Cyclostratigraphy and Astrochronology of the Late Devonian Kellwasser Crisis, Northern Appalachian Basin, USA

Abstract

Late Devonian marine mass extinctions associated with the Frasnian-Famennian stage transition (approximately 370 million years ago) occurred in a succession of extinction pulses within a narrow stratigraphic interval known as the Kellwasser Crisis. In most localities, this interval is typically only meters thick, but an expanded, 32 m thick cyclic marine sedimentary section at Walnut Creek, Chautauqua County, New York, USA permits investigation of the Kellwasser Crisis interval at an unprecedented high resolution. Visible cyclicity within the section strongly suggests the presence of Milankovitch cycles, which are globally correlatable and can be used to develop an accurate duration for this crucial extinction period. Astrochronology developed from this section will be used to investigate changes in climate forcing mechanisms driven by Milankovitch cycles, and to reduce uncertainty in the Late Devonian timescale.