Whundo Cu-Zn

The Whundo Project is located approximately 40 km south-southwest of Karratha in the West Pilbara Region of Western Australia and is approximately 12.5 km southeast of the Radio Hill nickel plant (Figure 1).

Regional Geology

The known copper and zinc deposits at Whundo are confined to a single stratigraphic horizon as a series of NW to NNW plunging shoots that outcropped as a sinuous line of discontinuous goethite- hematite gossans that can be traced for some 500 metres along strike. Individual ore shoots have a restricted strike length and are commonly 1-5 metres thick but reach a maximum thickness of 20 metres in the hinge zone of two small upright synclines in the axis of the major synclinal structure where they form the Whundo deposits.

The stratigraphic sequence at Whundo has undergone upper greenschist to lower amphibolite grade metamorphism, and is overprinted, in part, by hornblende hornfels contact metamorphism. These units have been folded about a moderately north plunging (25°-45°) synformal structure.

The West Whundo deposit outcropped as a gossan folded around a synclinal nose. The gossan was about 135 metres in length and up to 10 metres wide in the core of the syncline which plunges shallowly to the north. The gossan was surrounded by chloritic and sericitic schists, and with volcanic rocks present in the sequence.

Secondary copper mineralisation at West Whundo is present in two zones within the syncline; a southern zone centred about 75 metres  to the north of the gossan, and a northern zone centred a further 90 metres  to the NNE. The southern zone has a diameter of about 60 metres  and the northern about 30 metres.

Figure 1: West Pilbara regional geology (Source GSWA 1:500,000 digital geological map with units modified to simplify legend. MGA94 Zone 50 coordinates)

2022 Drilling Program

In early 2022, GreenTech undertook a maiden 4,974m RC drill program at Whundo and Ayshia to test multiple drill-ready targets aimed at growing the existing JORC 2012 compliant resources at Whundo, as well as lateral and deeper extensions to the eastern and western lobes of the Whundo resource.

At Whundo, the Company drilled 25 holes for 3,838m, with significant intersections returning:

  • 32m @ 2.43% Cu from 75mincluding 17m @ 4.37% Cu and 0.46% Zn from 90m, including 7m @ 7.83% Cu0.64% Zn and 0.26g/t Au from 95m in RC0051
  • 62m @ 1.12% Cu1.36% Zn and 0.36g/t Au, including 19m @ 1.6% Cu, 2.27% Zn and 0.51g/t Au from 21m in RC0071
  • 45m @ 1.15% Cu and 2.6% Zn from 23m, including 12m @ 9.17% Zn2.34% Cu and 0.62g/t Au from 52m in hole 22GTRC0081
  • 8m @ 2.65% Cu, 0.64% Zn and 0.11g/t Au from 141m in hole 22GTRC017
  • 10m @ 2.85% Cu and 0.96% Zn from 162m in hole 22GTRC023

2023 Drilling Program

Greentech followed up the 2022 drill program with successful drilling in early 2023. This allowed the Company to identify new mineralised events at the Austin and Yannery prospects and to increase its mineral resource estimate (MRE). The assay results from this drilling included the following intercepts;

Austin

Hole 23GTRC001

  • 19m @ 0.81% Cu from 225m, including:
  • 7m @ 1.87% Cu from 226m
  • 1m @ 5.4% Cu from 226m

Elevated zinc, gold and cobalt were also intercepted, including:

  • 9m @ 0.285% Zn from 226m
  • 2m @ 1.35g/t Au from 178m
  • 15m @ 0.04% Co from 226m, including 6m @ 0.073% Co from 226m

Yannery

Hole 23GTRC009

  • 21m @ 2.1% Cu from 22m, including
  • 8m @ 5.2% Cu from 31m, and
  • 3m @ 13.1% Cu from 32m, and
  • 1m @ 23.1% Cu, 37.1g/t Ag from 34m, and
  • 6m @ 0.3g/t Au, 7.7g/t Ag from 31m

Hole 23GTRC011

  • 10m @ 3.22% Cu from 21m, including
  • 7m @ 4.45% Cu, 0.15g/t Au, 2.8g/t Ag from 24m, and
  • 3m @ 9.5% Cu, 0.19g/t Au, 3.5g/t Ag from 28m

Hole 23GTRC006

  • 50m @ 0.4% Cu from 10m, including
  • 8m @ 0.2g/t Au from 13m, and
  • 8m @ 0.27g/t Au from 25m, and
  • 5m @ 1.2% Cu from 40m

Hole 23GTRC009C

  • 30m @ 0.37% Cu from 1m, including
  • 6m @ 1.1% Cu from 4m

Hole 23GTRC002

  • 21m @ 0.51% Cu from surface, including
  • 7m @ 1% Cu from surface, and
  • 6m @ 0.8g/t Au from14m

Figure 2: Whundo Project Area showing VTEM anomaly outlines from late-time VTEM data.

Combined Whundo Project Resources

The combined Whundo and Ayshia resources are shown in Table 1 below (refer ASX announcement dated 12 April 2023 for full details).

Table 1: Combined Whundo and Ayshia JORC 2012 Mineral Resource Estimate

Ore Type Grade Range category Tonnes (kt) Cu (%) Zn (%) Cu Metal (t) Zn Metal (t) Total

Metal

(t)

Whundo >0.25 Indicated 4,271 1.05 0.90 44,755 38,334 83,089
  >0.25 Inferred 0.854 1.39 0.45 11,876 3,811 15,685
Ayshia >0.5 Inferred 0.916 1.3 2.3 11,908 21,068 32,976
             
Total >0.5 Ind & Inf 6,041 1.14 1.05 68,539 63,213 131,752

*Whundo deposit resource reported in 2018 using LME metal prices Cu US$6,058/t, Zn US$2,457/t and using 0.5% CuEq cut-off grade

**Ayshia deposit resource reported using LME metal prices for 6/5/2022; Cu US$9,428/t, Zn US$3,828/t, Au US$1,833/oz, Ag US$22.38/oz and using a 0.5% CuEq cut-off grade

Figure 3: Whundo project on mag image

Austin Target

The Austin conductor target was identified from a DHEM survey completed on recent drill hole 22GTRC024 located at the northern margin of the Whundo East Lobe. The conductor lies less than 100m north and down dip of the current Whundo JORC resource and potentially represents a discrete mineralising event. Drill hole 22GTRC024 reported 2m @ 1.5% Cu from 209m within a broader mineralised zone of 12m @ 0.26% Cu from 209m and was interpreted to be peripheral to the DHEM conductor. Hole 22GTRC033 was drilled to test a 6,000 -10,000 siemens conductor identified from a previous DHEM survey completed on nearby hole 22GTRC024. The recently received assay results showed that hole 22GTRC033 intersected a mineralised zone reporting 6m @ 0.6% Cu from 216m. The follow-up DHEM survey of hole 22GTRC033 showed that there was not only a mid-channel in-hole conductor associated with the intersected mineralised zone, but also a strong late channel off-hole conductor of size (~17000-30000S) immediately northwest of this hole.

This new strong conductor which is three times the strength of the previously reported conductor is interpreted as a down dip extension to the mineralised zone intersected in holes 22GTRC024 and 22GTRC033 and will be followed up in the next drill program. This significant mineralised zone representing Austin is located down dip and beneath the main Whundo mineralised zone and appears to be a discrete mineralising event rather than a peripheral extension to Whundo and as such could have an associated thicker, higher-grade core as is seen at Whundo.

Figure 4: Austin section

Yannery Target

The Yannery prospect, located only ~800m from the main Whundo pits and 700m from Ayshia, was mined historically during the period 1920 -1968. There are records of intermittent production during this period of 1132 tonnes of copper ore averaging 21% Cu, and 1911.8 tonnes of cupreous ore averaging 12.87% Cu having been mined from the oxidised and supergene zone1. Underground workings comprising an adit and numerous shafts are present which are limited to the near surface oxidised portion of the prospect.

Past Exploration Activity

Exploration by Fox Resources Ltd in 2006 identified a mineralised zone within the Yannery prospect but peripheral to the historically mined area. This previous work by Fox included RC drilling for a total of nine holes and a fixed loop electro-magnetic (FLEM) survey. The Fox drill sample assay results included:

Hole YNRC004 – 10m @ 2.05% Cu from 40m, including 3m @ 6.10% Cu

Hole YNRC005 – 1m @ 3.16% Cu from 43m

Hole YNRC007 – 10m @ 3.5% Cu from 39m, including 4m @ 8.3% from 41m2

Artemis Resources Ltd also undertook reconnaissance drilling to the NW of Yannery in 2018 aimed at testing for a down plunge extension to the mineralisation reported by Fox. One hole proved successful with the following results reported:

Hole AWRC077 – 18m @ 0.9% Cu from 53m, including 1.3% Cu from 54m

During February 2023 the Company completed a 729m drilling program comprising 15 RC holes was conducted. Many of the holes were terminated prematurely at shallow depths due to intersecting underground workings of which the locations were not accurately known. This program was exploratory in nature and aimed to expand upon previous drilling results reported by Fox Resources in 2006 and Artemis in 2018. The drilling also aimed to investigate the extent and tenor of the copper lodes that were historically selectively mined. DHEM (down hole electromagnetic) surveys were conducted on three of the drill holes after completion of the drill program.

Figure 5: Yannery Target