PC Gold Ltd (ASX:PC2) Spring Hill Adit Re-Opened to Accellerate Asssessment of High-Grade Gold Potential
Highlights:
- All regulatory approvals secured to re-open the historical Spring Hill underground adit.
- The horizontal adit extends approximately 427m and transects the Eastern, Middle and Main Lodes of mineralisation before turning south along the Main Lode mineralisation.
- A limited portion of the resource from the Eastern zone is incorporated in the current
open pit mine plan; underground access enables the rapid assessment of high-grade
mineralisation via underground diamond drilling from the adit and bulk sample studies. - Adit provides access to the base of the historical Spring Hill underground workings, which
recorded historical production of approximately 21,170 ounces of gold at an average recovered grade of ~30g/t Au. - Significant historical drilling results proximal to the adit as shown in Figure 1, include:
o 3m @ 21.02 g/t Au from 21m – XD004
o 11m @ 4.41 g/t Au from 1m – XB008
o 8m @ 9.5g/t Au from 93m – SHDH015
o 4m @ 9.14 g/t Au from 23 – SHRC257
o 10m @ 4.68 g/t Au from 83m – SHRC151
o 5m @ 2.95 g/t Au from 83m – SHRC 152 - Significant historical drilling in the Main Lode to the south of the adit intersected:
o 15.00m @ 10.56 g/t Au from 88m in a vertical hole ending in 6.7 g/t Au – SHRC253
o 11.00m @ 5.19 g/t Au from 65m – SHDD008A
o 6.40m @ 7.01 g/t Au from 145m and 5.0m @ 6.17g/t Au from 172m – SHDD010 - The adit was previously mapped in detail in 1994 by Ross Mining NL, with material channel samples across the adit backs returning:
o 1m @ 63.2g/t Au from 365m and 1m @ 9.48 g/t Au from 366m (Middle Lode)
o 1m @ 14.5 g/t Au from 347m (Middle Lode)
o 0.8m @ 13.9 g/t Au from 233m (Eastern Lode) - PC Gold to establish the adit as a drill drive to enable cost-effective radial fan drilling to test multiple lodes up-dip, down-dip and along strike, significantly reducing drilling cost per metre compared with surface drilling.
- Expected to materially improve geological confidence within high-grade zones of Spring Hill that will be targeted for incremental ore to supplement the open pit mine plan.
- Portal refurbishment and adit re-entry are expected to be completed within weeks,
enabling near-term underground mapping, sampling and drill planning.
Overview:
PC Gold Ltd (ASX: PC2) advised that it has received all necessary approvals to re-open an existing adit at its 100%-owned Spring Hill Gold Project, located approximately 20 kilometres north of Pine Creek in the Northern Territory.
The adit 1, located on the eastern side of Spring Hill, has a reported total length ~427 metres, intersecting the East, Middle and ultimately the Main Lodes from in and to the eastern side of
the anticline. The eastern side of the anticline is host to historical mine workings at Spring Hill that date back to as early as the 1890’s.
More recently, PC Gold announced the results of first stage RC and diamond drilling to the north of these workings that intersected high grade gold that is interpreted to be a potential extension of the eastern and middle lodes 2.
The adit entry is located approximately 200m to the east of the interpreted eastern zone mineralisation and is approximately 100m vertical below the surface of the Eastern zone and 120m vertical below the surface of the main zone.
Following successful geotechnical assessment and review in late January 2026, re-establishing underground and repurposing the adit to a resource definition and exploration drill drive will
allow PC Gold to undertake lower-cost, higher productivity underground diamond drilling, improving geological confidence in areas previously inaccessible from surface drilling, optimise future mine planning, and accelerate the evaluation pathway toward near-term development at Spring Hill.
Historical Adit and Mining Background
Gold was discovered in the 1870’s with mining activities at Spring Hill taking place between 1880 and 1905, and then intermitently until 1966.
The Spring Hill workings include a significant historical adit driven from the eastern side of the hill, originally commenced in 1933 at a horizon approximately 120 metres below the Main Lode surface exposure. The level was subsequently extended over several campaigns to a total length of approximately 427 metres by 1949, intersecting the East, Middle and ultimately the Main Lodes.
Underground access via this adit supported limited but high-grade production from the East Lode between 1959 and 1966, yielding approximately 649 ounces of gold at an average grade of 18.6 g/t Au. Historical records indicate broader mining at Spring Hill prior to 1950, produced a cumulative ~21,170 oz Au, primarily from high-grade shoot development within the Main Lode at grades averaging an ounce per tonne recovered.
The ore mined from Spring Hill was processed at a stamp batery, parts of which remain onsite today on the eastern side of Spring Hill (Plate 3).
Location of the Eastern, Middle and Main Zones
The Eastern, Middle and Main zones sit on and to the east of the Spring Hill anticline as shown in Figure 3 below. All historical mining activities were confined to these three lodes within the oxide zone, down to a vertical depth of 108 metres.
The approved open pit mine plan for Spring Hill envisages a primary open pit covering the Hong Kong and Macau zones, together with a smaller shallow starter pit on the Eastern zone. These pits are the subject of a feasibility study currently under way, and the integration of the adit and proposed underground activities does not interfere with the historical adit or any planned underground exploration or mining activities at this stage.
High Grade Drill Intercepts Near the Adit
Historical diamond and RC drill programs have intersected high grade mineralisation proximal to the adit including:
- 3m @ 21.02 g/t Au from 21m – XD004
- 11m @ 4.41 g/t Au from 1m – XB008
- 8m @ 9.5g/t Au from 93m – SHDH015
- 3m @ 9.14 g/t Au from 23 – SHRC257
- 10m @ 4.68 g/t Au from 83m – SHRC151
- 5m @ 2.95 g/t Au from 83m – SHRC 152
The mean grades in the above intervals have been calculated on a 2.5g/t Au lower cut-off grade with no upper cut-off grade applied, and maximum internal waste of 1m.
The above holes were all drilled into the northern end of the MRE and included the Main, Middle and Eastern lodes MRE. Drill access from underground will certainly enhance the Company’s ability to properly follow the holes up.
Material drill holes to the south of the adit drilled during TM Gold Pty Ltd ownership, a 100% owned subsidiary of PC Gold Ltd, returned
- 15.00m @ 10.56 g/t Au from 88m in a vertical hole ending in 6.7 g/t Au – SHRC253
- 11.00m @ 5.19 g/t Au from 65m – SHDD008A
- 6.40m @ 7.01 g/t Au from 145m and 5.0m @ 6.17g/t Au from 172m – SHDD010
In addition, the northern end of the Hong Kong and Macau lodes is also potentially accessible where historical RC and diamond drilling have intersected high grade mineralisation including:
- 8m at 7.88g/t Au from 145m – SHRC131
- 9m at 6.19g/t Au from 97m and 3m @ 4.35g/t Au from 205m – SHRC137
Note that the current end of the adit is approximately 70 metres south-east of the cross section shown below in Figure 4.
Next Steps
In preparation for adit rehabilitation and access re-establishment, PC Gold will undertake:
- Ground support assessment and safety inspections of the historical workings.
- Necessary upgrade works in accordance with NT regulations.
- Review of proposed underground drill program, enabling targeted short-hole diamond drilling.
- Review of historical geological and geotechnical mapping of exposed mineralisation.
- Detailed mapping and sampling of mineralisation.
- Application for drilling activities within the adit and/or established ore drives that can be safely accessed. Initial underground drilling is expected to commence by mid-2026, following completion of the safety and preparatory activities.
Company Notes:
Executive Chair, Ashley Pattison stated:
“Securing approval to enter the Spring Hill adit is a major milestone for PC Gold. Underground access provides a highly cost-effective means of underground diamond drilling directly within the mineralisation and testing its extensions, significantly improving our geological understanding of the Eastern, Middle and Main Lodes.”
“Portal refurbishment and adit re-entry is expected to be completed within a fortnight, after which the Company will commence detailed underground mapping and sampling. This work will be integrated with existing drilling to design a targeted underground diamond drilling program. Importantly, the adit’s position approximately 120 metres below the Main Lode, allows down-dip extension of high-grade mineralisation to be assessed efficiently.”
“The adit will be repurposed as a resource definition and exploration drilling platform. We are devising an underground diamond drilling program to aggressively delineate the vertical and
along strike extent of mineralisation proximal to the adit.”
“Our aspiration is to delineate a high-grade mineral resource that demonstrates the potential for early high-grade production at Spring Hill and can be integrated into the development plan for a much broader resource base. We look forward to providing further detailed updates on the adit re-entry, sampling and underground diamond drilling”
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