Wilson Loc 209. L’Orignal (Ordovician of Canada)

Where: Ontario, Canada (45.6° N, 74.7° W: paleocoordinates 25.6° S, 51.5° W)

• coordinate based on political unit

• outcrop-level geographic resolution

When: Phragmodus undatus graptolite zone, Hull Formation, Turinian (460.9 - 449.5 Ma)

• Hull is sometimes considered an extension of the upper Bobcaygeon. However, recent consensus is to make the Hull its own formation. The Hull overlies the Rockland and underlies the Verulam. Phragmodus undatus conodont zone (Uyeno 1974) & Diplograptus multidens graptolite zone (Dix & Al-Dulami 2011)

• formation-level stratigraphic resolution

Environment/lithology: sand shoal; lithified, shelly/skeletal grainstone

• Barrier-front deposits consist of predominantly crinoid-bryozoan grainstone with a suite of sedimentary structures indicative of a lower to middle shoreface setting (planar laminae, cross-laminae, rare HCS and a mixed Skolithos-Cruziana ichnofauna). The barrier-top facies consist of closely juxtaposed very high- and low-energy deposits, representing barred upper shoreface to beach environments and slackpond or intertidal mudflat. The high-energy facies consist of bryozoan-pelecypod-Solenopora-oncoid grainstone and rudstone. Sedimentary structures include low-angle, truncating planar laminae and locally dense clusters of small Skolithos burrows. Low-energy deposits are sparsely fossiliferous (ostracodes, green algae, gastropods and Tetradium) calcisiltite with probable fenestrae and very rare desiccation cracks. Small (<50 cm deep), storm-breach channels filled by bioclastic-intraclastic rudstone are incised into the calcisiltite. Most of the lagoon deposits are Tetradium and green algae-rich mudstones. Pelloidal grainstone are interpreted as representing small sand shoals/beaches around the fringes of the lagoon. Lenses of bioclastic-intraclastic rudstone, with grain-types characteristic of both the barrier-top and lagoon, are interpreted as storm washover deposits. (Kiernan & Dix 2002. The Hull Limestone (Upper Ordovician) of Eastern Ontario: A Lower Paleozoic Carbonate Barrier-and-Lagoon System)

Size class: macrofossils

Reposited in the GSC

Primary reference: A. E. Wilson. 1951. Gastropoda and Conularida of the Ottawa Formation of the Ottawa - St. Lawrence Lowland. Geological Survey of Canada Bulletin 17:1-149 [P. Wagner/P. Wagner/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 185356: authorized by Pete Wagner, entered by Pete Wagner on 19.04.2017

Creative Commons license: CC BY (attribution)

Taxonomic list

 Euomphalina - Holopeidae
"Holopea nereis" = Haplospira nereis
"Holopea nereis" = Haplospira nereis Billings 1865 snail
 Bellerophontida - Sinuitidae
Sinuites cancellatus Hall 1847 snail
 Murchisoniina - Subulitidae
Cyrtospira parvula Billings 1865 snail