The Ravenswood Project is located 90 km south of Townsville and 10 km west of Ravenswood in north Queensland. The Project covers an area of 548 square kilometres and is located near the historical mining centre of Charters Towers and the multi-million ounce Ravenswood goldfield. The Project comprises four granted tenements, namely EPM26041, EPM26152, EPM26303 and EPM26304.
Gold has been mined at Ravenswood over a 150-year period with alluvial gold discovered in the area in 1868. Initial production up until the time when early mining ceased in 1917 is estimated to have been 950,000oz at a grade of around 30 g/t gold. In modern times, mining resumed in 1987 and continues today with total production (historical and current) of more than 4Moz from the Ravenswood Area, which hosts Proven and Probable Ore Reserves of 1.3Moz and Mineral Resources of 1.0Moz (see Resolute Mining Limited 2015 Annual Report).
The Project is considered prospective for porphyry molybdenum / copper and/or gold mineralisation, intrusive related gold mineralisation, breccia-hosted gold mineralisation as well as other hybrid intrusive-related styles of mineralisation including carbonatite-related rare-earths mineralisation.
The dominant rock types within the Ravenswood Project are typically I-type calcic hornblende-biotite granodiorite to tonalite of the Ravenswood Batholith of Middle Silurian to Middle Devonian age.
A major structure, the Mosgardies Shear Zone, cuts east-west through the Ravenswood Batholith adjacent to three gold centres. The shear zone is up to 2.5 km wide. The main reef at Ravenswood, the “Buck Reef”, is contained within the Mosgardies Shear Zone. The majority of faults in the area are transverse to the Morgardies Shear Zone and trend 30o to 40o either side of north. The bulk of the auriferous quartz reefs and leaders are hosted by shears with NW to NS orientation.
Podosky’s Gold Prospect
The presence of high-grade gold mineralisation at the Podosky’s prospect (located on a small Mining Lease, ML 10315 held by Kitchener Mining NL, which is excised from Stavely’s Exploration Permit 26041) highlights the potential for high-grade gold mineralisation in this area.
Significant high-grade drill intercepts from the Podosky’s prospect include (see Haoma mining Quarterly Report December 2003):
- 6 metres at 16.7 g/t gold from 14 metres depth in drill hole PDR-2
- 6 metres at 13.38 g/t gold from 26 metres depth in drill hole PDR-9
- 5 metres at 12.06 g/t gold from 29 metres depth in drill hole PDR-23.
The Podosky’s mineralisation trends into EPM26041.
Porphyry Copper-Molybdenum-Gold Prospects
There are four identified porphyry copper-molybdenum-gold prospects – The Bank, Keane’s, Barrabas and Turkey Gully on EPM26041, none of which have had any drilling since the early 1970s. Surface rock chip results of up to 49% copper, 0.24 g/t gold, 0.2% molybdenum and 1,793 g/t silver have been returned from these prospects.
Historical drill results from the Keane’s molybdenite prospect include:
- 45 feet 3 inches (13.8 metres) at 0.26% molybdenum
- 1 foot 7 inches (0.38 metres) at 2.26 ounces (70.3 g/t) silver per tonne
- 9 feet (2.74 metres) at 9.6 pennyweight of gold plus silver (15 g/t) of which 0.58 g/t was gold.
Rock chip sampling in 2017, returned high-grade copper and gold results from the Keane’s porphyry prospect, including 18.3% copper, 2.48% copper and 0.94 g/t gold.
There are numerous historic workings south of the Burkdein River in what is known as the Dreghorn Goldfield including Queenslander, Albion, Ellen Ross, Clinker, Sundown, Sunrise, Hidden Treasure and Rejoice. Mineralised quartz+sulphide veins of the Dreghorn Goldfield are hosted in granodiorite and granite phases of the Silurian Carse-O-Gowrie Granodiorite.
The Dreghorn mines were worked from 1860 to the early 1870’s. Historic production from the mines was:
Ellen Boss 848.8 ounces gold from 630.65 t average grade 46.6 g/t gold
Albion 422.75 ounces gold from 184.9 t
Queenslander 76.77 ounces gold from 223.3 t
Clinker 18.99 ounces gold from 21.26 t average grade 62 g/t gold
Sundown 206.7 ounces gold from 48.11 t
Sunrise 75.88 ounces gold from 35.03 t
Hidden Treasure 25.17 ounces gold from 37 t
Rock chips taken in 2017 returned high-grade gold results from the Albion / Queenslander trend including 68.3 g/t gold and 6.45 g/t gold.
Recent soil and rock chip sampling of the NNW- and NNE-trending Ellen Boss, Ellen Boss East, Rejoice and Percy Keene structures have shown them to have Au+Cu+Bi±As geochemical signatures typical of intrusive-related gold systems (IRGS) like Ravenswood.
Elphinstone Creek Gold and REE Prospect
Very high-grade stream sediment results were returned from reconnaissance sampling in the tributaries of the Elphinstone Creek, including 6.28 g/t gold, 1.1 g/t gold, 0.45 g/t gold and 0.42 g/t gold in an area of widespread anomalism but with no known hard-rock workings.
Stream sediment samples taken in the tributaries of the Barrabas and Elphinstone Creeks returned highly anomalous rare earth element results. One sample in the vicinity of the high-grade gold results assayed 0.19 g/t gold, 0.91% cerium, 0.43% lanthanum, 0.31% neodymium, 926 ppm praseodymium and 514 ppm samarium.