Location

Energia’s Gawler Project includes six granted Exploration Licences (EL’s), two located along the northwest trending “Olympic Dam corridor” and four along the northeastern boundary of the Craton, in what is interpreted by Energia’s geophysical consultants to be a geologically similar corridor (Figure 8).

The Tenements were selected after a regional prospectivity modelling exercise. The main targets are uranium-bearing IOCG deposits like the giant Olympic Dam. However, there is also potential in the tenements for sandstone-hosted uranium deposits (like the nearby operating Honeymoon and Beverley deposits) as well as for unconformity-related deposits associated with the extensive Mesoproterozoic, Neoproterozoic and Phanerozoic platform cover sediments (some of these sequences are known to contain important sediment-hosted copper deposits, a known associate with uranium systems elsewhere).

Figure 8. Location plan of the South Australian Projects

The Tenements mostly lie within flat and sparsely vegetated arid savannah to desert. There are few tracks, though off-road access is generally possible except in areas of dune sands.

Access into the region is excellent by way of sealed all-weather roads from Adelaide via Port Augusta to Olympic Dam and Coober Pedy.

Project Geology and Exploration History

Exploration for IOCG deposits in covered areas like the Gawler Craton relies heavily on geophysical modelling and interpretation of gravity and magnetic data, in order to detect coincident dense alteration patterns associated with major structures, followed by scout drilling of targets. While numerous companies have held tenure over parts of the existing tenements there are few previous drill holes to basement.

Prospective areas are within the basement rocks in and around oxidized and altered granitic intrusives of the Hiltaba suite, emplaced about 1600-1550Ma into Palaeoproterozoic and possibly Archaean metamorphic sequences. Much of the region is covered by younger sediments, in some cases up to 800m or more thick. Cost-effective exploration therefore requires prioritization of targets according to interpreted depth of cover.

Detailed ground gravity and geophysical modelling has been completed over selected targets on the tenements. On Balta Baltana (EL3682) several coincident magnetic and gravity features have been evaluated and downgraded. However, one of these “BB1” (6793300N 549900E) has been modelled as a drilling target at depths of 250-350m. Similarly, in the Lake Eyre tenements three discrete targets have been outlined to date, namely “LE4”on EL3958, “LE2”on EL3957 and “LE1”on EL3650 (Figure 9).

On Blyth Creek (EL3680) gravity data collected to date is not yet of sufficient density to define targets but several discrete gravity highs occur in a north-south orientation, at a high angle to the structural grain evident on magnetic imagery. These will be priority areas for infill ground gravity surveys.

Figure 9. Lake Eyre Tenements – location of gravity anomalies on magnetic image