Chronostratigraphic accuracy of Ordovician ecostratigraphic correlation

Six stratigraphic sections along a 34 km transect down a Middle Ordovician depth gradient (Trenton Group, New York) were ecostratigraphically correlated to 10⁵ year accuracy by pairwise statistical cross-correlation of curves describing each section's depth history in terms of the distribution of fossil marine benthic communities along the gradient. This accuracy is about an order of magnitude greater than that of ordinary biostratigraphic correlation in the sequence, and it is attained even in correlating between very different biofacies. New ecostratigraphic methods illustrated here promise comparable improvements in analyzing many stratigraphic sequences.