NEOCOMIAN EUSTATIC CHANGES — BIOSTRATIGRAPHIC EVIDENCE FROM THE CARNARVON BASIN

Abstract

A fall in sea level of approximately 200m affected the northern Carnarvon Basin of Western Australia during the earliest Neocomian. This was followed by a brief lowstand and then a basin-wide flooding beginning in the Late Valanginian or Early Hauterivian. Maps showing the pattern of inundation as the sea level rose reflect the palaeotopography of the basin at the time. These maps are derived from the age of the base of the onlapping sequence, namely the Winning Group. The ages are based on a palynological zonation of the Neocomian to Early Aptian.