THE SEISMIC EXPRESSION OF MIDDLE TO UPPER DEVONIAN REEF COMPLEXES, CANNING BASIN

Abstract

This paper describes the unique seismic character of the Middle to Upper Devonian Pillara Limestone buildups as seen on seismic data acquired in the area northeast of the Pillara Ranges in the northern Canning Basin. The combination of high resolution 'vibroseis' acquisition techniques and relatively shallow depth of burial has enabled previously unattained definition of the reefs and the seismic facies variation associated with them. The lower bank, upper platform, fore- and back-reef facies and sediments of the overlying basinal flooding phase can be identified. The interpretation has been supported by the drilling of two exploration wells which have provided geological control in the subsurface.A model for the growth of the carbonate buildups and the relationship of this growth history to key phases of tectonism in the area has been developed from stratigraphic studies.A comparison with previous models for Devonian reef complexes in the Pillara is also presented.