OceanaGold Corporation has provided an update on exploration and resource conversion drilling at the company’s Haile Gold Mine in South Carolina, USA. This update reports drill results from Haile Underground targets following the updates last provided on 31 March 2020 and 27 February 2019.
The company continues to intercept high-grade mineralisation at multiple underground drill targets with significant drill intersections. At the Horseshoe Extension, of the 13 drill holes completed from the 2021 programme, highlights include:
- DDH1096: 7.45 g/t gold (Au) over 43.4 m from 338.6 m.
- DDH1101: 4.09 g/t Au over 24.7 m from 284.4 m.
- DDH1102: 5.49 g/t Au over 13.4 m from 404 m.
Infill drilling at Palomino continues to improve confidence in grade distribution and continuity of mineralisation. Of the 16 drill holes completed from the 2021 programme, highlights include:
- DDH115: 7.77 g/t Au over 101.3 m from 399.2 m.
- DDH1108: 5.91 g/t Au over 67.1 m from 328.1 m.
- DDH1103: 6.39 g/t Au over 51.5 m from 263.3 m.
Scott Sullivan, Acting President and CEO of OceanaGold, said: “We have always seen the underground potential at Haile, and these drill results highlight the future opportunities that exist for the operation. The Horseshoe deposit will be mined first, with the Palomino deposit being the next target for advancement. We have significant potential at both deposits as reflected by the drill results we are reporting today. We look forward to going underground to not only mine higher-grade ore from Horseshoe, but drill test the multiple targets we have identified.”
The company commenced underground exploration in 2016, shortly after acquiring the asset. Since then, the company has defined a pipeline of opportunities including Horseshoe, Palomino, Horseshoe Extension, and Pisces, all of which are now in various stages of understanding from probable reserves (Horseshoe), inferred resources (Palomino), resource definition (Horseshoe Extension), and initial drilling (Pisces).
Horseshoe Underground Mine
Horseshoe Underground is scheduled to begin development in 2022 with a probable mineral reserve of 3.4 million t at 3.78 g/t Au for 420 000 oz released in the 2020 end of year resource and reserve statement on 31 March, 2021. With an undiluted indicated resource of 3.3 million t at 4.95 g/t Au for 530 000 oz, inclusive of reserves, and an inferred resource of 2.1 million t at 4.4 g/t Au for 300 000 oz, significant potential remains to convert the inferred resources through drilling from underground once the underground development is in place.
Palomino inferred resource conversion
Palomino is located approximately 800 m SW of Horseshoe Reserve, 600 m from the Horseshoe Extension target and approximately 300 m below surface. After Horseshoe, it is the next most advanced underground target with an inferred resource reported on 31 March 2020 of 6.5 million t at 2.8 g/t Au for 600 000 oz. The resources are reported within a mine stope optimised volume using a US$1700/oz gold price. This target was the focus of resource conversion drilling in 2021.
Since reporting the inferred mineral resource on 31 March 2020, 7046 m in 16 drill holes has been completed, with a further 11 500 m planned in 2022. The 2021 drill programme focused on defining and converting inferred resources in the higher grade and shallower levels of the deposit as defined by a preliminary and conceptual mine design. An updated resource estimate is expected to be released on 31 March 2022. The 2022 programme will focus on resource conversion at deeper levels.
The results for the 2021 Palomino resource conversion drilling programme to date have improved confidence in grade distribution and continuity of mineralisation and returned similar grades to historic drilling however, in general, reduced downhole thickness when compared with the resource block model. Significant downhole intersections from the 2021 infill resource conversion program include:
- DDH1115: 7.77 g/t Au over 101.3 m.
- DDH1108: 5.91 g/t Au over 67.1 m.
- DDH1103: 6.39 g/t Au over 51.5 m.
The style of mineralisation at Palomino is similar to the Horseshoe deposit, with thick zones of fine-grain gold hosted by pyritic and silicified siltstone and intrusive rocks at the metamorphic volcanic and sedimentary contact. The southeast margin of Palomino is defined by the 70-75° SSE-dipping siltstone-dacite contact. Several 1 – 25 m barren sub-vertical NNW-striking post-mineral diabase dikes cut mineralisation.
Horseshoe Extension Target
Horseshoe Extension is located approximately 200 m SW of the Horseshoe Reserve and has the potential to leverage off future underground development. To date, approximately 15 279 m and 29 holes have been drilled on the Horseshoe Extension Target and have defined a zone of mineralisation that led to resource definition drilling in 2021. No resource estimate has been completed. A further programme of 3500 m is scheduled in late 2022. Significant downhole intersections from the 2021 programme include:
- DDH1096: 7.45 g/t Au over 43.4 m.
- DDH1101: 4.09 g/t Au over 24.7 m.
- DDH1102: 5.49 g/t Au over 13.4 m.
Mineralisation is similar to the Horseshoe and Palomino deposits, with fine-grained gold hosted in pyritic and silicified mudstones and intrusive rocks. The southeast and upper extents of mineralisation are bounded by the SSE-dipping siltstone-dacite contact. A 5 – 10 m barren sub-vertical dike NNE-striking post-mineral diabase dike cuts mineralisation.
Pisces is located approximately 600 m SSW of Horseshoe and is in the early stage of target definition. Given its proximity to Horseshoe, other advancing exploration targets and intercepts returned to date, further drilling is envisaged once Palomino and Horseshoe Extension are further advanced and the geological understanding increases. Between December 2011 and August 2012, 2530 m in three holes were drilled with encouraging downhole intersections including:
- RCT0165: 3.14 g/t Au over 24.4 m.
- RCT0205: 4.65 g/t Au over 14.4 m.
- RCT0209: 7.4 g/t Au over 7.6 m in hole, including 27.22 g/t Au over 1.2 m.
Read the article online at: https://www.globalminingreview.com/exploration-development/25022022/oceanagold-provides-haile-gold-mine-drilling-update/