Carbonaceous sediments from tin leads in north-eastern Tasmania have yielded well-preserved and diverse pollen and spore assemblages from the deepest of three stratigraphic units sampled. On the basis of the microfloral assemblages, two biostratigraphic units are recognisable within this one lithologic unit. Comparisons with Tertiary microfloras from Australia, New Zealand and the Kerguelen Archipelago suggest a lower Miocene age overall for the identified assemblages. Some important biogeographic, ecologic and evolutionary factors are briefly discussed.