Greatland Gold has been granted an inaugural tenement in the Mt Egerton Project, with the new exploration licence covering 134km².
Greatland’s Managing Director, Shaun Day, said that the company is delighted by the grant of the Woodlands tenement at its new Mt Egerton gold-copper project, which further enhances its 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,” Mr Day said.
“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 Western Australian Government 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, 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.
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. 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 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.
Historical work
Woodlands is historically underexplored, with only a single line of six reverse circulation drill holes completed by Western Mining Corporation in 1993 in the south of the tenement, according to the Geological Survey of Western Australia 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 60m and increasing to approximately 100m in faulted ground. The depth of cover is interpreted to be 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 in 1992 and Abra Mining in 2009-2011 included 559 samples completed along the North and East parts of the tenement.
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.
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 dissolve, 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.
Image: Henri Koskinen/shutterstock.com
