Havilah Resources Ltd (ASX:HAV) has further boosted the commercial potential of its West Kalkaroo project in South Australia after receiving high-grade gold results from ongoing shallow gold resource drilling.
The company aims 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.
Highly encouraging new results include 5 metres at 4.56 g/t gold from 50 metres and 3 metres at 5.51 g/t from 56 metres.
“Consistently positive results”
Havilah technical director Dr Chris Giles said: “Once again the West Kalkaroo gold drilling results continue to be consistently positive.
“Good gold grades have been returned in the base of Tertiary clays, which has confirmed the eastern extensions of this persistently gold mineralised, shallow clay layer.
“A further repeat of better than published resource grades for the saprolite gold ore is also positive for the conceptual starter open pit economics.”
The company is examining the potential for an early starter open pit gold project at West Kalkaroo, which is adjacent to the large Kalkaroo Copper-Gold Project.
Other strong new horizontal clay-hosted, base of Tertiary assay results include:
- 4 metres at 1.20 g/t from 56 metres;
- 4 metres at 3.33 g/t from 56 metres; and
- 1-metre at 1.70 g/t from 57 metres.
Aircore method used
This drilling is being carried out by Havilah’s drilling crew using the aircore drilling method, which is suited to clayey material and soft decomposed rock.
The mineralisation occurs in a near-horizontal layer in Namba Formation clays, near the base of the Tertiary age sediments.
These flat-lying sediments lie unconformably on the ancient metamorphosed bedrock that is the primary source of the gold.
At this location, at the eastern end of the conceptual starter open pit, the base of Tertiary gold-mineralised layer is more than 20 metres deeper than in the west and appears to be following the deepening bedrock surface.
This gold mineralisation is not included in any resource at this stage but is likely to be of economic importance because it occurs in what would normally be considered as waste overburden material that must be removed to access the underlying copper-gold ore body.
Gold in other zones
As is normal Havilah practice, the aircore 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.
Encouraging gold intercepts in these zones include:
- 4 metres at 0.9 g/t from 87 metres (outside current resource);
- 17.5 metres at 0.71 g/t from 76 metres (in saprolite gold zone);
- 11 metres at 2.22 g/t from 81 metres (outside current resource);
- 22 metres at 1.0 g/t from 86 metres (in saprolite gold and native copper zones);
- 25 metres at 2.04 g/t from 80 metres (in saprolite gold zone);
- 14 metres at 1.0 g/t from 87 metres (in saprolite gold zone); and
- 4 metres at 3.77 g/t from 97 metres (in saprolite gold zone).
Area of drilling within the confines of the conceptual starter open pit at West Kalkaroo in relation to the greater Kalkaroo copper-gold deposit
Two of the drill holes extended gold mineralisation southwards beyond the current resource boundary in a formerly under-explored area, which the company considers has good exploration potential.
In every case the drill holes ended in gold mineralisation, suggesting that it may continue at depth.
Conceptual gold-only starter
The intersections outside the current resource envelope are of particular interest as there are very few earlier Havilah holes this far south, and conceptually there is the possibility of significant new mineralisation here coincident with brittle fracturing in an anticlinal fold structure
Dr Giles added: “Once results are finalised for this round of drilling Havilah’s mining engineers will be able to confirm the expected viability of a gold-only starter open pit.”
Shares have been as much as 8% higher to 10.5 cents intra-day.