Terra Metals strikes high-grade silver and tungsten at Onslow project

Partial assay results from a maiden diamond core drilling campaign at the Onslow project in Western Australia have returned high-grade silver and tungsten for critical minerals junior Terra Metals (ASX: TM1).

The company intercepted a geological zone that assayed 6 metres at 179 grams per tonne of silver from 160m, with a high-grade zone of 1m at 1060g/t silver, 0.23% copper and 0.99% tungsten.

It sits within an interpreted high-sulphidation epithermal alteration zone extending from approximately 158m to 184m.

Deeper potential source

Epithermal alteration is commonly associated with high-grade silver mineralisation and could potentially be linked to a deeper mineralised porphyry source.

A zone from 134m to 158m sits immediately above the high-grade silver result and was logged to have zones of disseminated, vein, foliation and fracture-controlled sulphides.

Summit said the mineralisation style was “unexpected” as the target was originally iron-oxide-copper-gold (IOCG) mineralisation.

It is planning petrology work to further characterise the geological zone and mineral deportment.

Untested anomaly

The new zone sits on the edge of an untested electromagnetic (EM) anomaly defined during an airborne survey conducted by Terra in 2022.

The anomaly sits to the south-east of the interpreted high-sulphidation epithermal silver mineralisation.

It is characterised as being a conductive body measuring approximately 600m long and 120m thick and will be re-analysed following results from the diamond program.

Summit will also review the core to confirm if silver-sulphide minerals, including argentite and acanthite (both of which are associated with epithermal systems), are also present.

Maiden result

Chief executive officer Thomas Line was pleased with the maiden results.

“Intercepting high-grade silver mineralisation is a great result for first-pass reconnaissance drilling in a frontier province,” he said.

“We are now reviewing available datasets to determine a model for high-sulphidation epithermal silver mineralisation and the possibility of a porphyry source.”

Dante drilling

Earlier this month, Terra completed a 60-hole maiden reverse circulation campaign for a total of 10,220m across four targets at the flagship Dante copper-gold-platinum group element (PGE) project in WA.

Drill results from the first three holes (of a total of 13) at the Crius Reef prospect confirmed the presence of high-grade magmatic sulphides including copper, gold and PGE.

The best results were 5m at 0.56% copper, 0.53g/t PGE3, 0.61% vanadium oxide and 18.5% titanium dioxide from 80m, including 2m at 0.83% copper, 0.52% vanadium oxide and 16.6% titanium dioxide.

New reefs

Results from the first five holes at Cronus Reef confirmed the presence of extensive magmatic copper, gold and palladium sulphide mineralisation from near-surface.

The maiden work also included additional mapping and ground-truthing at Dante that identified the new Typhon, Helios and Pytho reefs.

These three new outcrops increase the total strike length of Dante reefs by 80% to 42 kilometres and are all in proximity to the existing Crius, Hyperion, Oceanus and Cronus reefs.