ProjectsWest Australian Lithium
Pilbara Projects – Western Australia
Western Australia is a premium lithium province with high-grade lithium deposits associated with rare metal pegmatites.
Sayona’s Pilbara leases cover some 1806km2 and are centered in the world class Pilgangoora lithium district. The project tenure is shown in the figure below.
The company is exploring for hard rock lithium deposits where lithium is present as the mineral spodumene, hosted in rare metal pegmatites. Besides lithium these pegmatites may be elevated in cesium and tantalum (hence the term LCT pegmatites), and other rare metals.
In the Pilbara, spodumene pegmatites are related to certain parent granites with a specific aluminium and lithium geochemistry. During the crystallization of these granites a hydrous, flux rich magma may separate and migrate into the surrounding country rock. As it continues migrating some of the magma may separate again, leaving the residue progressively enriched in lithium and the other elements which preferentially remain in the magma phase. This process of fractionation may evolve so that a progression of mineral zones may be recognized, reflecting distance from the parent granite. The last formed pegmatite, which is typically the most distant zone from the granite, is the albite-spodumene class of pegmatite.
The Pilbara tenure has seen little or no past exploration for lithium. Sayona’s exploration methodology is to identify fertile source granites, test for marginal rare metal LCT pegmatite systems and then explore these areas for an albite – spodumene zone.
To help define prospectivity within a pegmatite system the company has developed an algorithm based on elements (including tantalum, cesium and others such as beryl, gallium and thallium) that characterize the various stages of fractionation, allowing vectoring into potential areas of spodumene formation.
Within some tenements historical activities, such as alluvial mining which have recovered tantalum and other metals, are indicative of fractionated, rare metal pegmatite systems and has allowed early recognition of prospective target areas.
The Mallina project is the most advanced of the Pilbara portfolio. Multiple zones of newly discovered spodumene pegmatites have been identified within a 25km2 zone. The pegmatites occur in three main swarms; the western Discovery prospect, the central Area C prospect and the Eastern Group pegmatites. Surface sampling has been encouraging with rock results up to 4.6% Li2O returned from spodumene pegmatite at surface. Mapping has confirmed the pegmatites can be extensive, with the Eastern No.2 pegmatite being over 1300m in strike extent and up to 20m in thickness.
Two drill programs of 48 RC drill holes have been completed for total of 3,568m. Selected intercepts are displayed below.
The identification at the Area C prospect of spodumene pegmatite in drilling, from surface and of good intensity (to a maximum 3.18% Li2O), has provided encouraging evidence that the project can host economic grades of lithium mineralisation. The intercept, email@example.com% Li2O, from 0m in drill hole SMRC040, remains open at depth and to the east, south and north, where the pegmatite is masked by thin cover.
At the Eastern No.2 Pegmatite drill results include near surface mineralisation extending to some 50m depth. Structural studies indicate the spodumene pegmatites have a moderate plunge and this extension at depth remains untested. The best result in the area was a down dip drillhole, SMRC042, which was completed to test for grade variations and possible weathering effects, which returned 20m @ 1.12% Li2O from 4m, and 12m @ 0.87% Li2O from 28m.
Further work to test these targets, together with first exploration over the remaining 120km2 tenement area is planned.
The Tabba Tabba project comprises six tenements covering 588km2, located 40km to the north of the Pilgangoora lithium mining area. The main Tabba Tabba tenement, E45/2364, is centered in an area of historic tin and tantalum mining. Spodumene pegmatite has been identified in adjacent tenure and the Tabba Tabba project provides exposure to the area’s emerging lithium prospectivity.
Within E45/2364, where the company has rights to 100% of the pegmatite minerals, exploration has identified three new areas of fractionated rare metal pegmatites, as well as seven soil anomalies of LCT type pegmatite geochemistry. None of the prospect areas has been drilled. Geochemistry and target areas are shown in the figure below.
Exploration on the other Tabba Tabba tenements is more grass roots in style but work has returned pegmatite with anomalous lithium, tantalum and cesium, over which more focused exploration is planned.
Moolyella and other Pilbara project areas
The Moolyella project is located to the east of Marble Bar. The area hosts a number of lithium, tin and tantalum occurrences including the historic Moolyella tin field where explorers have identified spodumene pegmatite associated with the intrusion of the Moolyella monzogranite.
Within the company’s tenure (three tenements covering 334 km2) a number of lithium-cesium-tantalum albite pegmatites and fractionated fertile source granites have been identified. Orientation rock and soil sampling has been undertaken and further exploration, targeting the anomalous areas has returned mica rich pegmatite with up to 1.40% Li2O. Further work is planned for the 2019 field season.
Other project areas, including Cooglegong, Wodgina West are grass roots in nature but each has areas displaying pegmatite fractionation which requires follow up.
Deep Well Project
The Deep Well tenement application covers an area of 119km2 near Port Hedland. It was pegged to secure an area of interpreted granites prospective for lithium pegmatite and has subsequently been considered prospective for the conglomerate hosted style of gold mineralisation.
The tenement has poor exposure of bedrock but areas of Fortescue aged Mt Roe Basalt crop out in the in the western tenement region, margined by younger Mallina Formation sediments. Elsewhere in the Pilbara the contact between these units is prospective for gold mineralisation. At Deep Well the Upper Mallina succession are also a target, comprising basin margin, high energy sediments, close in age to the Central Rand Group, which hosts the majority of the gold in the Witwatersrand.
Geochemical sampling of oxidized pyrite cubes (metamorphosed authigenic pyrite) has returned elevated gold (to 120ppb Au) as well as anomalous bismuth, molybdenum, antimony, nickel, tellurium, uranium and other pathfinder elements. Further work is planned to better understand the area’s geology and mineralisation potential.
Mt Edon Lithium Project
This project, located in the South Murchison covers the southern portion of the Paynes Find greenstone belt. This is host to an extensive swarm of pegmatites. The pegmatites have not previously been assessed for their lithium potential but have been variably prospected and mined for tantalum, feldspar and beryl.
Reconnaissance exploration has identified lepidolite (lithium mica) bearing pegmatite with a peak assay of 1.57% Li2O. Geochemical results indicate that the pegmatite suite becomes increasingly fractionated towards the west and further exploration is planned testing in this area.
Soil Geochemical sampling – Tabba Tabba Project
Pegmatite In Drill Sample – Mallina Project
Mallina Project RC Drilling, Dan O’Neill and Matt Thomas
Geophysical readings – Deep Well Project
Logging Drill Cuttings – Mallina Project
Preparing for RC Drilling, Area C Prospect – Mallina Project
Eastern No.2 Pegmatite Prospect – Mallina Project
Geological Logging – Mallina Project
Marking up Drill Bags – Mallina Project
3.44% Li2O Sample, Spodumene Pegmatite – Mallina Project
Area C Prospect – Mallina Project
Pegmatite Search – Pilbara
Spodumene Pegmatite – Mallina Project