot Member.

Eospirigerina

|E. sp.

|Fox Point Member.

|An unnamed species, represents earliest known Silurian species of this Ordovician genus.

Hesperorthis

|Fox Point Member.

|An orthide.

Isorthis (Ovalella)

|Fox Point Member.

|An orthide.

Koigia

|An athyridid, originally reported as Hindella.

Leptaena

|Fox Point Member bedding plane.

Mendacella

|M. udauberis

|Fox Point Member, rare in the Chabot Member.

|An orthide.

Saukrodictya

|Fox Point Member.

|An orthide.

Virgiana

|V. barrandei

|Only in the Chabot 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}}

|A large-shelled pentameride.

rowspan=2|Viridita

|V. becsciensis

|Fox Point Member.

|"Holotype, YPM 10341, and paratype, YPM 35519".

V. lenticularis

| Near the top of the Fox Point Member, and the Chabot Member.

Zygospiraella

|Z. cf. Z. planoconvexa

|Lower Becscie Formation, rare taxon in the lower Chabot Member.

class="wikitable" align="center"
colspan="6" align="center" \| Bryozoans
Genus	Species	Presence !Material	Notes	Images
Phaenopora \|P. superba \| Fox Point and Chabot Members. \| \| "Extends into the overlying Gun River Formation"{{Cite journal \|last=Ross \|first=June Phillips \|date=1960 \|title=Larger Cryptostome Bryozoa of the Ordovician and Silurian, Anticosti Island, Canada: Part I \|url=https://www.jstor.org/stable/1300852 \|journal=Journal of Paleontology \|volume=34 \|issue=6 \|pages=1057–1076 \|jstor=1300852 \|issn=0022-3360}} \|

class="wikitable" align="center"

colspan="6" align="center" | Bryozoans

Genus

Species

Presence

!Material

Notes

Images

Phaenopora

|P. superba

| Fox Point and Chabot Members.

| "Extends into the overlying Gun River Formation"{{Cite journal |last=Ross |first=June Phillips |date=1960 |title=Larger Cryptostome Bryozoa of the Ordovician and Silurian, Anticosti Island, Canada: Part I |url=https://www.jstor.org/stable/1300852 |journal=Journal of Paleontology |volume=34 |issue=6 |pages=1057–1076 |jstor=1300852 |issn=0022-3360}}

class="wikitable" align="center"
colspan="6" align="center" \| Corals
Genus	Species	Presence !Material	Notes	Images
rowspan=3\|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. \|
A. compactus \| \| \|A heliolitid. \|
A. lindströmi \| \| \|A heliolitid. \|
Nanonphyllum \|N. pelagicum \|Common in the Chabot Member. \| \|A colonial rugose coral. \|
Paleofavosites \| \|More common towards the upper part of the Fox Point Member. \| \|A heliolitid tabulate coral. \|
Palaeophyllum \| \|Common in the Chabot Member. \| \| \|
Propora \| \| More common towards the upper part of the Fox Point Member. \| \| A heliolitid tabulate coral. \|

class="wikitable" align="center"

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

Genus

Species

Presence

!Material

Notes

Images

rowspan=3|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.

A. compactus

|A heliolitid.

A. lindströmi

|A heliolitid.

Nanonphyllum

|N. pelagicum

|Common in the Chabot Member.

|A colonial rugose coral.

Paleofavosites

|More common towards the upper part of the Fox Point Member.

|A heliolitid tabulate coral.

Palaeophyllum

|Common in the Chabot Member.

Propora

| More common towards the upper part of the Fox Point Member.

| A heliolitid tabulate coral.

class="wikitable" align="center"
colspan="6" align="center" \| Crinoids
Genus	Species	Presence !Material	Notes	Images
Alopocrinus \| \|Fox Point and Chabot members. \| \| \|
Becsciecrinus \| \|Fox Point and Chabot members. \| \| \|
Dendrocrinus \| \|Chabot Member. \| \| \|
Eumyelodactylus \| \| Fox Point Member. \| \| \|
Euspirocrinus \| \|Fox Point Member. \| \| \|
Protaxocrinus \| \|Fox Point Member. \| \| \|
Xenocrinus \| \|Chabot Member. \| \| \|

class="wikitable" align="center"

colspan="6" align="center" | Crinoids

Genus

Species

Presence

!Material

Notes

Images

Alopocrinus

|Fox Point and Chabot members.

Becsciecrinus

|Fox Point and Chabot members.

Dendrocrinus

|Chabot Member.

Eumyelodactylus

| Fox Point Member.

Euspirocrinus

|Fox Point Member.

Protaxocrinus

|Fox Point Member.

Xenocrinus

|Chabot Member.

colspan="6" align="center" \| Gastropods
class="wikitable" align="center"
Genus	Species	Presence !Material	Notes	Images
Hormotoma \| \| Eastern side of Anticosti Island. \| \| A hormotomid. \|
Subulites \| \|Eastern side of Anticosti Island. \| \|A soleniscid. \|

class="wikitable" align="center"
colspan="6" align="center" \| Graptolites
Genus	Species	Presence !Material	Notes	Images
Climacograptus \|C. typicalis var. atlanticus \| \| \| {{Cite book \|last=Ruedemann \|first=Rudolf \|url=https://books.google.com/books?id=1prnz5SD78kC&dq=climacograptus+becscie&pg=PA441 \|title=Graptolites of North America \|date=1947 \|publisher=Geological Society of America \|isbn=978-0-8137-1019-8 \|language=en}} \|

class="wikitable" align="center"

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

Genus

Species

Presence

!Material

Notes

Images

Climacograptus

|C. typicalis var. atlanticus

| {{Cite book |last=Ruedemann |first=Rudolf |url=https://books.google.com/books?id=1prnz5SD78kC&dq=climacograptus+becscie&pg=PA441 |title=Graptolites of North America |date=1947 |publisher=Geological Society of America |isbn=978-0-8137-1019-8 |language=en}}

colspan="6" align="center" \| Sponges
class="wikitable" align="center"
Genus	Species	Presence !Material	Notes	Images
Clathrodictyon \|C. boreale \| Fox Point and Chabot members. \|"A single small, spheroidal specimen". \| A stromatoporoid. \|
Ecclimadictyon \|E. macrotuberculatum \|Chabot Member. \| \|A stromatoporoid. \|
Pachystylostroma \| \|Very top of the Chabot Member. \| \|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}}

Category:Silurian Quebec

Category:Silurian southern paleotemperate deposits

Category:Ordovician southern paleotropical deposits

Category:Silurian southern paleotropical deposits

Category:Geologic formations of Quebec

Becscie Formation

Description

Fossil content

See also

References