Elizabeth Hill is historically one of Australia’s highest grade silver mines and has produced over one million ounces at an average of 2,195 g/t Ag (70.24 Oz/t Ag) from an initial resource of just over four million ounces. The deposit was also unique for the exceptional native silver nuggets including, as previously reported, a single 180 Kg nugget. Mining ceased in 2000 due to a depressed silver price and a fall out between the JV partners East Coast Minerals and Legend Mining hence the remaining considerable untapped resource.
Limited sporadic exploration in the ML was done after mining ceased up to 2009 however numerous targets remain to be further tested to follow up on historical work as well as new targets not yet tested.
The Elizabeth Hill Silver Project is situated approximately 45 km south of Karratha in the Achaean Pilbara Block of the Pilbara Craton. Grid power and groundwater are available on site, and the area has an abundant skilled workforce nearby.
The project area is located over the eastern part of the Munni Munni Intrusive Complex, at the contact of basement granites and the Munni Munni sequence. Localised geological controls on the Elizabeth Hill mineralisation appear to be a structurally controlled southerly plunging shoot, occurring along the eastern boundary of the Munni Munni fault. The Munni Munni fault is a major north-south regional structure with a horizontal displacement in excess of 500 m, along which the Elizabeth Hill Mineralisation has been intersected over only a 100 m north-south zone along the boundary of the fault.
|Commodity||Silver, Nickel, Copper, PGE|
|Location||Pilbara, Western Australia|
|Deposit Style||Remobilised hydrothermal Ni–Cu ± Ag ± PGE system|
|Key Attributes||High grade silver deposit partially mined with numerous Ag/Cu/Ni/PGE anomalies|
|Asset Stage||Resource update plus resource definition|
|Results||Pure silver intersection, average mine grade was 2,195 g/t Ag (70.24 Oz/t Ag)|
|Next Phase of Work||Review remaining resource potential, local and regional trenching and target generation|
Historical Data Review
From initial data review work it is apparent that there remains both underexplored resource potential within the existing ‘mine’ as well as an ‘open pit’ surface resource and extensions of the deeper mineralisation some of which has been partially mined to date and some of which has not been fully tested to date.
Initial review of historical records and technical reports by Alien confirms evidence of untested further high-grade mineralisation. Due to the abundance of native silver in the main mineralised system reported in historic reports and as evidence from the unique nuggets extracted to date and with single assays returning up to 30,000 g/t Ag (900 Oz/t Ag) it is evident that this deposit contained and still contains exceptional high-grade silver.
Alien has identified several significant priority exploration targets based on a combination of limited historic exploration on such targets, early-stage work outlining mineralisation but not having been followed up as well as simply no work having been carried out to date.
Trenching and Drilling POW
Alien’s Program of Works (“POW”) has been approved by the Western Australia Mines Department for initial trenching and drilling at the Elizabeth Hills Mining Licence. The POW covers up to 1.25 kilometre of trenching programs and 4,000m of drilling (RC and diamond drilling). Trenching programs to test for new or repeat silver orebody due south of existing deposit. Drilling program to target the historical resource area and to test for potential strike extensions. Field exploration is underway started in mid-December and will run for a number of months.
Geophysical Data Acquisition
Alien acquired an aeromagnetic survey for Elizabeth Hill and the surrounding Munni Munni North tenement. Alien and Southern Geoscience Consultants (SGC) used this new data to identify numerous targets. The highest priority of these have been used in the planning of the initial trenching work.
Trenching and Drilling Programme
Alien mobilised a diamond drill rig to commence its inaugural drilling program at the Elizabeth Hill Silver Project during August of 2021, 8 diamond core holes for a planned total of 650m designed to test for extensions to the known mineralisation both along strike and at depth and to complete initial verification work (QA/QC) on historical drilling. The program also aimed to test for a much larger mineralised system the Company believed is present at the site. Historically, the vast majority of holes were very poorly sampled and assayed with the majority only being assayed for silver. Numerous references of disseminated sulphides were made in the geological logging but never fully followed up along with several significant anomalies of copper, nickel and PGEs. Alien will carry out a full suite analysis on all relevant drill core to get a more detailed understanding of the potential of the Elizabeth Hill orebody and its envelope.
Interm Drilling Results
Currently, around 753m has been drilled as part of the ongoing drill programme at Elizabeth Hill, including:
- 211 metres of diamond core drilling (4 holes); and 542m of RC drilling (6 holes)
- 14 RC holes for approximately 1,100m remain, which will test targets along strike of the main orebody and at the nearby J-reef
Further to the announcement of 9 September 2021, the Company advises that it has switched to a reverse circulation (RC) drilling rig at the Elizabeth Hill Silver project. The RC rig will complete the remaining planned diamond holes, 4 of the original 8, which as advised were targeted at the historic silver orebody to get a better understanding of the grade, orientation and potential for a mineralised polymetallic halo which the Company believes exists around the original orebody. The RC programme will also test other targets along strike from the mine and the surrounding J-Reef target to the east and south of the orebody within the Elizabeth Hill mining licence.
From visual inspection of the core to date there appears to be some significant mineralisation outside of the historic silver orebody, which was what the Company believed to be the case following the recent detailed data review.
Multiple occurrences of visible silver have been identified in drill core recovered from shallow drilling completed to date
- Additionally, visible copper mineralisation has also been identified
- Significant sulphides also identified in core associated with copper and nickel mineralisation
- Indications from the pXRF imply some very high-grade silver readings with current maximum of 21,800 g/t silver (700 Oz/t Ag), 5% copper, 1.1 % Nickel as well as highly anomalous Cu, Ni and Zn readings over consistent interceptions
Logging and core-cutting has been completed on all the diamond core and 247 samples submitted to Bureau Veritas Laboratory in Perth for full suite analysis. It is anticipated that the initial results will be available in late November.