The late devonian (Frasnian/Famenian) mass extinction: A proposed test of the glaciation hypothesis

In this paper it is agued that Late Frasnian global cooling was the first step in the on set of the Late Paleozoic Ice Age, and that a Late Frasnian glaciation existed that was analogous to the early Oligocene (Oi-1) glaciation that took place in the first step of global cooling in the on set of the Cenozoic Ice Age. It is here pro posed that definitive sedimentological evidence for the existence of Late Frasnian glaciation, like the Oi-1 glaciation, would be the discovery of ice-rafted debris in marine sediments of Late Frasnian age similar to the ice-rafted debris found in Oi-1 marine sediments (Zachos et al., 1992; Ehrmann and Mackensen, 1992). Rather than metre- to decimetre-sized ice-rafted debris, a search should be initiated for the presence of sand-sized (>250 jm) ice-rafted debris in Frasnian marine strata located off shore from the main Gondwana land mass, and dated to the Laterhenana Conodont Zone and/or to the linguiformis-Early triangularis cono dont zonal in ter val where the extinctions and sharp drops in sea-sur face tem per a ture oc curred (Joachimski and Buggisch, 2002).