Petroleum source rocks of the Amadeus Basin

Sediment cores from exploration and stratigraphic boreholes in the Amadeus Basin were examined for information about the distribution, quality and distinctiveness of source rock intervals. Significant intervals of mature and moderate to rich source rock were confined to one unit, the Ordovician Horn Valley Siltstone. Organic matter was present in the Cambrian Chandler Formation and in the Proterozoic Pertatataka and Bitter Springs Formations. Rock-Eval pyrolysis and biomarker distributions suggest that the organic matter in the Cambrian and Proterozoic sediments, where it does exist, is mature with respect to petroleum generation. High temperature thresholds are probably necessary for hydrocarbon generation from the Ordivician kerogens of the Horn Valley Siltstone. -from Authors