Summary
- Pre-JORC Compliant Resource of 4.05Moz Ag at 200g/t Ag cut off
- 1.2Moz @ 70.6ozt/t Ag (2195g/t Ag) mined in it’s single year of operation (1999-2000)
- Bonanza Grade Silver hit during Alien’s initial drilling with 19.7m @ 113ozt/t Ag as well as bulk tonnage suggestive intercepts such as 52m @ 22.6ozt/t Ag
- Historically Australia’s highest grade silver mine noted for its exceptional native silver nuggets including Australia’s largest ever silver nugget the 145kg Queen Karratha
- Mining ceased in a single day due to a fall out of JV partners thus leaving a considerable untapped resource
- Alien has erected headframes over both existing shafts and has purchased necessary equipment for dewatering, camp construction and mine re-opening
Local Geology
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. The area also hosts an ultramafic unit called the Judy Reef, a significant host of Ni-Cu-PGEs. VMS targets have also been identified within this mineral rich Mining Licence.
Exploration Summary
Maiden Drilling
The drill program totalled 19 holes for 1991m spread across the Project, comprising of 4 diamond drilled holes totalling 211m, with the remaining 15 holes and 1780m utilising Reverse Circulation (RC) drilling. The diamond drilling results were particularly exceptional with Bonanza Grade intersections being hit resulting in some of the highest grade silver intercepts globally in 2022. Interpretation of the below diamond core results suggest the mineralised envelope at Elizabeth Hill may be larger than work by previous explorers has suggested, with the mineralisation starting at surface in highly weathered, soft and easily extractable material.
Diamond drill results include:
- 19.7m @ 102.8ozt/t Ag (3198g/t Ag) from 5m with end of hole mineralisation of 1.7m @ 638.7ozt/t Ag (19,865g/t Ag) from 23m, in drillhole 21EHDD003.
- 24.8m @ 28.2ozt/t Ag (877g/t Ag) from 2m in drillhole 21EHDD001.
- Notable Cu, Ni, Zn, Pb and Co credits leaving potential for a larger multi-commodity resource.
RC drill results include:
- 52m @ 22.6ozt/t Ag (703g/t Ag) and 0.009% Pb from 38m in drillhole AMEHRC009
- 2m @ 49.8ozt/t Ag (1,550 g/t Ag) from 108m, in drillhole AMEHRC012, which represents a potential new mineralised zone 400m south of the Elizabeth Hill mine along the Munni Munni Fault.
- Again with notable Cu, Ni, Zn, Pb and Co credits leaving potential for a larger multi-commodity resource.
Phase 2 Drilling
This result confirmed extensions to the main silver lode, which when combined with a re-evaluation and re-interpretation of EH data strongly suggests the original EH high-grade, narrow silver vein is in fact the high-grade core of a much larger mineralised halo. As a result of multiple holes not reaching there target depth, the programme is considered unfinished by Alien, who plan to complete the drilling with diamond tails.
Mine Reopening
In January 2021, Alien commenced plans to reopen the original mine site by purchasing mining headframes, machinery and equipment to re-open and access the historic Elizabeth Hill silver mine after over 20 years of the mine lying dormant. The previous owner produced over 1m oz silver with exceptional grades of 2,195 g/t (70/oz t). Re-opening of the existing underground workings will provide access to the unmined orebody in the workings enabling detailed mapping and sampling of the orebody, to better understand potential extensions. It also provides an opportunity to update the silver resource directly from underground, and to expedite drilling of the polymetallic mineralised halo, also from underground. This will also require the establishment of an on-site camp for which Alien also has the necessary equipment.
As a critical part of the development of this project, Alien are very fortunate to have the original miner who carried out the underground development engaged to open up the historic mine. Having been untouched for over 20 years, the initial work needed will be to dewater the mine and then to re-establish the dewatering system that was already in place via the existing steel lined water bores located just northeast of the main shaft. A substantial head frame will then be installed over the main shaft to facilitate safe and approved access via a cable system to underground. Once in place, the cleaning and making safe of the underground workings will be possible.