Focus Minerals (ASX: FML) has announced a highly positive update from the staged diamond drilling at Beasley Creek South (BCS) within its Laverton gold project in WA.
The company reported that the diamond drilling at BCS carried out between September and December 2019 has delivered high-grade results.
Significant intersections from the campaign include 4.0m @ 21.69g/t Au from 28m (86.75 GxM); 5.1m @ 14.57g/t Au from 64.9m (74.33 GxM); 7.7m @ 9.16g/t Au from 79m (70.51 GxM); 13.3m @ 4.81g/t Au from 51m (63.94 GxM); and 10.1m @ 6.20g/t Au from 45.9m (62.61 GxM).
The company said that from September 2019, a targeted program of twin infill and extension HQ3 drilling was implemented to accurately determine the resource at BCS.
The company said that the results from the diamond campaign were outstanding, with infill diamond holes upgrading previously low metal parts of the orebody.
FML noted that more than 200m strike in the core of BCS is now reporting very strong mineralisation and consistent widths. The location of the mineralisation is also consistently aligned with the logged position of the Beasley Sheer Zone (Beasley SZ) and hanging wall structures.
The company reported that the BCS deposit has not previously been mined and now has confirmed high-grade oxide mineralisation extending from near-surface to at least 130m depth and open along strike.
FML said that due to the downgrade of previous RC work, the 400m of strike between BCS and Beasley Creek is now considered effectively untested. The Company said that it has begun the follow-up diamond drilling campaign at BCS.
Laverton gold project
The Laverton Gold Project is located on the Laverton Greenstone Belt (LGB) in the Yilgarn Craton of Western Australia. The LGB is believed to be more than 2,500m years old.
The LGB hosts other gold mines including Granny Smith, Sunrise Dam, and Wallaby. Gold production from the belt is estimated to be in excess of 28moz.
Beasley Creek South (BCS)
The Beasley Creek South (BCS) is located along strike and 400m south of the Beasley Creek Deposit. Both deposits are located 10km north-west of the Laverton township.
Beasley Creek was mined by WMC in the late 1980s and the early 1990s, with ore processed at Windarra. Historical production from the 750m N-S striking Beasley Creep OP was 88.8Koz @ 2.42g/t Au.
Drilling by Focus in 2018 and 2019 had delivered a significant new OP oxide resource at Beasley Creek to 180m below surface. This includes
Indicated Resource of 2.02 Mt @ 2.41 g/t Au for 156,500 contained ounces; Inferred Resource of 0.64 Mt @ 1.71 g/t Au for 35,400 contained ounces; and a Total Resource of 2.66 Mt @ 2.24 g/t Au for 191,900 contained ounces.
Beasley Shear Zone
Mineralisation at both Beasley Creek and BCS is located on the N-S trending, moderately east dipping Beasley Shear Zone (SZ).
In 2018, Focus identified that the Beasley SZ was offset 140m to the west by the cross-cutting, SSE dipping Fitton FZ.
This development opened up the southern 400m strike between BCS and Beasley Creek with most drilling located too far to the east. The far south extension of the Beasley SZ is interpreted to merge with the Chatterbox SZ.
Historical RC drilling invalidated
The company reported that 308 holes were drilled into BCS up until the end of 2018, of which only three included diamond core.
In 2018, Focus attempted a small-scale RC program at BCS to target extension of high-grade/high metal content shoots at about 100m depth. However, this had to be abandoned because of the excessive water and very poor sample recovery.
The Focus geology team then determined by a process of targeted twinning/sampling system review that historic reverse circulation (RC) sampling of BCS had been ineffective.
This was because none of the air drill (RC) twins could be replicated by HQ3, with major discrepancies confirmed in grade-by-width (GxM) values. The difference in the results confirmed that RC drilling at BCS suffered from unacceptably high levels of sample loss and downhole contamination.
Examples of recent Diamond HQ3 twins compared to historic RC results include WMC RC Hole – BCP0537 intersected 40m @ 1.43g/t Au from 35m (57.2 GxM) while Focus HQ3 Twin Hole – 19BSDD0063 intersected 19m @ 3.32g/t Au from 31m (59.76 GxM).
This clearly indicated wholesale downhole contamination of samples in WMC hole BCP0537.
Redrilling of resource using HQ3
In September 2019, given the lack of confidence in historic RC at BCS, Focus decided to redrill the resource using HQ3 only.
The company said that the results of 40m x 40m infill HQ3 drilling have been outstanding. Each hole completed into regions previously considered to have limited mineralisation has returned strong results that warrant additional follow-up. Furthermore, the scale, grade and consistency of the deposit is being improved with minable widths of high-grade mineralisation extended to 130m depth.
The company said that the shallow BCS OP exploration target to 130m depth comprises 0.60Mt to 3.29Mt at 2.36g/t to 3.1g/t Au for 60,000 ounces to 250,000 ounces.
Overall more than 20 RC holes were twinned by HQ3 and the RC results removed from Focus Minerals’ drill database.
The company reported that the best five intersections from the campaign included 19BSDD058 – 4.0m @ 21.69g/t Au from 28m (86.75 GxM); 19BSDD080 – 5.1m @ 14.57g/t Au from 64.9m (74.33 GxM); 19BSDD045 – 7.7m @ 9.16g/t Au from 79m (70.51 GxM); 19BSDD072 – 13.3m @ 4.81g/t Au from 51m (63.94 GxM); and 19BSDD073 – 10.1m @ 6.20g/t Au from 45.9m (62.61 GxM)
As a result, the entire strike of Beasley Creek through to BCS is now considered untested. The company said that the strike extension will be followed up in 2020.
Updates and next steps
Focus Minerals said that it anticipates additional drilling to follow up on encouraging results in Laverton.
The company reported that drilling recommenced in January at BCS. FML said that an updated resource is due to completed at BCS in the first half of 2020.
Focus Minerals’ CEO, Zhaoya Wang, said: “The results achieved from the diamond drilling carried out late last year were outstanding. Our focus now is to prioritise resource drilling of this exciting new target to deliver a maiden mineral resource at BCS this year, which could potentially strengthen Laverton’s Stage 1 production portfolio.”