A NEW PLAY IN THE GIPPSLAND BASIN

Abstract

Explorers of the Cippsland Basin have generally assumed that the prospective Latrobe Group (Late Cretaceous to Eocene) is separated from the Strzelecki Group (Early Cretaceous) by an angular unconformity dated at about 100 million years before present (Ma). Thus all sub-unconformity traps seen on seismic sections have been assumed to be developed in the unprospective Strzelecki Group. Evidence from seismic sections and wells indicates that this unconformity should be dated at about 80 Ma. The beds deposited between 80 and 100 Ma are part of the Late Cretaceous Latrobe Group and have the potential for both reservoirs and intraformational seals.

This new sub-unconformity play can be pursued in areas transitional between the Central Deep and the flanking platforms. On the platforms the prospective beds are absent because of truncation while in the Central Deep they are beyond the reach of the drill.