Late Ordovician mass extinction: A new perspective from stratigraphic sections in central Nevada

Integrated sequence stratigraphic, biostratigraphic, and chemostratigraphic analyses of three stratigraphic sections in central Nevada indicate that Late Ordovician glaciation-induced sea-level fall produced diachronous, stepwise faunal turnover in graptolites, conodonts, chitinozoans, and radiolarians, and also triggered a strong, but transient, positive δ¹³C excursion. This pattern is very different from that described for most mass extinction events.