ABSTRACT: Petroleum Potential of the Arafura Basin

BRADSHAW, JOHN, and AIDAN M. G. MOORE, Bureau of Mineral Resources, Canberra, Australian Capital Territory, Australia

The Arafura basin is on the northern margin of Australia extending north toward New Guinea, and contains a thick Cambrian to Permian-Triassic sedimentary sequence. The basin lies in shallow water and consists of a northern platform, a northwest-trending graben, the Goulburn graben, and a southern platform that extends onshore. The basin is underlain by Proterozoic sediments equivalent to the onshore McArthur basin and overlain by the Mesozoic Money shoal and Carpentaria basins. Exploration has been concentrated in the graben where encouragement includes over 400 m of continuous oil shows in the Devonian and Ordovician, and oil-mature Cambrian units with up to 8.5% total organic carbon. A recently acquired regional grid of 12-s seismic defined a thick Paleozoic and Proterozoic section orth of the graben indicating that exploration could be extended to the north and east. This northern sequence is basinal shaped with a gentle synclinal axis running northwest to southeast, and contains northward dipping fault blocks that extend from the graben to the Australian/Indonesian border. On the southern platform, tilted Proterozoic fault blocks sole out on a northward dipping detachment. The graben has a northwest to southeast alignment with very steep faults, and differs significantly from faults in the Proterozoic, which strike east-west and dip at 60 degrees to the north. Regional gravity data (Seasat) mimics thickening trends in the Proterozoic and perhaps the trends of igneous basement, showing two north-south highs with an intervening low.

AAPG Search and Discovery Article #91015©1992 AAPG International Conference, Sydney, N.S.W., Australia, August 2-5, 1992 (2009)