In its bid to define a significant lithium deposit in WA’s Pilbara region, Raiden Resources (ASX:RDN) is following in the footsteps of another explorer that has made a successful play for the metal in the same territory – Azure Minerals – with the added curiosity of both companies having previously focused on copper and nickel discoveries.
Indeed, based on exploration work at its Andover North and Andover South projects, Raiden might be described as what Azure was only a year ago.
Raiden’s exploration licenses are located immediately adjacent to Azure’s Andover deposit and located within the Mafic-Ultramafic Intrusive Complex of the same name.
Exploring for copper-nickel deposits at the Andover Complex seemed obvious, given that it shares geological features with both the East Kimberley region – which hosts Panoramic Resources’ Savannah mine – and the Fraser Range province, home to IGO’s Nova-Bollinger: both rich in nickel, copper and cobalt.
But what’s the deal with lithium there?
If we’re talking about Azure, it has identified a multiplicity of pegmatites across three target areas at Andover, and is progressing exploration with eight diamond drill rigs, having already drilled 340 holes for a total of around 101 thousand metres, with approximately only 40 percent of the pegmatite targets tested to date.
A maiden mineral resource estimate is expected in the second quarter of 2024, with the figure predicted to be between 100 and 240 million tonnes, comprising 1 to 1.5 percent lithium oxide (Li2O). A scoping study should be progressed by the fourth quarter.
Raiden too is progressing its exploration along nicely: this month announcing two heritage surveys for its project, due to start on March 25 (at Andover South) and April 2 (at Andover North).
The surveys were conducted with support of the Ngarluma Traditional Owners to ensure that areas of cultural significance will not be disturbed.
The company plans to follow up its heritage surveys with air core drilling at Andover North, with an objective of defining further targets on Andover North, followed by drilling – both diamond and RC (reverse circulation) – across both holdings once this is completed.
Following the path from nickel to lithium prospecting
Managing director Dusko Ljubojevic said the success of Azure Minerals at Andover had provided a guide for Raiden’s own exploration program.
“We have used their exploration campaign as a template for our own progress to date, which has been very successful and the mineralisation on our pegmatites seems to be associated with the same system,” he said.
“We closely monitor their drilling strategy and orientations in order to align it with our own field observations and plans.”
But even before that, Azure’s unveiling of significant lithium mineralisation at its play on the Andover Complex had helped Raiden shape its focus to lithium from nickel in the same area.
“Our initial application for the Roebourne project was for nickel, but after the lithium discovery by Azure, we have refocused on that metal and we have expanded our ground holding,” Mr Ljubojevic said.
“The lithium mineralisation at Andover North and South is associated Spodumene, which is the premium product.
“We are also inspired by the size and width of the Azure pegmatites, plus the fact that fact that the infrastructure for development is about as it good as it gets.”
Predictions for pegmatite mineralisation
Raiden used interpretation of datasets for the Andover Complex – both recent and historical, including geophysics – to guide its exploration program, building on the expectation of high prospectivity for pegmatites, which have already been defined on the southern permits, but also on its Andover North project in, where shallow sediment cover obscures potential pegmatites.
For example, the presence of a consistent magnetic signature among the rocks underlying Andover North shows the Andover Complex to be much larger than previously mapped, according to Raiden.
Andover South is considered highly prospective, where outcropping pegmatites have already been mapped over a 4.2-kilometre strike length and individual pegmatite dykes defined up to 50-metre widths.
In October, X-ray diffraction was confirmed that Spodumene is the dominant lithium mineral at Andover South, which is also the case at Azures world class discovery.
Raiden believes that dual tracking a parallel exploration campaign over the Andover South and North projects may lead to further definition of potential pegmatite mineralisation.
Driving ahead with other Pilbara projects
While Andover’s history and mineralisation certainly draw much attention to Raiden’s exploration work, its other projects in the Pilbara are also producing impressive results.
In an announcement to the ASX on March 22, Raiden highlighted two discoveries at its Mt Sholl project across two metals: lithium and nickel.
In both the north-central and south-eastern parts of the Mt Sholl tenements, two lithium anomalies were identified through infill soil sampling, these having a peak soil value of 188 ppm lithium (405 ppm lithium oxide, or Li2O).
At the same time, Raiden released results of exploration done by Quantum Minerals Australia – with whom the company signed a memorandum of understanding (MOU) in December – showing a new nickel (in soil) anomaly in the northern part of Mt Sholl, recording values up to 1,770 parts per million (ppm) nickel, present across a strike length of up to 1.2 kilometres.