A sequence stratigraphic analysis of an Oligocene to Miocene carbonate platform: Beagle and northern Dampier subbasins, Australia
Mutch, Anika Jan
Vail, Peter R.
Master of Arts
This sequence stratigraphic analysis examines an Oligocene to Miocene carbonate platform from the Northwest Shelf of Australia. Five Oligocene sequences, eleven Miocene sequences and one Pliocene sequence are identified with the aid of seismic, well logs, and biostratigraphy. To test the global nature of these sequences, their ages are compared to Europe, New Jersey, and the Bahamas. Most sequences correspond well, within a few hundred thousand years, with the exception of five sequences 32.0 Ma, 29.4 Ma, 20.5 Ma, 19.5 Ma, and 17.3 Ma (listed with European ages) that are not found in Australia. The global correlations and oxygen isotopes from an industry well suggest that eustasy is the primary control on the genesis of Oligocene to mid-Miocene sequences. Sequence boundaries correlate to heavy delta18O peaks while maximum flooding surfaces coincide with light delta18 O peaks.