Dundas Minerals Ltd (ASX:DUN) has intersected broad zones of nickel mineralisation during reverse circulation (RC) drilling at Jumbuck Prospect in the highly prospective Albany-Fraser Orogen in Western Australia.
Notably, assays from two drill holes have returned broad intersections of anomalous nickel and chromium including:
- 34 metres at 0.23% nickel, including 6 metres at 0.38% nickel; and
- 33 metres at 0.14% nickel and 0.27% chromium.
In each zone, nickel enrichment starts at the base of complete oxidation and continues through to the underlying Gabbro (mafic intrusive), which hosts the majority of the mineralisation.
Furthermore, elevated Total Rare Earth Oxide (TREO) assay values were also returned from near-surface clays in several drill holes.
“Most encouraging”
Dundas Minerals managing director Shane Volk said: “The results from these two holes, which at 135 metres are still relatively shallow, are most encouraging.
“It is still early days at Jumbuck, however, the nickel enrichment within the Mafic intrusive is significant.
“If you look at a nearby nickel deposit such as Nova (~115 kilometres northeast of Jumbuck), you see that the actual deposit sits well below a similar Mafic intrusive complex, with similarities in geochemistry to what we are seeing in these drill holes."
Jumbuck drilling
The Jumbuck drilling program was designed to test for mineralisation to a maximum depth of 150 metres in the vicinity of a historic rotary air blast (RAB) drill hole, drilled by AustQuest Limited in 2011.
The recent Dundas Minerals holes are within 50 metres of the historic hole and were specifically positioned to test a distinctive 'bulls-eye' magnetic anomaly.
Volk adds: The Jumbuck anomalism remains open both along strike and at depth.
“The next steps for us will be the completion of detailed magnetic inversion models, analysis of district gravity data (including a possible infill gravity survey) and revisiting the SkyTEM electromagnetic data for conductive anomalies.
“The objective of this work is to develop at least one diamond drill hole target to test beneath the near-surface enrichment zones.
"From a diamond drill hole we’d expect to conduct downhole electro-magnetic survey in combination with a surface moving loop electromagnetic survey.
“The objective of the surveys is to identify any conductive responses adjacent to initial drilling, for further drill testing.”
Elevated REEs
Dundas observed elevated rare earth element (REE) values in three drill holes during the analysis of assay results for the Jumbuck drilling program.
Similar elevated REE values were also noted in assay results returned for three drill holes from the company’s Kokoda gold prospect drilling program.
These widespread and unexpected elevated REE values may represent an additional exploration opportunity for the company.
As an initial step to understand the possible REE opportunity, Dundas initiated a review of all historical exploration data from within its Dundas project area for possible anomalous historic REE assay results and is also reviewing the geology in the context of possible REE deposits.
In addition, the company commenced researching what techniques, especially geophysical survey techniques, may be helpful to prioritise areas within the Dundas project area that may host concentrations of REEs.
Discrete magnetic anomaly
Dundas has also identified a series of discreet magnetic anomalies in the northwest section coincidental to Jumbuck
Volk adds: What is also encouraging for Dundas Minerals, is that there are a series of other discrete magnetic anomalies within the northwest section of our Dundas project area that appear not dissimilar to Jumbuck, plus there is a notable gravity high apparent in the district-scale gravity data – which could represent a discrete mafic/ultramafic intrusion.
“Such anomalies may also represent valid nickel exploration targets, which we may be able to progress in parallel with Jumbuck.”