Where: Ontario, Canada (45.6° N, 74.8° W: paleocoordinates 25.6° S, 51.5° W)
• coordinate based on political unit
• outcrop-level geographic resolution
When: L'Orignal Formation, Turinian (457.3 - 453.8 Ma)
• L'Orignal defined by Oruche et al. and includes Leary-Rockland beds of Wilson
• 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 197158: authorized by Pete Wagner, entered by Pete Wagner on 24.10.2018
Creative Commons license: CC BY (attribution)
Taxonomic list
Show authors, comments, and common names
Gastropoda |
Bellerophontida - Plectonotidae |
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Bellerophontida - Sinuitidae |
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Tergomya |
Cyrtonellida - Cyrtolitidae |
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