Dart Mining NL (ASX:DTM) is buoyed by assay results from deep diamond drilling of geophysical targets at the Granite Flat Copper-Gold Project in northeast Victoria which demonstrate broad intervals of gold mineralisation, coincident with intervals of copper, silver and molybdenum.
“These encouraging drill results demonstrate that the company’s identified geophysical targets are associated with long intercepts of gold, copper, and silver mineralisation," DTM chairman James Chirnside said.
"This further underscores the significant bulk tonnage potential of Dart’s Granite Flat Copper-Gold project.”
The company drilled more than 1,000 metres across three holes targeting geophysical anomalies.
Assay highlights include:
EMDDH006 -
- 113 metres at 0.24 g/t gold, 0.11% copper and 0.75 g/t silver from 28 metres including 47 metres at 0.33 g/t gold, 0.16% copper and 1.0 g/t silver;
- 165 metres at 92 ppm molybdenum from 151 metres including 25 metres at 330 ppm molybdenum; and
- 409 metres at 0.11 g/t gold and 0.0 5% copper from 23 metres (entire hole, no cut-off).
- 42 metres at 0.26 g/t gold from 5 metres including 5 metres at 1.12 g/t gold 0.6 g/t silver and & 0.12% copper.
- 143 metres at 0.18 g/t gold from 12 metres, including 25 metres at 0.49 g/t gold; and
- 291 metres at 0.11 g/t gold from 12 metres (entire hole, no cut-off).
Drilling highlights from diamond drill holes EMDDH006, EMDDH007, & EMDDH008. Note that no cut-offs are applied for internal dilution factors.
Positive results
Looking at each hole specifically, Hole EMDDH006 was designed to target a substantial induced polarisation (IP) geophysical anomaly identified in late 2021. At 432.06 metres depth, this hole represents the deepest hole to date in the Granite Flat project.
Throughout the length of this hole, several intervals of potassic- and phyllic-altered quartz-feldspar porphyry and monzodiorite were identified, which are broadly associated with low-grade copper-gold and molybdenum mineralisation.
The copper and molybdenum grade distribution in EMDDH006 displays a notable correspondence with the IP anomaly targeted, whereby gold mineralisation is associated with a low chargeability zone immediately above the high chargeability anomaly targeted.
EMDDH007 targeted a second significant IP anomaly, 1.3 kilometres away on the southern side of the Granite Flat project and was drilled to a depth of 267.32 metres.
This hole encountered narrower zones of gold, silver and copper mineralisation, in part associated with narrow structures and basaltic dykes carrying disseminated pyrite and chalcopyrite, with semi-massive sulphide mineralisation near the margins.
Diamond hole EMDDH008 was drilled to a depth of 303 metres and targeted a sheeted vein system situated above a zone of elevated resistivity.
Whilst not a strong low chargeability anomaly, the assay results from EMDDH008 display a similar pattern to the previous two holes, whereby zones of diminished chargeability are associated with long intercepts of low-grade gold mineralisation.
Examples of mineralisation styles encountered in the recent drill holes completed at Granite Flat.
What’s next
Based on these results, Dart’s preliminary interpretation is that zones of moderate to strong resistivity may reflect areas of stronger silicification favourable to gold mineralisation and potentially to stronger chalcopyrite mineralisation (chalcopyrite is not a chargeable sulphide species).
The company now intends to test the strong resistivity anomalies located between the strong chargeability anomalies.
Dart has been encouraged by the gold results, which demonstrate strong, low-grade gold mineralisation over long intervals in holes separated by up to 1.5 kilometres. This further demonstrates that the mineralising system at Granite Flat is of significant size, corroborated by the exceptional soil results.
The company will now turn its attention to advancing the project with the next stage of drilling targeting both the recently announced geochemical anomalies and the IP resistivity anomalies.
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