The Eucla basement project was set up to study the poorly understood provinces between the eastern edge of the Albany–Fraser Orogen in Western Australia and the western margin of the Gawler Craton in South Australia.
In Western Australia, the Eucla basement includes the Madura Province and the Forrest Zone of the Coompana Province. These provinces are Precambrian in age and covered by up to 300 metres of younger sedimentary rocks that are part of the Madura Shelf, deposited during the Cretaceous.
On top of this, there is up to 200 metres of limestone laid down in the Eucla Basin during the Eocene, forming the flat Nullarbor Plain. Because none of the older Precambrian rocks are visible on the surface, we rely on geophysical data and samples from drillcores to study the area.
The Eucla basement stratigraphic drilling program, funded by the Exploration Incentive Scheme (EIS), collected high-quality diamond drillcores from well-mapped geophysical zones. The drilling program provided a lot of new information about the hidden basement provinces, which are key to understanding the Proterozoic geology of Australia.
Studying these drillcores, along with company cores donated or co-funded by the EIS, gives us information about the potential for valuable minerals in the vast area beneath the Nullarbor Plain.
The project has also provided valuable experience in, and information about, drilling in the difficult conditions of the Nullarbor region. Different methods were tested like RC (reverse circulation) drilling and mud-rotary drilling to see which works best for breaking through the surface. Basement rocks lie between 250 and 440 metres below the surface.
Published data on the Eucla basement project
Results from the Eucla basement project can be found through the DEMIRS eBookshop and academic journals.
Eucla basement stratigraphic drilling results release workshop: extended abstracts
