Barton Gold (ASX: BGD) (OTCQB: BGDFF) has expedited a follow-up drilling campaign at the high-grade Tolmer silver prospect within its Tarcoola project in South Australia.
The 4,000-metre reverse circulation program is targeting extensions of high-grade assays from previous drilling that exceeded 2,000 gram-metres silver.
It will infill the high-grade zone on a different orientation to test continuity and a new interpretation of local geological controls, as well as potential extensions of mineralisation along a newly-inferred strike.
Managing director Alexander Scanlon said the emerging silver portfolio remained a significant contributor to the company’s regional strategy that features accelerated exploration at Tolmer and resource upgrade programs at the nearby Tunkillia project.
Modern Silver Discovery
Tolmer is one of Australia’s highest-grade modern silver discoveries, identified in a maiden hole which yielded a peak intersection of 6m at 4,747 grams per tonne silver plus 4m at 13.2g/t gold.
Multiple rounds of follow-up drilling have since identified a continuous footprint of silver-dominant mineralisation where shallow horizons host peak grades of 17,600g/t silver and 51.2g/t gold less than 50m from surface.
In August, Barton completed three diamond holes to investigate local geological controls and improve on the follow-up drilling.
This work identified both an ‘upper horizon’ of broad, shallow silver mineralisation that is largely independent of gold and appears open to the west, and a second ‘lower horizon’ at the interpreted boundary of oxide and fresh zones hosting silver and gold in broad intervals.
Best assays were 4m at 1,417g/t silver from 9m including 1m at 3,790g/t, 14m at 434g/t silver from 46m including 1m at 3,530g/t from 54m, 3m at 3.25g/t gold from 54m including 1m at 7.5g/t, and 3m at 993g/t silver from 55m including 2m at 1,475g/t.
‘Western Zone’ Extensions
Barton has also recently received soil assays from Tolmer indicating potential extensions of the main ‘western silver zone’ and new, previously unrecognised gold-silver-lead targets.
Lead and silver assays indicate mineralisation extending approximately 200m west and 100m east of current drilling.
Mineralisation from Tolmer’s 2025 discovery hole has been concentrated to prepare material for petrology utilising scanning electron microscopy, which will assist in designing a full metallurgical program.
This test has produced a concentrate grading more than 100,000g/t (~10%) silver from a simple gravity process, which could have potential implications for low-cost, high-margin operations if it remains consistent for the mineralisation.
In parallel with drilling, preliminary metallurgical studies to understand the petrology and paragenesis of the Tolmer silver mineralisation are ongoing.
Full metallurgical test work using samples from current drilling will follow to determine the origins and formation of the Tolmer mineralisation, and to evaluate the optimal routes for silver-gold processing and recovery.
