An Early Cainozoic (Paleocene) foraminiferal fauna with Fabiania from offshore eastern Australia

Abstract

Early Paleocene marine sediments are recorded from a single dredge sample taken from the continental slope (3533–3306 m) off the central coast of New South Wales. They probably belong to the Early Paleocene NP4 calcareous nannoplankton zone (P1c or P1d/P2 in standard formainiferal zonal terms) and thus are the first Palaeogene marine rocks known from the region and the first record of marine biota of this age from the Australian margin other than Western Australia. The age is based on analysis of calcareous nannofossils. The sediment accumulated in very shallow, warm, fully marine conditions, apparently off a coast of periodically low runoff, and the fauna lacks any planktonic foraminiferal species. While it is domainated by several typically Paleocene benthic forms well known from southern and southwestern Australia, several otherwise typical Australian forms appear to be absent. Fabiania (the new species F. macgowrani) is recorded for the first time from Australia, apparently the earliest known occurrence of the genus.

Paleocene rocks of this age are also known from the Perth Basin and Northwest Shelf of Western Australia and it seems these indicate the need for recognition of a new sedimentation cycle in the Cainozoic of Australia.

Key words:

• Paleocene
• Foraminifera
• Fabiania
• Tasman Sea
• eastern Australia