New biostratigraphic and chemostratigraphic data from the Chicotte Formation (Llandovery, Anticosti Island, Laurentia) compared with the Viki core (Estonia, Baltica)

Due to the lack of biostratigraphically useful graptolites in the crinoidal and reefal Chicotte Formation on Anticosti Island (Québec, Canada), the precise chronostratigraphic position of the formation is not known. New stable carbon isotope and conodont data and a comparison with the detailed conodont distribution and d13C development in the Viki core (Estonia) suggest an early Telychian age (Pterospathodus eopennatus to P. a. angulatus zones) for at least the lower half of the formation. This interval is characterized by a small but distinct positive excursion in d13C, with peak values of + 3.2‰ and + 2.8‰ VPDB in the lowermost 10–15 m of the Chicotte Formation on Anticosti and in the Viki core, respectively.