Revising the Frasnian–Famennian Devonian Boundary and Kellwasser Events

Revised correlation of the Frasnian–Famennian boundary and Kellwasser Events (Upper Devonian) in shallow marine paleoenvironments of New York State

Authors:

Bush et al

Abstract:

The Frasnian–Famennian boundary (Upper Devonian) is exposed in a 200 km-long outcrop belt in New York State, with deeper paleoenvironments to the west and shallower ones to the east. Geochronology in the eastern end of the outcrop belt has been based primarily on lithostratigraphic correlation with western sections, which were dated using conodonts. We collected conodonts and brachiopods from several measured sections and numerous other localities, and these collections suggest that these east–west lithostratigraphic correlations require revision. We correlate the Wiscoy Formation with the upper Angola Formation and the Canaseraga with the upper Hanover. Thus, the Canaseraga Formation contains the Frasnian–Famennian boundary and Upper Kellwasser Event, and the dark shale above the Wiscoy is equivalent to the Pipe Creek Formation and Lower Kellwasser Event. These new correlations imply that the Lower Kellwasser Event had greater impact on the shelly benthos of New York than the Upper Kellwasser, at least for the subset of taxa examined here. All strophomenid brachiopods and rugose corals were extirpated at the Lower Kellwasser, along with numerous other brachiopods. The final species of atrypid brachiopod persisted to the Upper Kellwasser.