Highlights
- Historical gold mining area with substantial historical workings
- High gold samples in rock chips and soil from work conducted in 2019 and 2020
- Multiple walk up drill targets identified across land package
- During the 2021/22 year, 1,139m of RC drilling was completed across Gundagai North and Gundagai South prospects, targeting historic workings and mapped veins
- Diamond drilling at Gundagai South Project intersected extensive disseminated pyrite, stringer and vein-hosted sulphide mineralisation at both the Surprise Hill North and Big Ben prospects
- Soil and rock chip sampling followed up the drill program returning encouraging results and showed continuation of broad gold mineralisation enhancing exploration potential
- Rock chip sampling was conducted during the soil sampling program and identified high-grade gold associated with quartz veins in flow banded rhyolites. Sample GRR0230 returned an outstanding gold value of 10.8g/t with visible gold in the sample (ASX release 27 May 2022 ASX: GRL “Exploration Update”). This result shows there is potential for the area to host economic gold mineralisation. Further, the sample also identifies the extension of the flow banded rhyolites that host quartz veins with gold. These will be a key focus for future exploration.
- Results from soil and rock chip sampling at the historic Oaks Gold Mines area on Gundagai North tenement identified a 2.2km long zone of +1,000ppm barium and anomalous gold.
“Recent drilling, rock chip and soil sampling results at Gundagai South have provided Godolphin with further insight into the geological make‐up of the Project. While the drilling at Surprise Hill North does not fully explain the surface soil anomalism, it will give us an indication on what next steps need to be undertaken for future exploration. To have visible gold in a surface rock sample from Big Ben is very encouraging and we will need to evaluate this along with the latest drill results to design the best possible path forward for these two prospects.”
— Managing Director, Jeneta Owens, May 2022
Overview
The Gundagai tenements (GRL 100% ownership) are located in the highly prospective Lachlan Fold Belt. The tenements contain a number of historical gold and base metal artisanal mine workings hosted within a belt of basaltic rocks intruded by quartz phenocryst porphyritic dykes or sills.
This area has a long history of mining and hosts abundant historical workings, mainly for gold, but also minor copper. The area is prospective mainly for orogenic gold and Intrusive Related Gold Systems, but also has the potential for VHMS and porphyry hosted gold-copper deposits.
Gundagai North (EL8586): At Gundagai North geological mapping had previously identified several key targets located in three prospects to be drill tested (Emu, Johnson’s Hill & Manton’s). Gold mineralisation at Gundagai North is hosted in quartz veins within porphyritic dykes which intrude Silurian sediments and volcanics, and trend in a general north-south direction. Extensive historical mining has taken place at both Emu and Johnston’s Hill, and artisanal mining is evident at the Manton’s prospect.
Gundagai South (EL8061): At Gundagai South highly anomalous gold-in-soils, rock chip samples and mapping had previously identified key drill targets at the Surprise North, Highway and Stoney Creek South prospects. As at Gundagai North, gold mineralisation at Gundagai South is located in quartz veins in porphyritic dykes or sills intruding Silurian sediments and volcanics, and trend in a generally north-south direction across the tenement. Historical gold mining has taken place at all the prospects. 2021/22 Drilling, soil and rock sampling have returned encouraging results and shown there is potential for the area to host economic gold mineralisation. Further, the sample also identifies the extension of the flow banded rhyolites that host quartz veins with gold. These will be a key focus for future exploration.
Background
The area has long history of mining and prospecting. The first gold rush within the Gundagai and Adelong area was recorded in 1848, based on both alluvial and outcropping veins. The Gundagai-Adelong goldfield was considered to be within the top ten producers for the period from 1848 to mid-1900s (Hatfield, 2007). There were numerous small mines previously worked for gold, copper, lead, zinc, chromium, magnesite, barite and manganese. There have also been noted occurrences or exploitation of asbestos, silica and talc. At the present time there are no current mining activities taking place in the area.
Geology
Rocks within the tenement consist of the Cambrian to Silurian oceanic crest, Early Silurian Tumut Trough and Late Ordovician Molong Volcanic Arc, all part of the eastern Lachlan Fold Belt. The oceanic crustal material includes; serpentinites, basalts and cherts. The Tumut Trough material is characterised by felsic volcanics, feldspar porphyry intrusives and basinal sediments. Early Devonian uplift was accompanied by felsic intrusives and rhyolitic volcaniclastics.
Late stage alluvial and colluvial cover sediments (part of the Tertiary Murray-Darling Basin) are present, mainly along and adjacent to the Murrumbidgee River.
Overall the area sits within the north-northwest trending Tumut Synclinorial Zone which is bounded to the east by the Mooney Thrust and to the west by the Gilmore Fault (Suture) Zone.
Most of the alteration noted by previous workers was alteration associated with porphyritic intrusions. This ranges from high temperature potassic and phyllic alteration through to chlorite-sericite-carbonate alteration.
Most of the gold deposits in the region have been classified as orogenic or shear hosted. Later workers have postulated that some of these deposits, due to the relationship with porphyry dykes and the presence of quartz-biotite veins, are in fact Intrusion Related Gold Systems. The base metal-gold deposits are considered to be VHMS.