The Verulam Formation belongs to the Simcoe Group in South-central Ontario and to the Trenton Group in Southwestern Ontario. Within the Simcoe Group, it overlies the Bobcaygeon Formation. Both the Bobcaygeon and Verulam Formations are composed of bioclastic wackestones, grainstones, and packstones interbedded with calcareousshales and siltstones. The Verulam contains more shale than the underlying Bobcaygeon Formation. Several hardgrounds have been documented in detail from the upper Bobcaygeon and lower Verulam. The paleoenvironments in which the Bobcaygeon and Verulam Formations were deposited have been interpreted as a proximal carbonate shelf that ranged in depth and proximity from shoal to shallow shelf in the Bobcaygeon and from deep shelf to shoal or shallow shelf in the Verulam Formation.[2]
Fossil content
The Verulam Formation and the underlying Bobcaygeon Formation have provided many fossils. Both formations form the Brechin Lagerstätte, a Lagerstätte of excellent preservation of numerous exceptionally preserved crinoid specimens with arms, stems, and attachment structures intact.[2][3][4] Also ostracods, trilobites, bivalves, gastropods, cephalopods and other fossils were found in the formation.[5]
Cole, Selina R.; Wright, D.F.; Ausich, W. I.; Koniecki, J. M. (2020), "Paleocommunity composition, relative abundance, and new camerate crinoids from the Brechin Lagerstätte (Upper Ordovician)", Journal of Paleontology, 94 (6): 1103–1123, Bibcode:2020JPal...94.1103C, doi:10.1017/jpa.2020.32
Cole, S.R.; Ausich, W.I.; Wright, D.F.; Koniecki, J.M. (2018), "An echinoderm Lagerstätte from the Upper Ordovician (Katian), Ontario: taxonomic re-evaluation and description of new dicyclic camerate crinoids", Journal of Paleontology, x (3): 1–18, Bibcode:2018JPal...92..488C, doi:10.1017/jpa.2017.151
Peters, S.E (2003), Evenness, richness and the Cambrian-Paleozoic faunal transition in North America: an assemblage-level perspective, University of Chicago, pp. 1–279
Wilson, A.E (1951), "Gastropoda and Conularida of the Ottawa Formation of the Ottawa - St. Lawrence Lowland", Geological Survey of Canada Bulletin, 17: 1–149
