MUTCH, ANIKA J. and PETER R. VAIL
Rice University, Houston, TX

Abstract: A Sequence Stratigraphic Analysis of an Oligo-Miocene Carbonate Platform; Beagle and Northern Dampier Subbasins of the Carnarvon Basin, Northwest Shelf of Australia

Sequence Stratigraphic global cycle charts (Haq et. al, 1987, Haardenbol et al, 1998) are especially useful in chronostratigraphic analysis of stratigraphic sections. According to Haq et. al and Haardenbol et. al, sequence boundaries are synchronous when dated at their correlative conformities.

To test this hypothesis, a sequence stratigraphic analysis was performed on an Oligo-Miocene carbonate platform from the Northwest Shelf of Australia. The identified sequence boundaries and their associated maximum flooding surfaces were age dated with new nannofossil and previously established foram biostratigraphy. The sequence stratigraphic analysis is presented on stratigraphic cross sections and chronostratigraphic sections. The ages from these sections are compared to two well-dated northern hemisphere locations; the Bahamas carbonate platform and the offshore New Jersey siliciclastic shelf.

The Oligocene and Miocene sequences on the Haardenbol et. al, 1998 global cycle chart are notably different from the Haq et. al, 1987 cycle chart; two additional Lower Miocene sequences have been assigned in the Haardenbol et. al chart at 18.7 ma and 19.5 ma, and all sequence boundary ages have been revised using recent biostratigraphic analysis in conjunction with the Berggren 1995 time scale. The Australian sequence stratigraphic analysis attempts to reconcile the additional sequences and compare the ages of the Australian sequences to the global cycle charts.

AAPG Search and Discovery Article #90928©1999 AAPG Annual Convention, San Antonio, Texas