In this pa per it is agued that Late Frasnian global cool ing was the first step in the on set of the Late Pa leo zoic Ice Age, and that a Late Frasnian gla ci ation ex isted that was anal o gous to the early Oligocene (Oi-1) gla ci ation that took place in the first step of global cool ing in the on set of the Ce no zoic Ice Age. It is here pro posed that de fin i tive sedimentological ev i dence for the exis tence of Late Frasnian gla ci ation, like the Oi-1 gla ci ation, would be the dis cov ery of ice-rafted de bris in ma rine sed i ments of Late Frasnian age sim i lar to the ice-rafted de bris found in Oi-1 ma rine sed i ments (Zachos et al., 1992;Ehrmann and Mackensen, 1992). Rather than metre-to decimetre-sized ice-rafted de bris, a search should be ini ti ated for the pres ence of sand-sized (>250 mm) ice-rafted de bris in Frasnian ma rine strata lo cated off shore from the main Gond wana land mass, and dated to the Late rhenana Cono dont Zone and/or to the linguiformis-Early triangularis cono dont zonal in ter val where the extinc tions and sharp drops in sea-sur face tem per a ture oc curred (Joachimski and Buggisch, 2002).