Amplitudes of Late Pennsylvanian glacioeustasy

The late Paleozoic is well documented as a time of significant continental glaciation, but the extents of the glaciation and attendant glacioeustasy a re not well constrained because precise amplitudes of eustasy are difficult to extract from the stratigraphic record. In this paper, we use preserved relief on ancient subaerial exposure surfaces of large algal bioherms to de monstrate directly that Late Pennsylvanian glacioeustasy reached minimum am plitudes of 80 m and probably exceeded 100 m, Upper Paleozoic algal bioherm s accreted predominantly during sea-level falls, but also during sea-level rises and highstands, and were capable of remarkably rapid growth rates. Eu static amplitudes in excess of 100 m approach amounts documented for the Pl eistocene, and place constraints on models for Gondwanan ice volume, climat e dynamics, acid potential character and magnitude of glacioclimatic fluctu ations.