The high grade nature of Great Boulder Resources’ high priority Mulga Bill prospect continues to shine bright, with new assays hitting grades in excess of 30 grams to the tonne.

A major discovery at Great Boulder Resource’s (ASX:GBR) Side Well project in WA’s fertile Mid West gold region, assays from six holes in an eight hole diamond program at Mulga Bill are now in and the results are stellar.

In line with previous high grade intersections, highlights from the sampling include:

  • 2.0m at 9.41g/t Au from 90m including 0.56m at 30.80g/t Au in 22MBDD004
  • 0.57m at 19.20g/t Au from 11.75m in 22MBDD004
  • 1.52m at 5.93g/t Au from 148.6m in 22MBDD004
  • 0.43m at 11.53g/t Au from 106.21m including 0.15m at 30.50g/t Au in 22MBDD003; and,
  • 0.33m at 24.70g/t Au from 153.52m in 22MBDD003

Those results are no outliers. Last year’s discovery hole at Mulga Bill intersected 3m at 34.5g/t from 32m, with multiple intersections of extremely high grade gold vein positions found in the surrounding area since.

“I am very pleased to note that the high-grade gold intersected in diamond holes 22MBDD003 and 22MBDD004 are consistent with our geological interpretation, which also means we are becoming increasingly confident in our understanding of the high-grade northern area of Mulga Bill,” Great Boulder managing director Andrew Paterson says.


Great Boulder (ASX:GBR)
New high grade hits in the northern area of Mulga Bill. Pic: Supplied (Great Boulder Resources)


A new approach

A deep diamond hole from the recent program consisting of a 250m deep RC hole with a 200m diamond tail into a gravity and electromagnetic target on the other hand did not pull up significant gold intersections.

The geophysical anomalies could be explained by high sulphur values, but promisingly significant pathfinder elements were uncovered, indicating the area is sitting next to potential gold mineralisation.

Further analysis of the recent 3D-IP data has shown a zone of increased resistivity immediately east of the anomaly tested by hole 21MBRCD096.

Previous drilling to the north suggests the position on the eastern edge of the chargeable zone is highly prospective for gold mineralisation, and the interface between chargeable and resistive features may represent a lithological contact, a place where rock types meet which is often fertile for gold mineralisation.

The hunt continues

“Further south at the large geophysical target we are seeing evidence of cross-cutting structures which may explain the lack of continuity there, as seen in 21MBRCD096,” Paterson says.

“We are now looking slightly further east of the IP target at that northing, where the team drilled six AC holes in the area last week to test the hypothesis that gold mineralisation is offset to the east.

“We learn something from every hole we drill. I am very keen to see the next round of assays come back from the lab and also very excited to start RC drilling targets at the southern end of the Mulga Bill – Loaded Dog corridor,” he continues.

“Along with the remaining 2 diamond holes, we now have 31 RC holes and 57 AC holes at the assay lab so we’re expecting a steady flow of results over the next two months. The field team is now drilling an AC program at Whiteheads, and we will be back at Side Well for the next RC program at the end of the month.”


Great Boulder (ASX:GBR)
Side Well is located in a multi-million ounce gold field alongside Westgold’s Meekatharra project. Pic: Great Boulder

What’s next?

Contractors Challenge Drilling are expected to return to Side Well at the end of June to start RC drilling, keeping the rig onsite for the remainder of the year.

Their first priorities will include RC testing of the southern end of the Mulga Bill corridor, where an aircore hole struck 3m at 8.56g/t at the bottom of the shallow hole including 1m at a massive 23.78g/t in its final metre.

The area remains completely untested by RC drilling but is of a similar tenor to mineralisation in the aforementioned discovery hole.



This article was developed in collaboration with Great Boulder Resources, a Stockhead advertiser at the time of publishing.


This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.