Alto Metals Ltd (ASX:AME) has confirmed the geological models for the Vanguard and Tiger Moth prospects within its wider Sandstone Gold Project in Western Australia.
A reverse circulation (RC) drilling program consisting of two holes recovered high-grade intercepts from each prospect, as well as providing samples for further metallurgical test work.
A number of assay results from aircore (AC) drilling completed in May and June were also received, indicating additional mineralisation across three other prospects.
The drill hole at Vanguard intersected 40 metres at 3.5 g/t gold from 60 metres, including 12 metres at 5 g/t from 60 metres, while Tiger Moth hole intersected 8 metres at 4.1 g/t from 52 metres.
Preliminary test work conducted by Alto demonstrated recoveries of more than 92% gold from both oxide and primary gold zones.
READ: Alto Metals reveals maiden gold resource at Indomitable and Vanguard camp deposits
Alto managing director Dermot Ryan said: “Alto’s recently published [JORC 2012] mineral resource estimate for the Indomitable and Vanguard camps was the result of applying a systematic exploration approach.
“This process resulted in the selection and successful testing of a number of litho-structural gold targets.
“The next stage is to step-out and drill test the down-dip/down-plunge extensions of these newly discovered mineralised structures and convert gold mineralisation into mineral resource.”
READ: Alto Metals extends laterite gold mineralisation at Indomitable North with high-grade assays
The RC program initially consisted of four holes but two that were drilled at the Indomitable prospect were abandoned prior to reaching the mineralised interval due to difficult drilling conditions.
Samples for preliminary metallurgical test work from Indomitable were thus obtained from RC cuttings from a hole drilled in February.
Results from test work to date indicate robust recovery processes, however, Alto has planned further work to optimise recoveries.
Sandstone geology plan showing Alto prospects and landholdings
READ: Alto Metals defines shallow high-grade gold at Tiger Moth deposit
AC drill holes at Vanguard have identified gold mineralised drill intercepts away from the main Vanguard and Vanguard North deposits.
Known mineralisation at the Sandstone North prospect, which extends over 300 metres of strike, was confirmed to be open to both the north and south from 13 AC assays drilled along the flanks of the prospect.
Angled AC holes drilled adjacent to the northern edge of the Bulchina open pit in June confirmed that mineralisation exists outside of the pit.
Further drilling is planned at all three of the prospects in the coming year.
READ: Alto Metals extends large gold-in-soil anomaly at Hancocks prospect
Alto plans to conduct RC and diamond core drilling at Vanguard and Indomitable to define the extent of the mineralised structures, as well as AC drill testing of soil and laterite gold geochemical anomalies.
The company will also progress its resource evaluation work, which will include:
Maiden mineral resource estimation for Ladybird, Havilah and Sandstone North using existing available data;
Update to the company’s JORC 2012 mineral resource inventory; and
Geotechnical drilling, bulk density measurements and metallurgical test work where required to convert gold mineralisation into mineral resource.
READ: Alto Metals defines Valiant gold anomaly at Sandstone project
Alto holds about 800 square kilometres of prospective ground in the Archaean Sandstone Goldfield in the East Murchison mineral field of WA.
Since acquiring the project in 2016, the company has compiled and reviewed a large legacy database ahead of a series of focused exploration and drilling campaigns.
Alto’s goal is the delineation of a plus-1 million-ounce JORC mineral resource that could become the basis for the re-establishment of standalone oxide and primary gold mining and milling operations.