Great Boulder Resources (ASX: GBR) has intersected high-grade gold in the “gap” zone between the Central and HGV resource areas in Phase 3 RC drilling at the company’s flagship Side Well Gold Project near Meekatharra in Western Australia.
The Phase 3 program was designed to test the gap between our Central and HGZ zones at Mulga Bill. This is outside the current mineral resource, so we’re excited to see high grades confirming our structural interpretation in that area,” Managing Director, Andrew Paterson, said.
“These high-grade intersections are interpreted to include mineralisation in subvertical lodes as well as high-grade west-dipping veins at depth, which remain open down dip and along strike.
“The RC rig is now completing a small Phase 4 programme, which is filling in a few gaps in the data prior to our next resource update.
“We are also looking forward to starting a new heritage survey over the Ironbark corridor next week. This is an important step forward for Great Boulder, setting the stage for a big regional AC drilling campaign to test this extremely prospective zone in the months ahead.”
17 RC holes were drilled for a total of 3,870m in this campaign, with resource definition drilling ongoing at Mulga Bill in preparation for the pending Side Well resource update. The main aim of this program was to test the continuity of mineralisation in the gap between the Central and HGV Zones at Mulga Bill. Until recently this area been relatively poorly tested because many of the earlier holes were drilled towards the west. With improved geological understanding, all subsequent holes have been drilled towards grid east to intersect west-dipping vein structures.
Drilling within the gap has intersected mineralisation within subvertical shear-hosted or “Malvern” lodes as well as west-dipping vein hosted “Cervelo” lodes. This combination of structures is the same as that seen within the mineral resource areas to the north and south. By extrapolation, we expect that the same orientations are likely to control mineralisation at Mulga Bill North.
Within the gap area the strike of the shear appears to flex from northwest to northeast, forming a dilational jog. Tensional high-grade vein sets dipping shallowly to the west have also been intersected, and the result in 23MBRC045 (6m @ 30.96g/t Au from 113m including 1m @ 173.50g/t Au) is likely to be within one of these veins.
Hole 23MBRC057 (2m @ 13.50g/t Au from 188m and 8m @ 5.71g/t Au from 216m) is interpreted to represent an intersection between the deeper west-dipping Cervelo lodes and the north-south shear style mineralisation. The Cervelo lodes have now been intersected over a strike length of more than 300m, and mineralisation remains open down dip and along strike.
The latest drill results have provided significant high-grade results outside the existing resource estimate, now proving continuity of mineralisation over a total strike length of 1,100m.
Next Steps
RC drilling is on track to be completed this week. With gold and multi-element assay turnaround currently averaging approximately three weeks, all data should be received by the first week of October.
While the drilling and assay data is being collated Great Boulder’s geologists will start updating the mineralisation envelopes for Mulga Bill and finalise those for Ironbark.
All data and wireframes are on track to be delivered to the resource estimation consultant in mid- October with the aim of re-estimating both mineral resources by the end of October.
