Australian lithium producer, Pilbara Minerals Limited (Pilbara Minerals - ASX: PLS) is pleased to announce a further substantial increase in the Mineral Resource at its flagship 100%-owned Pilgangoora Lithium-Tantalum Project in WA's Pilbara region to 308.9 million tonnes, reinforcing its position as the world's premier hard rock lithium operation.

JORC 2012 MINERAL RESOURCE UPDATE

The updated JORC 2012 compliant Mineral Resource incorporates all historical data including drilling data acquired through a number of exploration campaigns completed by Pilbara Minerals between November 2014 and June 2021. The update also includes the integration of the former Altura Lithium Operations Mineral Resource. The estimation was carried out by independent resource consultancy, Trepanier Pty Ltd, resulting in the estimation of Measured, Indicated and Inferred Resources. The reporting of all domains (using a cut-off of 0.2% Li2O and depleted to end of June 2021) results in a Measured, Indicated and Inferred Mineral Resource estimate totaling: The envelope was wire-framed using both geological logging information (in particular logging of zoning within the pegmatite) and assay data for Li2O, Ta2O5 and Fe2O3.

GEOLOGYThe Pilgangoora Lithium-Tantalum deposit is located on the western flank of the East Strelley greenstone belt, in a sequence of highly deformed, fault bounded mafic dominated supracrustal rocks, which protrude into the Carlindi Batholith. Lithologies within the project area are dominantly tholeiitic metabasalts with thin interflow metasedimentary units. The metabasalts may contain abundant fine to coarse grained actinolite, possibly of hydrothermal origin, within the centre of the project area is an intrusive sequence of layered meta-ultramafic sills, with subordinate metamafic units, are up to 500m thick. This ultramafic sequence is comprised of peridotite, pyroxenite and Mg- and Fe-rich varieties of dolerite, with gradational contacts between units. Four phases of deformation have been recognised in the project area. The first phase (D1) produced the steeply inclined attitude of the supracrustal rock sequence by the development of a fold and thrust belt. A regional strike slip fault system developed across the greenstone belt in D2, as an interconnected network of layer parallel strike slip faults with discordant cross faults.

This faulting pattern is particularly strongly developed in the vicinity of the Central pegmatite domains. The D3 event is related to the pegmatite emplacement - these breach the D2 structures and have a local preference for exploitation of the Ultramafic rock package.

Three principal pegmatite groups or domains are identified in the centre of the project area - Eastern, Central and South. In addition, there are three outlying pegmatite groups, Lynas Find, Monster and South End. Pegmatites of the three principal domains have a strike length of up to 1.4km, and mostly range in thickness from 1-30 metres, although pegmatites of the Central domains may be up to 70m thick. Drilling has shown that the pegmatites occur as dykes dipping to the east at 20-60-degree, striking parallel to sub-parallel to the dominant NNW trending schistose (D3) fabric within the greenstones. Pegmatites of the three principal pegmatite groups typically breach D2 faults. The Central pegmatites generally occur within dip-slip (D3) shear zones, and the Eastern pegmatites within strike slip (D3) shear zones

Contact:

Ken Brinsden

Tel: +61 (0)8 6266 6266

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