Mt Egerton grant of Exploration Licence
Greatland exploration portfolio enhanced by new Mt Egerton gold-copper project
Greatland Gold plc (AIM: GGP) announced that it has been granted a new Exploration Licence E52/4342 (Woodlands) covering 134km2 as the inaugural tenement in the Mt Egerton Project (Mt Egerton).
Highlights
- Exciting new gold-copper exploration project established in the Gascoyne region, located 230km north of the Meekatharra gold camp
- Greatland targeted the region as potentially having mantle tapping structures, an essential ingredient in large scale gold and copper systems
- Woodlands tenement includes a 25km strike length in a structurally complex geological setting which is potentially a very favourable mineralisation trap site
- The tenement is significantly under-explored, with open file data recording very limited drilling and soil sampling, none of which was assayed for gold
- Indigenous Land Use Agreement already in place provides expedited pathway to on-ground exploration work
Greatland Managing Director, Shaun Day, commented:
“We are delighted by the grant of the Woodlands tenement at our new Mt Egerton gold-copper project, which further enhances our excellent exploration portfolio with a new front in a highly prospective region of Western Australia.
Our exploration team identified Mt Egerton as an excellent regional and local geological setting for the discovery of major gold and copper deposits. With the successful grant of our first tenement, we will now work to compile and interpret available data to plan systematic, targeted exploration on the ground in the near future.
We are proud of Greatland’s proven track record of discovery and exploration success, and Mt Egerton presents a further opportunity to put our advanced exploration techniques to work in an under-explored region in pursuit of tier-one gold and copper deposits.”
Native title and land access
The newly granted Woodlands tenement is within the Nharnuwangga Wajarri and Ngarlawangga (NWN) native title determination and is covered by an existing Indigenous Land Use Agreement (ILUA) signed between the Government of WA and the Jidi Jidi Aboriginal Corporation (JJAC). The ILUA applies to any tenure within the area by the tenement holder entering into a prescribed form heritage agreement with JJAC, which Greatland has requested. This is expected to provide a significantly expedited pathway to on-ground exploration activities at Woodlands.
Geological setting
The Mt Egerton Project lies within an east west trending wedge of folded Proterozoic metasediments developed in the Edmund Basin (Figure 1), wedged between the northern margin of the Archean Yilgarn craton and the southern margin of the Pilbara Craton to the north. This is a major deep seated structural boundary which is interpreted as a likely conduit region for metals from the mantle, and a highly prospective setting for the discovery of gold and base metals deposits.
Figure 1: Mt Egerton Project location on Geoscience Australia Archean and Proterozoic geological provinces.
Local geology
Within the Woodlands tenement, the geology is dominated by west-north-west trending isoclinal folding, creating domal anticline and syncline pairs, including the Lyons River Anticline within Proterozoic basin fill sediments (Figure 2). These sediments include reactive calcareous units within the Devil Creek, Ullawarra, Irregully and Discovery formations, which can act as chemical traps for mineralisation.
The regional scale Quartzite Well Fault (Figure 1 and Figure 2) bisects the tenure and truncates the folded stratigraphy. Second order splays off this deep seated fault structure have been confirmed in drilling (25-75km) to the east to have elevated gold values, increasing the prospectivity of similar untested fault splays within Woodlands.
Figure 2: 1:100,000 scale state interpreted bedrock geology and previous work.
Historical work
Woodlands is historically underexplored, with only a single line of 6 reverse circulation (RC) drillholes (Figure 2) completed by Western Mining Corporation (1993) in the south of the tenement, according to the Geological Survey of WA (GSWA) open file data. Only a limited suite of elements were assayed for, and critically none of the samples were tested for gold. The cover depth in drilling is inferred to be approximately 60 metres and increasing to approximately 100 metres in faulted ground. The depth of cover is interpreted to shallow towards the west where it outcrops in the Lyons River Anticline and in the north of the tenement.
Historical surface sampling programmes carried out by Western Mining (1992) and Abra Mining (2008-2011) included 559 samples completed along the North and East parts of the tenement (Figure 2). As with the historical drilling, gold was not assayed for. Weak copper anomalism appears to be associated with particular lithological units and is likely in the sediments at the time they were laid down, rather than an indicator for mineralisation, post deposition.
Prospectivity
The exploration model targeting gold and copper mineralisation at Woodlands is that movement on a regional scale fault causes partial melting of the mantle at depth (Figure 3). These hot metal rich fluids migrate to the surface preferentially utilising second order faults. Impermeable units in anticlines act like an overturned bowl trapping the rising fluid and pooling it beneath them. Calcareous units react with this cooling fluid and at the same time dissolving creating open space. This effect changes the fluid chemistry and creates a pressure drop forcing the metals to drop out of solution and deposit.
The Woodlands tenement shows evidence of all of the above requirements for gold mineralisation, including a major regional fault, mineralised splays, anticlines and reactive rocks. The lack of outcrop has meant that the area has remained untested, with no historical gold assays completed on the tenement. Greatland considers the Woodlands tenure to be highly prospective for gold and copper mineralisation.
Figure 3: Illustrative mineralisation model.
Planned work
Work at Mt Egerton has commenced and is focused on:
- Signing the ILUA prescribed form heritage agreement
- Completing a desktop review to refine the geological model at Woodlands to determine the most prospective locations for possible chemical and physical trapsites
- Defining programmes to effectively test the main structural “plumbing” within the tenure for mineralisation and follow these to the trap sites
- Field reconnaissance
Contact
For further information, please contact:
Greatland Gold plc
Shaun Day, Managing Director | info@greatlandgold.com
