Astro Resources NL (ASX:ARO) has intersected "significant" intervals of lithium prospective Siebert Formation claystone in its maiden drill program at Polaris Project in Nevada, marking a “successful start” to the company’s expanded North American lithium exploration strategy.
Of the four aircore holes drilled to date, three have intersected the regionally significant lithium-bearing host rocks and all of these holes ended in the Siebert Formation, indicating further potential for clays beyond the depth of current drilling.
Key intersections to date in the campaign are:
- PL01 intersected 68.6 metres of Siebert Formation from 128 metres to the end-of-hole;
- PL04 intersected 27.4 metres of Siebert Formation from 129.5 metres to the end-of-hole; and
- PL02 intersected 4.6 metres of Siebert Formation from 150.9 metres to the end-of-hole.
As the Siebert formation is known to host large lithium deposits, it presents as a compelling exploration target in Astro’s hunt for lithium mineralisation and represents the basis and key technical target for the current drilling campaign.
Regionally important claystone rocks
Astro executive chairman Tony Leibowitz said: “This is a very pleasing start to our first lithium drilling campaign in Nevada.
“Despite some challenging drilling conditions, which the team has done a great job in overcoming, the first few holes have intersected the regionally important claystone host rocks for lithium that the technical team set out to find.
“This shows that we have all the right ingredients to start work to define a significant lithium resource in Nevada.
“This marks a successful start to our expanded lithium exploration strategy in North America, and we are looking forward to reporting further results from this exciting program in the weeks ahead.”
What is Siebert Formation?
The Miocene-aged Siebert Formation, the local name for the Ts3 sedimentary rocks mapped across Nevada, is composed of tuffaceous, fine-grained, calcareous lacustrine (lake) sediments.
Notably, this is the main prospective host rock of lithium claystone deposits in the district.
Felsic tuffs are thought to be the principal source of lithium mineralisation in the Siebert, as lithium is hosted in the volcanic glass within the tuffs, which readily weathers to clay minerals.
The Siebert Formation is known to host two of the largest lithium resources in the United States – the 15.8 million tonnes LCE American Battery Technology Corporation’s Tonopah Flats deposit and American Lithium Corporation’s 9.79 million tonnes LCE TLC Lithium Project.
Drill campaign
Astro’s maiden aircore campaign kicked off in late April at Polaris, where four holes have been drilled to date.
A highlight is the intersection from drill-hole PL01 which fielded 68.6 metres of Siebert Formation, dominated by greenish claystone and ended in the formation.
The Polaris program follows hot on the heels of significant exploration campaigns undertaken by other explorers in the region.
The significant level of exploration activity, and the positive results being reported by other explorers in the vicinity, is a testament to the highly prospective nature of the region and, by extension, the inherent potential of Astro’s Polaris and Altair projects.
Chip trays of 5-foot intervals of Siebert Formation claystones intersected in hole PL01 from 425-645 feet.
Forward plan
The drill rig has now mobilised to the Altair project planned hole AL01, south of the Polaris project.
One batch of samples from the drilling campaign has been despatched to ALS Laboratories in Reno for analysis.
Subsequently, assay results are expected for the initial batch approximately in six weeks.