Predominantly glaciomarine sediments of the Moby Dick Group yielded benthic foraminiferal assemblages of Early Miocene age. The index foraminifera for these deposits are: Cyclammina incisa, C. japonica, Haplophragmoides carinatus and Uvigerinella californica gracilis. Out of 49 foraminiferal species determined, more than half are Recent species. Basing on distribution of calcareous (I) versus arenaceous (II) and mixed (III) foraminiferal assemblages in lithostratigraphic columns of the Moby Dick Group, depth-ranges of the sedimentary basin suggest that the basal part of the Cape Melville Formation is characterized by deep-water arenaceous microfauna which is followed by mixed and calcareous assemblages indicating shallowing up of the basin to depths corresponding to shallow shelf. Higher up in the column, mixed assemblages are followed again by arenaceous ones indicating gradual deepening of the basin to depths comparable with bathyal zone. Two foraminiferal assemblage-zones have been distinguished corresponding to Early Miocene. The foraminifera-bearing sediments pre-date an intrusive event of andesite dyke swarm K/Ar dated at approx 20Ma.-from Authors Inst of Geol Sci, Polish Acad of Sci, ul Senacka 3, 31-002 Krakow, Poland.