Money Shoal Basin

Basin Details and Geological Overview

The Jurassic to Cainozoic Money Shoal Basin is a mainly offshore basin located off the Northern Territory coastline. The basin is a tilted passive margin basin with no specific depocentre and contains formations that are generally monoclinal and undeformed.

The base of the sedimentary succession ranges in age from Middle Jurassic in the west to Late Cretaceous in the east. These sediments unconformably overlie the Arafura Basin and Pre-Cambrian rocks of the Pine Creek Geosyncline and McArthur Basin. Sediments were deposited in marine environments, with occasional incursions of deltaic and fluvial sediments and are up to 4500 metres thick in the northwest but thin rapidly eastwards.

The basin is bound to the west by the Lynedoch Fault System, separating the Money Shoal Basin from the Calder and Malita Grabens, and bound to the east by a Mesozoic hinge, which separates the Money Shoal Basin from the Carpentaria Basin. The southern basin boundary is represented by onshore sediment pinchout. Little is known about the northern portion of the basin, which extends beyond the Australian-Indonesian seabed boundary.

Nine petroleum exploration wells have been drilled in the offshore Money Shoal Basin, all in the region of the underlying Goulburn Graben. Jurassic claystones interbedded with sandstones are considered to be source rocks of good quality, with the potential to generate oil and gas. Marginally mature Early Cretaceous claystones also exist. Sandstones of the Money Shoal Basin have good reservoir qualities and exist at various stratigraphic levels. Jurassic and Early Cretaceous sandstones of the basin have good porosities, whereas Palaeozoic reservoirs tend to be of low porosity. These sandstones are not always overlain by seal-quality claystones and therefore the prime exploration risk within the Money Shoal Basin appears to be poor vertical seals.

• Prove Explorer – Money Shoal Basin Details and Geological Overview

Key references