Integrated sequence stratigraphic, biostratigraphic, and chemostratigraphic
analyses of three stratigraphic sections in central Nevada indicate that L
ate Ordovician glaciation-induced sea-level fall produced diachronous, step
wise faunal turnover in graptolites, conodonts, chitinozoans, and radiolari
ans, and also triggered a strong, but transient, positive delta(13)C excurs
ion. This pattern is very different from that described for most mass extin
ction events.