Pinnacles Mine

Pinnacles mine hosts a Mineral Resource Estimate of 6.0Mt at 10.9% ZnEq

Overview

Location
15km south-west of the city of Broken Hill, New South Wales
Property
Mining Leases ML 4436, ML 5627, ML 5835, ML 5836, ML 5849, ML 870 and Environmental Protection Licence EPL 5261
Mineralisation
Metamorphosed VMS (volcanic hosted massive sulphide) deposit
Mineral Resources
6.0 million tonnes @ 10.9% ZnEq (4.7% Zn, 3.3% Pb & 132g/t Ag)
Exploration Target
6.0 - 15.0 million tonnes @ 2.0 - 4.0% Zn, 3.0 - 6.0% Pb, 40 - 125g/t Ag)
Mining Method
Combination of underground and open pit proposed
Ore Transport
Via existing haul road and public roads to Rasp site
Processing Method
Grinding, flotation, thickening and filtration (via Rasp Processing Plant) Similar recovery profile to Rasp ore
View overlooking Broken Hill from the Line of Lode Memorial

Considered to be one of the highest grade and shallowest deposits in Broken Hill, the Pinnacles Mine remains relatively undeveloped, with only small-scale historical mining targeting the rich Galena (lead ore) lodes

Resources, Exploration & Development

Pinnacles Mine near Broken Hill storage and processing structures

Pinnacles Corporate History

  • Privately owned by the Williams family since 1954
  • Williams family has defined the clear potential of Pinnacles with extensive exploration drilling over the past 20 years, including discovery of the Perseverance ore body
A front-end loader at work in Broken Hill

Mineral Resource Upside

  • Current Mineral Resources based on >55,000m of drilling to date

Growth of Perseverance

  • Initial focus on Mineral Resource growth at Pinnacles
  • Unassayed core along strike from the existing Perseverance ore body, with strong potential for material tonnage increase
  • Targeting a near-term completion of assay work in conjunction with infill and extension drilling to increase both Mineral Resource size and confidence

Pinnacles Development

  • On completion of drilling, BHM will immediately start a Mining Expansion Study to assess the incorporation of Pinnacles ore into the Rasp Processing Plant
  • Similar mineralogical and metallurgical characteristics to Rasp ore based on historical exploration and production data

Pinnacles Mine History

Mining started

to a depth of 80m below surface only

Planned Pinnacles IPO

stopped due to global financial crisis

Acquisition

by Edward Williams

Operations were placed on care and maintenance

due to Covid

The Pinnacles Mine, located 15km south-west of the Broken Hill township, is considered to contain one of the  highest grade and shallowest known deposits in Broken Hill. The Pinnacles Deposit remains relatively undeveloped, with only small-scale historical mining targeting the rich Galena (lead ore) lodes occurring since it was originally opened in the 1880s as an underground lead-silver mine. 

For over 70 years the Williams family have owned the Pinnacles Mine, following its initial acquisition by Edward  Williams in 1952. The Pinnacles Mine has been progressively developed and operated by the Williams family since  this time under the leadership of Edward, his son Teddy and eventually his grandson Craig, with the later remaining the current Chairman of Pinnacle Mines Pty Ltd.

Over 55,000m of drilling has been completed at the Pinnacles Mine to date, with approximately 33,000m  occurring since 2001. In addition, approximately 22,000m of trenching has been completed at the Mine. Operations from the Edwards Pit at the Pinnacles Mine began in early 2007, producing lead oxide ore which was transported from the Mine’s rail siding to Port Pirie for smelting. The Mine was then progressively expanded to  include on site production of zinc and lead concentrate. 

Operations were placed on care and maintenance in 2020 due to Covid, however drilling has continued on site, expanding the known resource base. The Edwards Pit borders five other potentially significant deposits which make up the overall Mineral Resource for the Pinnacles Mine, including the most recent discovery of the high-grade Perseverance Deposit.

Pinnacles Exploration Target

An Exploration Target has been estimated for the Pinnacles Mine area of between approximately 6Mt to 15Mt at approximately 2-4% Zn, 3-6% Pb and 40–125ppm Ag. The Exploration Target comprises potential mineralisation below and adjacent to the current Pinnacles MRE.

The potential quantity and grade of the Exploration Target is conceptual in nature and there has been  insufficient exploration to estimate a Mineral Resource, and it is uncertain if further exploration will result in  the estimation of a Mineral Resource.

The Exploration Target is derived from historical drilling which enabled extrapolation of the mineralised domains  (Main Lead Lode and Immediate Footwall Zinc Lode only) beyond the limits of the Inferred Resource. This extrapolation is based on the latest geological modelling with an estimation of a potential grade range sourced  from all the drilling data for the lode intersections.

The Exploration Target comprises four distinct mineralised areas, termed Consols Deeps, Consols South,  Perseverance Deeps and Perseverance East. The historical drill holes show continuity of the mineralisation at  depth and along strike, with similar overall grades to the existing resource.
The Exploration Target is considered  to be a medium term target. The intent is to continue exploration drilling along strike, down dip and down plunge  from the current Mineral Resource to verify the Exploration Target. The Company intends to commence near mine exploration shortly after Completion, which will focus on  extending the down dip and along strike extensions of the known deposit with the view to convert the Exploration Target into a Mineral Resource. 

Geological Interpretation

The lode interpretations are based on 15m spaced section lines for Consols, 25m spacing for Fisher and Pinnacles  and 50m for Perseverance. Digitising of the shapes involved snapping to drillholes on the assay grade dividers  or on logged lithology if no assays were present. A 1% zinc or lead cut-off grade was used in conjunction with  logged geology, with an allowance for minor internal dilution (generally <2m) on condition it made geological sense. The excellent underground mapping by Hopwood was also used to guide the design of the mineral lodes.  In some minor instances, the gold assays were used to aid the interpretation particularly for the zinc lodes, which tend to be more gold-rich.

The chosen grade threshold was used in an effort to establish geologically sensible domains and take into  account the likelihood of either an open pit or underground method of extraction. The mineralisation boundaries were variable in their visual sharpness, with some contacts clear cut and others more diffuse. The wireframes  were used as constraints for the composite selection and grade interpolation.

No oxidation surfaces were designed mainly due to a lack of data and a lack of penetrative oxidation impacting  the lodes. The recent Consols mining directly shipped any oxidised material to the Port Pirie Smelter to be used  as a flux.

The existing interpretation honours all the available data; an alternative interpretation is unlikely to have a  significant impact on the resource estimates.