- JORC 2012 Resource announced 2 February 2021: 6.20 Mt at 2.0g/t gold, 80g/t silver, 2.7% zinc, 1.6% lead and 0.2% copper
- Resource is part of a larger mineral system extending over 9 km SE with extensive gold, copper and base metal workings
- Located 20 km along a broad structural zone from McPhillamys 2.3m oz gold deposit and surrounded by historical prospects - Mt Shorter, Mt Lindsay, Ophir and Caleula
- 2020 review highlighted Lewis Ponds is a gold and silver resource with base metal credits (Zinc, Copper & Lead) with potential mineralisation spread both east, west and north
- Lewis Ponds metal zonation, gold rich in the north and copper rich in the south
The 100% owned Lewis Ponds project covers approximately 148 km² located 15 km east of Orange (EL5583). This is a high priority project for Godolphin due to the extensive historic gold and base metal workings, with a Mineral Resource estimated at 6.2 million tonnes at 2.0g/t gold, 80g/t silver, 2.7% zinc, 1.6% lead & 0.2% copper and classified as Inferred in accordance with JORC (2012) (ASX announcement dated 2 February 2021).
The Lewis Ponds area was an active mining centre from the early 1800s until the 1920s. The workings were centred around two major areas being the Lewis Ponds and Tom’s Mines. All ore was processed at the Lewis Ponds mine’s treatment facility and smelter. The project hosts massive sulphide and shear hosted lead/zinc with associated precious metals, with copper to the south and a potential later stage gold overprint. Historical mining, drilling and exploration at Lewis Ponds focussed on sedimentary base metal models and not gold.
Work by Godolphin team during 2021 confirmed significant gold and multielement anomalism at Lewis Ponds similar to the nearby two-million-ounce McPhillamys Gold Deposit. The McPhillamys Gold Deposit is one of Australia’s largest, under development open pittable resources situated 20 km south east along the Godolphin Fault Zone.
During 2022 Godolphin completed a four-hole reverse circulation (RC) drill program at the Quarry Lode, testing for mineralisation near surface and to the northwest of the current MRE. All four holes intersected gold, silver and base metal mineralisation and was followed by the completion of a soil sampling program in Q4 north of the Lewis Ponds deposit. The aim of the 161-sample program was to identify zones of elevated gold and base metals along strike of the Lewis Ponds MRE. The program identified a 400m long zone of >16ppb gold with a peak result of 230ppb gold. A number of smaller zones reporting +16ppb gold occur across the sampling area and suggest a northerly extension to the Lewis Ponds resource. The findings from the historic VTEM Survey also provide support for continued mineralisation to the north of Lewis Ponds, and works will continue in FY23 to expand the existing Mineral Resource Estimate.
The current Mineral Resource Estimate was announced on 2 February 2021. Mineral Resource Estimates have previously been reported in 2005, 2016 and 2019.
The Lewis Ponds Inferred Mineral Resource, reported at a 3.5g/t gold equivalent (AuEq) cutoff, is estimated as 6.2 Mt at 2.0g/t gold, 80g/t silver, 2.7% zinc, 1.6% lead and 0.2% copper and is classified as Inferred in accordance with JORC (2012). Resources have been modelled in fresh rock only, extending from 50 to 700m below surface. For more details, including assumptions, see the ASX announcement dated 2 February 2021.
Note: The Lewis Ponds Lewis Pond met test-work produces high grade concentrates MRE utilises a 3.5g/t gold equivalent cut-off within mineable shape volumes that may include internal dilution. Tonnage estimates have been rounded to the nearest 0.1 Mt and contained metal to the nearest 1,000 tonnes. Estimates may not sum due to rounding.
The Lewis Ponds area was an active mining centre from around 1884 till the 1920s. The workings were centred around two major areas; Main Zone (also called Spicers Mine) and Tom’s Zone. Main Zone was actually the site of a smelter and an adjacent limestone quarry – postulated to be a flux source. Spicers Mine was reported to have produced around 6000 t of ore at 6.7% lead and 187 g/t silver (Rowe, 1999). Tom’s Zone was reportedly a pyrite mine and was in operation from 1913 to 1921.
Historical workings are extensive, consisting of numerous shafts (mostly collapsed and shallow) and shallow surface workings. These locations were mapped by Ardea Resources to assist in identifying the surface expression of mineralisation and hence assist in the creation of a geological\mineralisation model.
Around two to three kilometres south of the Main Zone workings, there is another group of workings including; Mt Nicholas, Brittania, Icely and Ophir Copper Mine.
In the western part of the tenement, around Mt Bulga, there is a line of workings and mineral occurrences running over a distance of approximately 6 km. The Mt Bulga Mine was reported to have a copper grade of 6.5% and also has a historical resource from 1970.
In the far northern part of the tenement, west of Summer Hill Creek, there are numerous workings and occurrences around the historical Mt Lindsay copper mine.
The Lewis Ponds deposit lies on the east limb of the Mullions Range Anticline and is hosted within the Late Silurian Mumbil Group. The actual mineralisation is hosted within the Anson Formation, a fining up sequence from a conglomeritic base to siltstones at the top. The stratigraphic sequence has been metamorphosed to lower greenschist facies. Other deposits in the region with similar mineralisation styles include; Daydawn, Calula, Mt Lindsay, Icely and Mt Bulga.
Within the sulphide lenses at Lewis Ponds, alteration varies in intensity, mineralogy and distribution. Dip of the mineralised zones is generally steep to the northeast, however they can range from vertical to more steeply westerly dipping.
The most prominent regional structure is the Lewis Ponds Fault, located less than one kilometre to the west of Lewis Ponds, which is interpreted as a splay off the Godolphin Fault.
Two series of faults have been noted at Lewis Ponds, one regular set strikes southwest-northeast and dips to the northwest and a second dipping steeply and striking east-west.
The Lewis Ponds polymetallic deposit is a stratabound and disseminated sulphide system and is historically considered to be of a VHMS type. Godolphin has documented a later stage deformation and an orogenic overprint that has introduced a component of remobilisation and the introduction of silica respectively into the system, as well as flexuring of the stratigraphy.
Agnew (2002) concluded that Tom’s Zone was a sheet style VHMS deposit formed at or near the sea floor, which has later been deformed, remobilised and fluids introduced by the Lewis Ponds Fault. The Main Zone however has similarities with carbonate-hosted replacement deposits, where sulphides have infiltrated into the pore spaces of poorly sorted breccias. Textures within the sulphides indicate rapid sea water quenching.