Blesberg Lithium-Tantalum Project – South Africa
AVL has commenced the staged acquisition of a controlling 50.03% interest in the Blesberg Lithium-Tantalum Project and has completed the acquisition of a 100% interest in South African Lithium Pty Ltd.
The Blesberg Project is located approximately 80km north of Springbok in the remote Northern Cape Province of South Africa (see below). It lies at the western end of the Northern Cape Pegmatite Belt.
The deposit is one of the largest known economically mineralised and exploited pegmatite deposits in the Pegmatite Belt.
Mining at Blesberg commenced in 1925 when it was worked mainly for bismuth. The main products from later mining were beryl, bismuth, tantalite-columbite, spodumene, feldspar and mica. Feldspar production from the mine was reported to be of very high quality with the feldspar being pure white and unstained by iron oxide. Production was sold into the glass and ceramics industry.
Historical information about mine production quantities and quality is very limited, however a sample analysis of a 150 ton shipment of feldspar from the 1960’s assayed 1.74% Li2O (Schutte, I. Memoir 60 Geological Survey of South Africa,1972).
The main pegmatite at the Blesberg Mine is referred to as Noumas I and is the site of the most extensive historical excavation and includes underground stoping. The Noumas I pegmatite is hosted in granodiorite country rock and is a heterogeneous lithium-caesium-tantalum (LCT) type pegmatite. Heterogeneous pegmatites consist of zones that vary in mineralogy and texture. The internal zonation of the Noumas I pegmatite is summarised in Table 1 below (Minnaar and Theart 2006).
Table 1. Summary of the Zonation of Noumas I Pegmatite.
An initial site visit was completed by personnel from MSA Group (Pty) Ltd (“MSA”) as part of the due diligence process undertaken by SA Lithium. A total of 20 samples were taken from 9 sample sites considered representative locations of spodumene mineralisation observed in the Spodumene Zone within the old mine workings.
Sampling was not intended to provide a representative Li-grade of the pegmatite or the Spodumene Zone but rather an indication of the lithium content of the spodumene.
Most of the spodumene observed and sampled in the open pit was either altered or replaced and, consequently, contained very low remnant Li2O grades. However, six of the spodumene samples reported lithium contents of between 1.27% – 6.42% Li2O indicating that unaltered spodumene is present (see Plate 2). Importantly these high-grade samples were not restricted to any specific portion of the Spodumene Zone.
Sample location W0113 (6.42% Li2O)
Table 2 – Sampling Results (Rock chip samples)
The assay results confirm that where the spodumene has been extensively altered, depletion in lithium due to late stage hydrothermal processes has occurred. This is a common situation in many pegmatite deposits including the prolific Pilbara pegmatites of Western Australia and others located in very old geological terranes.
It is likely the depletion is restricted to the upper portions of the pegmatite with the potential for fresher, unaltered lithium-bearing material at depth within the Spodumene Zone. This implies significant potential for the unexposed component of Blesberg below the current shallow workings, along strike to the west under cover, and in the adjacent pegmatite bodies within the Blesberg Prospecting Right area.
In the last quarter of 2016 AVL appointed an experienced international field geologist residing in Cape Town to manage the exploration activities at the Blesberg Mine. During this quarter encouraging preliminary ground surveys identified 500m strike of outcropping pegmatite running WNW from the Blesberg Hill workings, and a soil orientation program was completed (results pending). Based on recommendations made by MSA the Company commenced a reverse circulation and diamond drilling programme at Blesberg in the first quarter of 2017 and a local drilling contractor was awarded the tender. Other activities to be undertaken in 2017 will include:
Mapping and sampling of additional pegmatite zones across the Prospecting Right area;
Evaluation of all potential economic minerals present at Blesberg, including feldspar, tantalum, beryl, caesium and lithium potential;
Determination of an accurate exploration target at Blesberg (including the main Noumas I pegmatite and adjacent pegmatite bodies), and
Volumetric and analytical assessment of the current dump and ramp material at Blesberg.
With so much potential, AVL looks forward to reporting progress on these exploration activities as they are completed.