Roe Gold Project
The 1.7Moz Roe Gold Project is located between two operating gold mines 100km east of Kalgoorlie, Western Australia, on a recently identified southern extension of the 22Moz Laverton Tectonic Zone.
After discovery of the Bombora deposit below thin transported cover in 2015, over 300,000m of RC and diamond drilling has revealed a typical Archean, multi-lode gold deposit hosted by dolerite with some of the best drill hits in Western Australia, such as 17m @ 15.85g/t, 7m @ 61.78g/t and 32m @ 15.31g/t (July 2020). The project has the attributes of scale, high grade and outstanding growth potential in a 9km-long gold system that is growing along strike and at depth.
Gold at the main Bombora deposit occurs in a 150m-wide zone, starting 5m from surface in a 3km-long single pit configuration.
The discovery of high grade lodes at scale below the open pit Resource in the last year is game-changing, indicating scope to transition from open pit to underground mining in the future, significantly enhancing operational flexibility and longevity.
Geology
Breaker’s initial discovery at Bombora in 2015 is now 3.7km long and part of a rare 9km-long greenfields gold district with the noteworthy attributes of scale, grade and huge growth potential. This, and the project’s proximity to two operating gold mines with processing facilities, make it a highly desirable asset in an industry facing declining resources.
Gold at Bombora mainly occurs where sulphide-impregnated “lodes” (mineralised faults) intersect the upper, iron-rich part of a thick dolerite, the dominant style of gold mineralisation in Western Australia. Bombora is directly comparable geologically with the Golden Mile, St Ives and Paddington deposits in WA. These deposits typically extend to great depth.
Gold lodes form mainly where these faults intersect the iron-rich part of the dolerite
- Steep lodes = south plunge.
- Flat/West lodes = north plunge.
#ASX Release 07/08/2017, ^ASX Release 20/03/2018, @ ASX Release 31/07/2018, ^^ ASX Release 30/05/2017
Resource
Gold starts 5m from surface and occurs in multiple lodes over a 150m-wide zone over a 3.7km strike length with a gold endowment of 4-5,000oz per vertical metre. An open pit at least 3km long appears likely.
Drilling below and along strike from the 3.7km-long Bombora deposit continues to show predictable and continuous high grade gold over large distances.
A Resource update from the December 2021 quarter followed an April 2021 Resource update by Optiro Pty Ltd, which expanded the Resource by 40% to 1.37Moz, including maiden estimates at the Crescent-Kopai and Claypan deposits, and a maiden underground estimate.
Shallow Open Pit Growth
The open-pit resource is still growing. The Bombora deposit is now 3.7km long after recent drilling added a further 250m of shallow extension at Bombora South (September 2021).
The west-dipping Quarries fault which hosts the gold at Bombora South can now be traced over a 3.5km distance extending from Bombora South into the partially drilled Carbineer area to the northeast.
1.2Moz Bombora Deposit: Part of a Growing 9km Gold System
ASX Release 29/04/2021
In the last year, it has become obvious that the three lode orientations at Bombora are part of a regular network of kilometric-scale faults with good predictability extending over 9km. This understanding is important as it predicts continuity, which we are seeing, and it de-risks future mining.
This opens up the gold potential in several new areas, including along the syenite contact 600m to the east of Bombora, into which the gold-bearing structures at Bombora can now be confidently traced.
Underground Growth
Transformational high grade lodes discovered at scale below the 3.7km-long open pit Resource in the last year are showing the makings of a substantial underground mining proposition that builds on the large open pit resource already defined.
1.2Moz Bombora: High grade at surface, high grade at depth
ASX Release 11/10/2021
The high grade Northern flat lode array below the northern part of Bombora is over 2.2km and is open to the north.
High grade Flat Lode Array – 2.2km and growing
ASX Release 09/03/2021
High grade gold on the Tura steep lode now extends 900m down-plunge and is still growing to the south.
1.2Moz Bombora: High grade at surface, high grade at depth
ASX Release 11/10/2021