*This article was originally written by Colin McClelland and published in The Northern Miner
The Northern Miner’s Drill Down features highlights of the best gold assays from the March 29-April 5 period. Drill holes are ranked by gold grade x width as identified by data company Mining Intelligence.
Assays from past-producing projects near Las Vegas and in Australia led the week. Nevada King Gold (TSXV: NKG) is drilling to restart the Atlanta mine in southeast Nevada. Dateline Resources (ASX: DTR) found mineralization in unexpected geology at the Colosseum project in California and Ora Banda Mining (ASX: OBM) drilled underground at Riverina-Mulline in Western Australia.
Atlanta in Nevada
Nevada King Gold drill hole AT23WS-23C.1 cut 86.3 metres grading 4.51 grams gold per tonne for a width x grade of 398 from 226.2 metres depth, the company said April 3. It included 43 metres at 7.77 grams from 256.3 metres down hole.
The drilling occurred in the north part of the West Atlanta Graben zone at the 51.7-sq.-km Atlanta project in the Battle Mountain Trend 264 km northeast of Las Vegas.
Hole AT23WS-23C.1 reveals gold distribution in a close lateral correlation with hole AT23WS-23 and helps define a northwest-trending high-grade zone along the axis of the Graben zone that is 200 metres long by 70 metres wide, Nevada King said in a release.
“The company’s multiple structure model continues to lead to thick, high-grade mineralized zones,” exploration manager Cal Herron said. “Nevada King’s success at increasing both grade and thickness can also be attributed to achieving full penetration of the low-angle unconformity that hosts most of the mineralization at Atlanta.”
The Atlanta mine produced 110,000 oz. of gold and 800,000 oz. of silver between 1975 and 1985. The site holds 11 million indicated tonnes grading 1.3 grams gold per tonne for 460,000 oz., according to a 2020 technical report. Inferred resources add 5.3 million tonnes grading 0.83 gram gold for 142,000 ounces.
Colosseum in California
Dateline Resources drill hole CM24-16 cut 88 metres grading 4.18 grams for a width x grade of 368 from surface at the Colosseum project about 90 km southwest of Las Vegas, the company said April 2. It’s on the other side of the Nevada state border in California.
The hole included 22.8 metres at 8.17 grams. Drill hole CM24-15 cut 19.8 metres at 4.19 grams. The holes show high-grade mineralization in a felsite breccia, outside of the previously targeted sedimentary breccia, the company said.
“This development is significant and the geology model will be updated accordingly,” managing director Stephen Baghdadi said. “The drilling program has been accelerated and expanded at Colosseum.”
Dateline, which acquired Colosseum in 2021 from Barrick Gold (TSX: ABX; NYSE: GOLD), is applying new software to interpret induced polarization and magnetic geophysical surveys done in the 1980s by Amselco, a unit of BP that owned the mine. The data will create 3-D images up to 200 metres deep.
Colosseum holds 20.9 million tonnes grading 1.2 grams gold for 813,000 oz. gold, according to a July 2022 technical report. It classified 258,000 oz. at 1.2 grams gold as measured, 322,000 oz. at 1.2 grams as indicated and 235,000 oz. at 1.3 grams gold as inferred.
Prospectors discovered gold at the site in 1865, and a formal underground mine reopened as an open-pit in 1987, produced 54,000 to 70,000 oz. of gold a year from 1988-1990.
The site is less than 10 km north of the Mountain rare earth mine, where Dateline has started identifying the source of the mantle derived rocks that are associated with carbonatites.
Riverina in Australia
Ora Banda Mining drill hole RGC24021 at the Riverina-Mulline project cut 4.03 metres grading 83.8 grams for a width x grade of 338 from 14.9 metres depth, the company said April 4.
The project, 720 km by road northeast of Perth, Western Australia, is developing an underground operation at Riverina and drilling 20 km east at Sand King for a second potential underground mine. Both would feed the Davyhurst plant 40 km south.
“The Riverina underground mine will soon fulfil the role of the primary producing asset at Davyhurst, taking over from the Siberia open pits,” managing director Luke Creagh said in a release. “We are pleased with the rate of progress and look forward to ramping this up to commercial production expected in the June quarter.”
