Alto Metals Ltd (ASX:AME) has received further encouraging drill results from the Sandstone Gold Project in Western Australia, showing broad, high-grade mineralisation across multiple deposits.
Exceptional Bull Oak hits
The Bull Oak deposit, in particular, returned ‘exceptional’ intersections highlighted by 212 metres at 1.2 g/t gold from 28 metres, including 1 metre at 116 g/t, which ended in mineralisation.
Alto managing director and CEO Matthew Bowles said: “Bull Oak has already delivered some impressive results and SRC1027 intercepting multiple high-grade quartz reefs, within an overall 212-metre intercept, including 1 metre running 116 g/t gold at the interpreted Kohinoor North Reef, is the best result Alto has had here to date.”
This standout result suggests continuity of mineralisation across multiple high-grade quartz reefs within a broader mineralised system, extending beyond the current resource.
Another drill hole, some 90 metres southwest, intersected 48 metres at 0.6 g/t gold from 83 metres depth, ending in mineralisation and peaking at 9.6 g/t over one metre.
These results point to considerable expansion potential and the presence of stacked mineralised lodes within the granodiorite host rock.
High-grade reef at Vanguard
At Vanguard North deposit, the company drilled an 80-metre step-out hole and intersected a high-grade reef that extends beyond the known limits of the deposit.
Results from Vanguard North included 6 metres at 1.9 g/t gold from 148 metres, including 1 metre at 10.4 g/t gold.
Further exploration in a new area, 500 metres along strike, targeted a ‘lookalike’ quartz reef, which returned 1 metre at 3.9 g/t gold from 115 metres.
Additionally, extensional drilling at the Ladybird deposit, 5 kilometres north of Vanguard, uncovered further high-grade zones, including 9 metres at 2.2 g/t gold from 70 metres, with a peak interval of 10.6 g/t gold over one metre.
Alto’s ongoing RC drilling campaign, amounting to 3,440 metres across 28 holes, aims to test extensions and continuity at these deposits and explore new mineralised zones.
Sandstone Project’s Bull Oak resource currently sits at 1.9 million tonnes at 1.1 g/t gold for an estimated 65,000 ounces of gold, with potential growth highlighted by this latest round of assays.
The project's exploration target, announced in June 2024, should expand the resource, with estimates suggesting up to 8.8 million tonnes at 1.3 g/t gold for a potential 295,000 ounces of gold.
“These latest results from below the shallow mined Bull Oak open pit have confirmed the continuity of broad zones of gold mineralisation over 500 metres of strike, outside the resource, and represents the opportunity to considerably increase the scale of the deposit,” Bowles said.
Work is ongoing
“It is also exciting to see step-out drilling at Vanguard North has intersected the high-grade reef, outside the resource, 80 metres down plunge, returning +10 g/t and first pass drilling at a ‘look-a-like target’ 500 metres along trend has successfully intersected the quartz reef confirming the targeting model.
“Further work is now being undertaken for follow-up drilling at these prospects.”
Metallurgical test-work at Bull Oak has demonstrated high recovery rates of more than 90% from cyanide leaching, reinforcing the deposit's economic viability.
Further metallurgical studies are planned to support ongoing development at Sandstone.