Targeting lithium mineralisation in the Taupo Volcanic Zone, New Zealand

摘要

Lithium is a major component in advanced batteries and is therefore a critical element to the green technologies sector. Because of the predicted increase in future demand for Li, the need to understand the overall potential for Li mineralisation in New Zealand has come to the forefront. Consequently, a New Zealand-wide mineral potential model was generated by GNS Science and New Zealand Petroleum and Minerals at 100 m resolution (Turnbull et al, 2018). The model combines two mineral systems for Li deposition: Li-Cs-Ta pegmatites associated with peraluminous granitoids, and hydrothermally altered rhyolitic lacustrine sediment-hosted deposits. In the Taupo Volcanic Zone (TVZ) efforts are underway for extracting Li directly from an active hydrothermal system, and commercial interest is also shown in the hydrothermally altered, lithium-rich sediments. In the TVZ, where the Li is exclusively associated with hydrothermal activity, the model highlights areas that have increased potential for economic Li, with most targets clustering in the lake district of Rotorua (Figure 1). The nation-wide Li potential model indicates widely distributed and elevated Li prospectivity, as the caldera is an ideal location for sediment-hosted Li in hydrothermally altered rhyolitic lacustrine deposits.