Seismic Stratigraphy of Devonian Reef Complexes, Northern Canning Basin, Western Australia

Abstract

Seismic stratigraphic modeling of the Devonian reef complexes of the northern Canning basin suggests that the model of reef development proposed by Playford can be applied judiciously to the subsurface reefs. Playford proposed, based on outcrop geology, that reef development occurred on the edge of upright, backstepping platforms during the Frasnian and on the edge of advancing platforms during the Famennian. The modeling shows four diagnostic characteristics: (1) tuned trough-on-peak seismic wavelet character of the advanced Famennian reefs, (2) distinct trough wavelet character of backstepped Frasnian platform (underlying the advancing reefs), (3) local dips on migrated seismic data that can be correlated with marginal-slope facies, and (4) pull-up on seismic sections beneath the carbonate buildups. The most useful of these characteristics is the trough-on-peak wavelet pattern defining the front of the Famennian reefs. As the Famennian back-reef facies is a known hydrocarbon reservoir, the trough-on-peak pattern can provide valuable clues to the Famennian reef geometry.