Macarthur has 15 Exploration Licenses in the Pilbara covering a total area of approximately 1,300km².

In May and June 2016, Macarthur completed two heliborne reconnaissance field trips across a portion of its tenements in the Pilbara region. Sampling across several pegmatites yielded encouraging results warranting further exploration. The best lithium results are from a swarm of pegmatites within Exploration Licence application 45/4702 exploited in the past for tin and tantalum. A sample of lithium muscovite from one old working returned 0.2% Li₂O and elevated tantalum and tin values confirming the rare element character of this pegmatite. A feldspar-quartz-muscovite pegmatite within Exploration Licence 45/4711 also returned 111 parts per million (“ppm”) lithium (“Li”).

In addition to the reconnaissance sampling, historical results of the Geological Society of WA (“GSWA”) include the Tambourah North lithium pegmatite located in Exploration Licence application 45/4848. A rock sample collected by Fortescue Metals Group Ltd in 2012 on the western edge of Exploration Licence application 45/4702 returned a result of 876 ppm Li (0.19% Li₂O).