Hiatus distributions and mass extinctions at the Cretaceous/Tertiary boundary

Much disagreement over the interpretation of data bearing on various Cretaceous/Tertiary (K/T) extinction scenarios results from a failure to view these data within their appropriate stratigraphic context. Combined biostratigraphic and chronostratigraphic analyses of K/T boundary sequences have revealed systematic differences in patterns of sediment accumulation within continental-shelf and deep-sea depositional settings. This differential pattern of sediment accumulation can be related to the lates Maastrichtian-earliest Danian sea-level rise. Our data suggests that the abrupt shifts in carbon-isotope abundances, single-peak Ir anomalies, and apparently instantaneous mass extinctions of marine plankton may be artifacts of a temporally incomplete (or extremely condensed) deep-sea stratigraphic record. -from Authors