TESTING THE CORRELATION OF THE FRASNIAN/FAMENNIAN BOUNDARY (LATE DEVONIAN) IN SHALLOW WATER PALEOENVIRONMENTS IN NEW YORK

The Frasnian/Famennian (F/F) boundary was identified using conodont biostratigraphy in deep-water strata in western New York by Over (1997). The boundary occurs in the upper Java Formation (Hanover Shale), just below the base of the Dunkirk Shale. During the mapping of the state, the Java-Dunkirk contact has been correlated into shallower-water Chemung paleoenvironments using lithostratigraphy; this contact should mark the approximate position of the F/F boundary in shallow marine strata. Previously, we have discussed new biostratigraphic evidence regarding the position of the F/F boundary in Chemung facies: some Frasnian taxa extend into beds mapped as Famennian (e.g., Spinatrypa and Palmetolepis winchellii). This could indicate miscorrelation of the F/F boundary interval between shallow and deep water or the survival of ostensibly Frasnian taxa beyond the F/F extinction. We discuss further tests of the geochronology of this interval using chemostratigraphy and well-log data. This work will be critical in comparing the timing of Late Devonian extinction events in New York and Pennsylvania with those worldwide.