The Emily Ann and Maggie Hays nickel deposits are situated 117 km west of the town of Norseman, Western Australia, within the Lake Johnston Greenstone Belt.

It was discovered by prospecting in the 1970s by Anaconda Co. and Union Miniere, who had first located a nickel geochemical anomaly and drilled the disseminated halo, but missed the lucrative high-grade massive sulfide mineralisation by as little as three metres.

The recognition of the Maggie Hays orebody by LionOre geologists in the late 1990s was based upon electromagnetic geophysical surveys and deep diamond drilling of conductive anomalies.

The general stratigraphy of the belt is, from base upwards, a thick sequence of felsic orthogneiss composed of fragmental to glomerocrystic feldspar gneiss, known as the footwall felsic sequence; the ultramafic units of komatiite affinity, "overlain" by grunerite-magnetite-quartz-amphibole banded iron formation of the Honman Formation, tholeiitic basalt and metasedimentary rocks.

[3] The Maggie Hays orebody sits upon the upper surface of an overturned sequence of komatiitic ultramafic cumulates dipping west at between 65 and 75 degrees.

The ultramafic body is in the form of a "keel", with a southward plunging folded surface pinching out the northern end of the resource, where it enters a heterogeneously sheared structure.

The internal structure of the ultamafic includes some interesting features, notably a so-called "chill-zone" of assumed orthocumulate composition, which occupies the marginal facies of the ultramafic unit.

This is in turn overlain by stringy-beef textured recrystallised disseminated ore zones containing retrogressed metamorphic olivine and distinctive bladed anthophyllite.

The Emily Ann orebody is a folded and highly mylonitised shear-hosted nickel sulfide and ultramafic unit, in the form of an open overturned synclinal structure plunging shallowly north-east.

At its simplest, magmatic nickel sulfides are not usually found displaced so far into the footwall as at Emily Ann, where the material has moved up to 600m off the basal contact of the ultramafic unit.