Calidus has a portfolio of lithium projects in Western Australia, held either 100% or via a joint venture vehicle. Details of the projects are shown below.
Pirra Lithium (Calidus 50%)
Pirra Lithium Pty Ltd (Pirra Lithium), is owned equally by Calidus and Haoma Mining NL (Haoma).
Pirra Lithium has been assigned tenements and lithium rights across the most prospective lithium ground in the Calidus and Haoma portfolios. These tenements and lithium rights cover 1,063km2.
Across the Pilbara Craton, including at Wodgina, Pilgangoora, and Global Lithium’s Archer deposit near Marble Bar, lithium is hosted in pegmatites associated with granites of the Split Rock Supersuite. The tenements that Pirra hold target areas adjacent to the Split Rock Supersuite.
Substantial pegmatites have already been mapped on the tenements, several of which are associated with known tin-tantalum fields. Early stage exploration involving stream sampling and mapping is underway in a logical fashion across the greater tenement package.
Spear Hill Project (Pirra Lithium)
Location and Overview
The Spear Hill area, about 50km SW of Marble Bar, is part of the historic Shaw River tin field which was mined for alluvial tin from 1893–1975.
Figure 1 – Location of Spear Hill and tenement holdings and lithium rights of Pirra Lithium. On the RHS, Pirra tenements and lithium rights are shown on a background of GSWA’s 1:500,000 state bedrock geology and linear structures layers.
The Shaw River tin field lies almost entirely within granitic rocks of the Shaw River batholith. The batholith is a composite feature of old (>3,400-million-year-old) granitic gneisses, granites, and slivers of greenstone, intruded by 2,950-million-year-old granites and fractionated 2,890–2,830-million-year-old granites of the Split Rock Supersuite.
Mapping has identified a lithium-bearing pegmatite dyke exposed for about 2.5km along strike, with a second, less well-defined pegmatite about 250m north of the discovery pegmatite. There is also another narrow pegmatite in the footwall to the main pegmatite adjacent to the Hillside–Marble Bar Road.
Rock-chip sampling along the strike extent of the main pegmatite has yielded grades of up to 2.75% Li2O. The parallel pegmatite to the north returned assays up to 1.67% Li2O.
Figure 2 – Geology map showing the distribution of the lithium pegmatites identified at Spear Hill to date. Also shown are the Li2O values for all the samples recently collected and analysed, and results released previously.
About 1.7km to the southwest of the original discovery, three more poorly exposed lithium-pegmatites and areas of muscovite and lepidolite alteration were identified over nearly 1.8km of strike length on E45/4587.
A recent drill programme intersected lithium pegmatites up to 250m down dip. The best intercepts included:
- 2m @ 1.11% Li2O from 19m in 22PIRC026,
- 2m @ 1.09% Li2O from 5m in 22PIRC020,
- 2m @ 1.03% Li2O from 25m in 22PIRC031,
- 3m @ 0.95% Li2O from 4m in 22PIRC021, and
- 4m @ 0.74% Li2O from 20m in 22PIRC025.
Figure 2 – Mapped distribution of the lithium pegmatite at Spear Hill and the location of the 20 RC holes drilled. Also shown is the location of the cross section in Figure 3.
Figure 3 – Representative cross section of the mineralised pegmatite at Spear Hill.
Northampton Lithium Project – Calidus 100%
Calidus has pegged two tenements directly in the Northampton region of WA that are prospective for lithium. The two tenements, north and southeast of the town of Northampton, are in the Northampton Inlier, which represents the exposed part of a Mesoproterozoic terrain comprising granitic and metasedimentary gneisses intruded by Mesoproterozoic to Neoproterozoic granites and pegmatites. The inlier possesses some striking similarities with the Gascoyne Province, in terms of both rock types (muscovite-and tourmaline-bearing pegmatites, high-grade gneisses) and the age of the last cratonisation event (~1,000 Ma). The Gascoyne Province is currently the focus of intense exploration for lithium and rare-earth element ore bodies. The area under application contains some pegmatites mined for mica, analogous to those near lithium prospects in the Gascoyne Province.
Figure 4 – Map showing the location of two applied tenements in the Northampton area and GSWA’s 500k geology layers. Rock units not shown in the legend consist of younger sedimentary rocks of the Perth Basin.