Havilah Resources Ltd (ASX:HAV) has received encouraging results of up to 20 metres at 6.3 g/t gold in shallow drilling at West Kalkaroo prospect near the Kalkaroo Copper-Gold Project in northeast South Australia.
The results are from the first round of gold resource drilling at West Kalkaroo which was carried out by Havilah’s drilling crew using the aircore (AC) drilling method.
This method is suited to clayey material and soft decomposed rock and the horizontal, clay-hosted base of Tertiary gold mineralisation was confirmed in several aircore drill holes, including 2 metres at 2.9 g/t.
Havilah’s technical director Dr Chris Giles said: “It is pleasing that the base of Tertiary gold mineralisation persists at this location. Also, that the saprolite gold mineralisation was intersected where predicted with very good grades and widths.”
Shares were as much as 30% higher to 12 cents intra-day, up from 5.3 cents at close on March 13.
The specific objectives of the program are to define a gold resource in Tertiary age Namba Formation clays and to better define the underlying saprolite gold mineralisation within the confines of a conceptual starter open pit at West Kalkaroo.
Clay-hosted, base of Tertiary assay results include:
- 2 metres at 2.9 g/t from 29-31 metres downhole; and
- 9 metres at 0.61 g/t from 32-41 metres downhole.
Results in ‘waste’ clay
These results occur in what would normally be considered as waste clay overburden material that must be removed to access the underlying copper-gold ore body.
It is thought that gold in these clays is secondary, having migrated upwards in acidic groundwater from the underlying primary bedrock gold mineralisation before depositing in the more carbonaceous and reduced Namba clay layers near the base of Tertiary age sediments.
Aircore drilling is being undertaken within the confines of the conceptual starter open pit at West Kalkaroo (light blue) and is targeting both the base of Tertiary gold mineralisation (dark blue) and underlying saprolite gold mineralisation (yellow).
All aircore drill holes were continued into the underlying saprolite gold and native copper zones until the rock became too hard for the aircore blade bit to penetrate further.
Results from the saprolite gold and native copper zones include:
- 20 metres at 6.3 g/t from 77-97 metres downhole and 10.5 metres at 1.8 g/t from 104-114.5 metres downhole (in native copper zone);
- 12 metres at 1.1 g/t from 89-101 metres downhole (in native copper zone); and
- 2 metres at 19 g/t from 60-62 metres downhole.
The 20-metre intersection is more than double the average gold grades obtained in saprolite gold intersections in nearby earlier drill holes.
This highlights the importance of further drilling to obtain more confidence in the saprolite gold grades, which are typically quite variable.
Intersections in the underlying native copper zone will be assayed for copper and other elements, eg rare earth elements, at a later date.
Giles said: “We are fortunate to have been able to keep drilling through this very challenging period, which is partly a function of managing our own drilling operations and also having our own exploration base camp to operate from at Kalkaroo, a remote and isolated location in northeast South Australia.
“Subject to COVID-19 directives, Havilah plans to continue with its shallow gold resource exploration drilling at Kalkaroo for the foreseeable future.”