Metal Bank identifies large-scale porphyry system at 8 Mile gold project
A large-scale mineralised hydrothermal system estimated at over 10km wide has been identified.
Initial reconnaissance sampling at Metal Bank’s (ASX: MBK) 8 Mile gold project in south-east Queensland has identified a large-scale mineralised hydrothermal system containing two gold targets with preliminary technical indicators which point to a potentially-prolific discovery.
Located 15 kilometres northeast of the 2 million ounce Mt Rawdon gold mine (owned by Evolution Mining ASX: EVN), the priority Eastern and Western targets are believed to flank the potassic/magnetite alteration of a large-scale hydrothermal mineral system, currently estimated to be 10km wide.
Both targets are associated with broad zones of magnetite destructive alteration (forming magnetic lows) which is a typical feature of intrusion-related gold deposits.
Historical drilling
The Eastern target represents a gold porphyry system where a drilling program in the mid-1990s intersected broad gold mineralisation associated with the Flori’s Finds and Painkiller prospects, located 1.5km apart.
Completed in 1994, the program comprised 10 holes to a depth of just 60 metres, with no follow-up activities conducted after the assay results.
Highlights from drilling at Flori’s Finds include 10m at 0.35 grams per tonne gold from 26m; 22m at 0.7g/t gold from surface; and 26m at 0.52g/t gold from 6m.
Historic results from Painkiller include 38m at 0.46g/t gold from 14m, and 24m at 0.34g/t gold from 6m.
“The mineralisation intersected by historical drilling is associated with an intense alteration zone (sericite-pyrite) approximately 1km wide,” the company said.
“[It is] coincident with a magnetic low approximately 6.5km long, representing the interpreted extent of the Eastern target.”
Large-scale breccia system
Initial reconnaissance exploration over the Western target has identified a large hydrothermal breccia system on a similar scale to some of the largest breccia-hosted gold deposits in Queensland.
The system is believed to contain two distinct phases of mineralisation – an early hot “core” phase, and a later superimposed intrusive phase.
The 8 Mile project is interpreted to represent the upper portions of an intrusion-related gold system similar to that encountered in many of Queensland’s larger gold deposits such as Kidston (3.7Moz), Mt Leyshon (3.5Moz), Ravenswood (3Moz), Mt Rawdon (2Moz) and Mt Wright (1.3Moz).
Eastern priority
Metal Bank managing director Tony Schrek said the company’s activities will focus on the Eastern target as an immediate priority, with validation of historical sampling and detailed geological mapping planned before ahead of further drilling of the gold porphyry system along strike and depth.
Detailed mapping, soil sampling and IP geophysics have also been planned for the Western target area prior to drill testing.
“The Eastern target is where our immediate exploration activities will be focused due to the highly-encouraging, broad, low-grade gold intersected during the historical shallow drilling program,” he said.
Earlier this year, Metal Bank generated near-surface gold grading 69.8g/t at the Advance target within its Triumph gold project, also in Queensland.
At midday, shares in Metal Bank were trading 16.67% higher at $0.014.