ASX-listed junior explorer Great Southern Mining has defined several large kilometre scale gold anomalies within its Duketon tenements from regional soil sampling and will be drill testing at the Amy Clarke prospect by the end of the year. A geophysical magnetic low channel associated with the gold anomalies can be traced 3 kilometres north to Regis Resources’ 322,000-ounce Erlistoun deposit that grading at 1.9 grams per tonne gold.
The Duketon gold project is about 45km north of Laverton in WA’s north-eastern Goldfields and encompasses more than 450 square kilometres within the gold-bearing Duketon greenstone belt.
A 649 sample multi-element soil sampling program was carried out over two months earlier this year which covered a substantial 4.3km by 900 metres wide area over the Amy Clarke prospect. Samples were sent to the lab for gold determinations and 21 samples returned gold values higher than 25 parts per billion and six sites showed gold values more than 100 parts per billion, with the highest value going a respectable 690 parts per billion.
Soil samples were additionally assayed for 48 other elements to aid in targeting and to identify any “pathfinder” elements associated with gold anomalies. Interestingly, arsenic, tungsten and bismuth all showed excellent correlation with gold, with concentrations increasing towards the centre of the ‘hotspots’. The company says the gold association with the “pathfinder” elements indicate the source of the anomalies is less likely to be transported as they are less mobile within the weathering regime and will not have been transported far from source.
Intriguingly Amy Clarke is in an area only ever sparsely RAB drilled to a maximum of just 9m depth way back in 1996. Great Southern says it is remarkable the area has seen so little exploration, with zero drilling since the shallow RAB drilling by Sons of Gwalia in the 1990’s where the end of one line of shallow RAB drilling drilled a portion of the anomaly. That hole recorded a gold value of 3m at 340 parts per billion. A review of the historical drill logs indicates the vertical RAB hole ended in mineralisation within a 2m quartz vein. According to management, this geologically significant gold intersection further confirms the validity of the target.
The position of the soil anomalies is of particular interest as they are located in a long geophysical magnetic low feature, with distinct magnetic high features on each side which correlate to conspicuous outcropping ridges of banded iron formation.
This geophysical magnetic low channel can be traced 3km north to the nearby Erlistoun gold deposit and is interpreted to be the same granodiorite rock which host the Regis Resources’ 322,000 ounce Erlistoun deposit. Limited granodiorite outcrops occur in the area validating this interpretation according to the company.
Great Southern has also interpreted two cross-cutting north-eastern geophysical structures as possible fluid traps which could have aided in localising the mineralisation. The structures have a close spatial relationship to the gold in soil anomalies and this pattern is seen at the neighbouring Erlistoun gold deposit and other large gold deposits in the Duketon Belt.
The Duketon Belt is home to multiple million-ounce Archean orogenic gold deposits where gold is found in quartz veins that crosscut intrusive host rocks. In 2008, Regis Resources discovered the Garden Well 2.1-million-ounce deposit grading 1.4 g/t gold following on from a small scale aircore program targeting soil in lag anomalies which were a similar size to Great Southern’s Amy Clarke gold-in-soil anomaly.
The company is wasting no time and has a 10,000m air core drilling program ready to go over Amy Clarke with all approvals in place and a drill rig secured. Results are expected by the end of this year.
Great Southern is on a roll now with further assay results expected next week from its reverse circulation drilling at the promising Southern Star prospect. Spectacular Southern Star intersections have so far included a broad 59m interval tipping the scales at 2.1 g/t gold from 53m that contained higher-grade cores of 9m at 4.5 g/t and 16m at 3.2 g/t.
Any more of them and it will be off to the races for Great Southern followers.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
By Matt Birney
