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Three Rivers Project Overview
The Three Rivers Project lies some 120km north of Meekatharra in the Peak Hill Mineral Field of the Southern Gascoyne district. Gold exploration within the district has been ongoing for over 150 years, though the area encompassing Alchemy’s Three Rivers Project has only received exploration attention for gold since 1988.
Geology
The tenure at Three Rivers covers the southwest contact between the Marymia Inlier and the Bryah - Padbury Basin. The Marymia Inlier is a fragment of northeasterly trending Archaean granite - greenstone basement exposed at the junction of the Proterozoic Bryah - Padbury, Yerrida and Bangemall Basins. In the vicinity of the project area, the Marymia Inlier abuts the Peak Hill Schist, which is exposed as a dome or anticline and constitutes a tectonic unit representing the southwestern tip of the Marymia Inlier. Rocks of the Peak Hill Schist include quartz-sericite schist, quartz-muscovite schist and quartz-muscovite-biotite-chlorite schist, which have been variously deformed and contain a range of mylonitic textures and discrete mylonitic units. Rocks of the Bryah-Padbury Basin exposed in the project area are mainly Bryah Group Karalundi Formation sandstone and the Naracoota Formation volcanics consisting of metabasalt and mafic-ultramafic schist with local interflow sedimentary layers. The Naracoota Formation overlies and locally interfingers with the Karalundi Formation. Iron formation, ferruginous shale and siltstone of the Robinson Range Formation, exposed along the northern margin of the Robinson Syncline, occupies the southern parts of the tenement area. The southern contact of the Marymia Inlier and Peak Hill Schist with the Bryah Group is currently interpreted to be a thrust fault with the rocks of the inlier overthrusting the Bryah domain. Bangemall Group sediments cover the Marymia Inlier along its northern boundary and may occur in the northern extremity of the tenement area. The stratigraphy is cut by numerous east to east-north-east trending dolerite dykes. Metamorphic grade ranges from upper amphibolite to granulite facies. 
Mineralisation
The Peak Hill Mylonite, which forms as part of the Peak Hill Schist, is spatially associated with gold mineralisation in the Peak Hill and Mount Pleasant deposits. Gold mineralisation also occurs in or adjacent the contacts between the Bryah Group’s Karalundi Formation sandstone and the Naracoota Formation volcanics (e.g. Wilgeena and Jubilee deposits), and between the Naracoota Formation volcanics and the overlying Padbury Group Ravelstone Formation (e.g. Harmony deposit).
The iron ore prospectivity is limited to the deeply weathered banded iron formations of the Robinson Range Formation in the project’s southern parts.