Kangaroo Island project – South Australia

Summary

Lithium Australia NL (‘LIT’) holds a granted exploration licence (‘EL’) and two exploration licence applications (‘ELA’) on Kangaroo Island (see Figure 1). The Dudley and Vivonne projects are the result of LIT’s strategy to continue its Australia-wide search for strong domestic lithium holdings to add to its portfolio of projects.

Figure 1: Kangaroo Island project.

Geology

Regional radiometric surveys show that both project areas are underlain by zones of elevated potassium anomalism, which have been interpreted as being an indication of buried granitic rocks and associated pegmatite intrusions (see Figure 2).

Figure 2, showing zones of elevated potassium anomalism.

The Dudley applications (ELA2017/00005 and ELA2017/00236) lie on the eastern side of Kangaroo Island, 100 kilometres (‘km’) south-southwest of Adelaide, and have a combined area of 90 km2.

At Dudley, the focus is the pegmatite intrusives into the Tapanappa Formation. The pegmatites form dykes and sills of predominately feldspar-quartz-muscovite, with varying amounts of topaz, tourmaline, graphite, citrine, and apatite. They are extensive, with up to a 5 km strike length presenting as discontinuous, partially buried exposures. Although there is mention of lepidolite in a report by the Geological Survey of South Australia, there has been no modern exploration for lithium minerals in the area.

The applications contain the Dudley Mine, which operated during the early 1900s and 1980s. Gem tourmaline, ceramic-grade feldspar, silica, and kaolin for brickmaking were mined.

LIT’s granted EL, Vivonne (EL5960), lies on the western side of Kangaroo Island, some 160 km southwest of Adelaide, and covers 44 km2. The underlying geology, which is similar to that of the Dudley ground, consists of intrusive pegmatites in the Tapanappa Formation. These are more pod- to stock-like than dykes and sills. No modern exploration of these pegmatites is recorded.

Proposed exploration

LIT will commence desktop studies and assemble a database from open-file government and company reports. On grant, LIT will secure access and commence a programme of mapping and sampling of outcropping pegmatites. The surface geology will guide the planning of soil geochemical surveys designed to map the distribution of any additional pegmatite bodies obscured under shallow cover.

The outcomes of this exploration will provide LIT with a better understanding of the two areas’ potential to host lithium mineralisation and help define areas warranting further investigation by drilling.