Conodont-Based Correlations of Lower and Middle Ordovician Strata in Western Newfoundland
Lower and Middle Ordovician conodont faunas from the Table Head Formation and the Cow Head Group in western Newfoundland to a large extent, or in some cases exclusively, contain forms that occur in the Balto-Scandian sequence, thus facilitating a correlation between the northern Applachians and Balto-Scandia. The lower boundary of the Table Head Formation probably lies within strata corresponding to the British Didymograptus bifidus Zone and corresponds to a level tentatively regarded as at the base of the Aluoja Substage. The upper boundary of the middle Table Head corresponds to a rather high level in the Lasnamagi Stage (in the upper part of the Didymograptus murchisoni Zone). The upper Table Head consists of black graptolitiferous shales, which have not been searched for conodont elements. Studies of conodonts from the Table Head, the Cow Head Group, and the uppermost part of the St. George Formation, and comparisons with published and nonpublished accounts of conodonts from the Fort Pena, the Joins and the Levis Formations, indicate that the North American bifidus Zone is at least partly equivalent to the British bifidus Zone, hence supporting the correlation suggested by Berry (1960).