HOW ANOXIC IS THE KELLWASSER EVENT IN NEW YORK STATE? EVIDENCE FROM PALEONTOLOGICAL AND GEOCHEMICAL PROXIES

The Kellwasser Event is a globally recognized event that is widely thought to be persistently anoxic, associated with major biological turnover and is commonly expressed as black shale. The Kellwasser equivalent has been recognized in Late Devonian aged strata that are easily accessed in upstate New York and provide an opportunity to test the extent and persistence of anoxia through this interval. At six localities in western New York nearly 100 samples were collected from intervals below, through, and above the Frasnian-Famennian boundary, and through the identified Kellwasser event interval. Relative oxygen levels are recognized in these samples using ichnological methods on a microstratigraphic scale, specifically size and relative amount of bioturbation. Associated with these data, samples were processed for geochemical analysis. Paleoredox proxies including trace metal concentrations of Cr, Mo, Mn, U, and V as well as TOC values were selected as they are widely used to recognize variations in ancient paleoredox conditions. The combination of these proxies reveal a high resolution record of the dynamic oxygen history before, during and after the Frasnian-Famennian extinction event.