Halls Peak Zinc, Lead, Copper & Silver
Right geological setting, Halls Peak base metal province located in an area of historic high grade massive sulphide mines over an area of 4 x 5km
Several shallow, small high grade DSO massive sulphide bodies already discovered
Major miners consider Halls Peak has potential to host a large base metal deposit
Flat lying VTEM conductor around the old Sunnyside Mine fits a typical SEDEX deposit model. Consultant Geophysicists interpret this conductor to host sulphides
Main conductor setting is analogous to McArthur River Deposit (227Mt ore); Several other continuous, flat lying conductors
Geotech Consultants (the developers of the VTEM technology used) interpret the Halls Peaks Spike Island Anomaly to be similar the Caber Deposit Canada
$90,500 granted in NSW Government New Frontiers Cooperative Drilling Program. Provides 50 per cent of costs to test potential for large massive sulphide deposits
Confidence exists that the VTEM survey has potentially located sulphide deposition but economic grades and tonnage yet to be proven
Halls Peak Exploration Licenses
3 Exploration Licences in north-eastern NSW (EL4474, EL5339, EL7679) cover all known areas of mineralisation; 132 square kilometres.
The area is well known for Direct Ship (DSO) extremely high grade, small tonnage (less than 30,000 tonnes) massive sulphides.
DSO grades typically range from 19-35% Zn, 6-20% Pb, 1-4% Cu, 1-90oz Ag.
EL 4474 and EL 5339: Force Commodities holds 100%.
EL 7679: Force Commodities holds 55% in JV company.
Prime Exploration Targets
Around Halls Peak (the inferred volcanic centre) the sequence contains three target types derived from two distinct phases of mineralisation:
- Small to medium (1,000 -100,000 tonnes) sized DSO massive sulphide bodies
- Large tonnage (100,000 –100mt) massive sulphides. Drill Ready Targets Identified
- Steeply dipping, deep tapping structurally controlled Cobar-style
- VTEM anomalies (1,221 line kilometres heliborne survey flown) with potential sulphide responses including large flat lying conductors in relatively undisturbed sedimentary basins, Target – Large zinc/leaddeposits eg. HYC (MacArthur River)
- Late stage, orogenic gold mineralisation associated with altered and quartz-veined stockworked volcanics
Views on Potential of Halls Peak Supported by Major Mines
Massive sulphide deposits characteristically occur in clusters of several deposits and areas subjected to mature exploration can contain a giant deposit. Halls Peak is a prime exploration area as it has not, until now, been subjected to modern airborne geophysical exploration.
“There is undoubtedly room for large deposits to occur…. In summary it is felt that the probability of commercially interesting deposits existing at Halls’ Peak is quite high. At least three mineralised horizons involving 8,000 metres of favourable argillites are shown…” C. E. Palethorpe, BHP Melbourne Research Laboratories, 1974
“An ore body in the order of magnitude of ten million tonnes at 30% combined base metals and 150 – 300 g/t silver is possible.” AMOCO, 1983
“Halls Peak, …. is a classic sedex massive sulphide system with potential to discover a large, Mt Isa sized deposit.” Greg McKelvey, Retired Vice President Phelps Dodge sedex systems South America 2006. Mr. McKelvey has given consent to publish his findings.
The VTEM survey flown has potentially located such a predicted target
Multiple High-Grade Small Tonnage Zn, Pb, Cu, Ag Lodes
Known deposits. All deposits discovered originally from outcrop.
Several other similar-scale deposits discovered to date but not included in table below.
Note not JORC compliant. The average grades have been calculated from limited assay data, insufficient to provide an accurate measure. The measurements have been undertaken to provide both “ballpark” estimates of possible resources and readily testable exploration concepts for shallow DSO. Based on drill hole data, open file exploration reports and mapping by the Geological Survey of NSW.
Prime Exploration Targets
- Large tonnage (100,000 – 100mt) massive sulphides.
- Drill Ready Targets Identified.
Steeply dipping, deep tapping structurally controlled Cobar-style.
VTEM anomalies (1,221 line kilometres heliborne survey flown) with potential sulphide responses including large flat lying conductors in relatively undisturbed sedimentary basins, Target – Large zinc/lead deposits – eg. HYC (MacArthur River).
Geotech’s Halls Peak Heliborne VTEM Survey
Results Display Some Anomalies Consistent with Potential Massive Sulphide Deposits
Many deep conductive zones have been identified by the VTEM survey
Potential for large continuous flat lying zinc-lead-copper-silver bearing beds
Vertical conductive zones, possibly conduits to vents discharging mineralisation, have also been found
Greg McKelvey, Retired Vice President Phelps Dodge sedex systems South America 2006, after studying geochemical vectors, predicted that the potential site for the formation of a large sedex deposit would be located immediately east of the growth fault hosting the copper-rich Sunnyside and Mickey Mouse Deposits Prediction now strengthened by the discovery of a large flat lying VTEM conductor at depth at this location.
Classic ‘Textbook’ Sedex-Style Anomaly
Faults Control The Anomalies (Shown in Pink)
Figure Below has 2012 VTEM Conductors plotted on 1978 NSW Geol. Survey structure map. Precisely abuts growth faults, potentially classic feeder structures discharging into grabens! The historic mines along the main western growth fault are copper-rich, a further diagnostic characteristic – vector to discharge structure CLASSIC ‘TEXTBOOK’ SEDEX-STYLE ANOMALY FAULTS CONTROL THE ANOMALIES (Shown in pink)
NOTE: The broad conductive zones could be the response of an economic Zn-Pb-Cu-Ag sulphide body but equally could be response of pyritic carbonaceous (graphitic) black shales with sub-economic sulphides.
Normally highly Conservative Geophysicists have stated “These conductors appears to terminate against the same northeast-southwest structures which are spatially associated with several historical workings. These should be the highest priority for ongoing exploration. Evidence of source migration from early to late time towards these faults may be indicating thickening sulphide closer to the fault. This does not appear to be consistent with typical VMS systems, but may be more aligned to sedimentary exhalative (SEDEX) processes.” Southern Geoscience Consultants Pty. Ltd. 2012.
Halls Peak VTEM Conductor Setting is Analogous to McArthur River Deposit
The McArthur River SEDEX system is world class deposit. Pre-JORC geologic resource of 227M tonnes at 9.2% zinc, 3.1% lead, 0.2% copper and 41 g/t silver.
Halls Peak’s anomaly is flat lying and controlled by faults, similar to McArthur’s SEDEX structural setting.
Comparison of Halls Peak potential SEDEX Deposit (left figure in pink) with McArthur River Deposit (right).
Deep Conductor and Structure Fits Classic SEDEX MODEL, SIGNIFICANT POTENTIAL Simplest Fit.
Flat lying Conductor in Blue
Vertical Conductor in Purple
Geotech airborne Re-interpretation
A request for an opinion on a possible anomaly similar to the Caber base metal deposit in Canada, in the Spike Island area in the north east of EL7679, resulted in an offer of interpretation by Geotech Airborne.
The interpretation concluded “In general the conductive zone is complex and consists of two types of conductors: 1) steeply dipping (or subvertical) conductors and 2) subhorizontal blocky, lens or layer similar conductors. geologically the steeply dipping conductors likely reflect faults which could be channels for sulfure solutions transportation (feeding channels); and adjacent subhorizontal conductors can be interpreted as sulphide-beds.