Geology

Geology

In this section

The deposit is located in the north Murchison granite-greenstone terrain of the Archean Yilgarn Craton, and is hosted within mafic, ultramafic, extrusive and volcaniclastic rocks of the Gabanintha formation. The mineralisation is hosted in a layered gabbro and closely associated with a series of massive to disseminated V-Ti-Fe bands ranging in size from a few metres up to 20–30 m thick.

geology 1

The project contains 5.5 km strike length of the mineralised gabbro. The iron within the gabbro provides a magnetic signature enabling the “mapping” of the unit (see magnetics image above). The mineralised gabbro generally outcrops as low ironstone ridges within the project area.

A typical cross-section through the Gabanintha deposit is shown below shows the basal “massive” magnetite zone which is overlain by a series of lower grade disseminated bands.

geology

The long section below shows the weathering profile over the northern portion of the Gabanintha deposit. The weathering profile varies with the base of complete oxidation (BOCO) and the top of fresh (TOFR) being shallower in the north (left hand side).

left

The weathering of the basal massive unit has a direct impact on the recoveries of vanadium. The vanadium at Gabanintha is associated with magnetite which is magnetic, hence the first step in processing is magnetic separation. Oxidised magnetite is weakly to non-magnetic and cannot be separated from the gangue minerals (silica, alumina for example) efficiently. Areas where the transition and fresh zones are close to surface have less of this troublesome material and are obvious targets for initial production.