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We present the first description of organic-walled microfossils from Cambrian strata of the Bourinot belt, central Cape Breton Island. Age-diagnostic acritarchs have been recovered from the Dugald and MacMullin formations and from probable levels within the upper part of the Eskasoni Formation, which permit detailed correlations with acritarch-based zones in Newfoundland and Spain. The assemblage of acritarchs from the Dugald Formation confirms earlier assignments to the early middle Cambrian eteminicus Zone, but it also indicates that the upper part of the formation belongs to the hicksi Zone of the Drumian Stage. Acritarchs from the MacMullin Formation provide the first biostratigraphic evidence that this unit extends into the forchhammeri Zone of the Guzhangian Stage. These acritarchs are present in the lower part of the MacMullin Formation, putting into question earlier identification of hicksi Zone trilobites in this unit and raising the possibility of an unconformity. The data from the Bourinot belt provide additional evidence for the biostratigraphic utility of acritarchs in the Cambrian Acado-Baltic province. [ABSTRACT FROM AUTHOR]

Abstract: We present here the results of a pilot study on Cambrian acritarchs from Cape Breton Island, Nova Scotia, based on a material from the MacLean Brook Formation in the Mira River Valley. An assemblage from the base of the formation contains 8 species including Eliasum llaniscum, Cristallinium dubium and Symplassosphaeridium cambriense, and correlates with a position close to the Paradoxides davidis–P. forchhammeri Zone boundary. An assemblage from the upper part of the formation contains 16 species, of which 3 are new, including Cristallinium aciculatum, Petaloferidium lacrimiferum n. sp., Pirea orbicularis, Stelliferidium pingiculum, S. magnum n. sp., S. albanii n.sp, and Timofeevia microretis, correlated to the Olenus Zone. The upper assemblage is particularly noteworthy as it provides the first direct evidence for the Olenus Zone in the MacLean Brook Formation. Furthermore, it contains stratigraphically significant taxa known from sections on Baltica, and northern Gondwana but which have not been reported previously on Avalonia. The distinction between Stelliferidium and Timofeevia is discussed in part based on new data on Timofeevia lancarae from its type area in northern Spain. It is suggested that many reports of Furongian Timofeevia phosphoritica and T. lancarae are better referred to Stelliferidium. [Copyright &y& Elsevier]