A re-evaluation of the Lower to Middle Triassic on the Candace Terrace, Northern Carnarvon Basin

Abstract

The Lower to Middle Triassic mixed carbonate–clastic system in the Northern Carnarvon Basin is poorly understood relative to the stratigraphically younger Jurassic play systems. Few well penetrations and a lack of quality seismic data have deterred exploration of this interval for many years. In recent times, the Lower to Middle Triassic source potential has been comprehensively de-risked within the Roebuck Basin, with subsequent implications across the entire North West Shelf of Australia, opening up the possibility of an entirely new regional play fairway. This paper focuses on the Candace Terrace, on the southern flank of the Carnarvon Basin, where seismic observations and interpretations of Lower to Middle Triassic submarine canyon systems have been made. The stratigraphic elements of this play interval can now be more clearly observed with the aid of 3D seismic data. Amplitude extractions show the internal geometries of these highly erosive systems are sinuous, compensating flows. The aims of this paper are to postulate the stratigraphy of the Lower to Middle Triassic on the Candace Terrace, highlight the tectonic cause of the canyon systems and discuss the prospectivity of the observed turbidite features.