PDAC: ‘Boots on the ground’ at Silicon unlocked huge Discovery of the Year

Geologist Paul Bartos recalled exactly 10 years ago Wednesday when he and other AngloGold Ashanti (NYSE: AU) employees met with Renaissance Gold staff to discuss early-stage projects in southern Nevada.

Bartos, who delivered the PDAC Thayer Lindsley Discovery of the Year Award keynote address, had already been involved in big finds over his career. His past included the San Bartolome silver mine in Bolivia and the Chert Cliffs Carlin gold deposit in Nevada when he confronted the “oddball” geology of Silicon, 200 km from Las Vegas.

“How we actually found it? Boots on the ground, detailed old school field mapping of structure and alteration,” he told the audience. “Many of these people are core loggers, and to me, core loggers are the hidden heroes of our business.”

That meeting with Renaissance in 2016 would eventually lead to one of the largest gold discoveries in the United States in recent decades.  A resource last year outlined 88 million tonnes grading 1.75 grams gold per tonne and 2.75 grams silver for about 5 million oz. gold and 7.8 million oz. silver in probable reserves.

‘Over-explored’ Nevada

Callinan Royalties, which helped fund Renaissance’s early exploration work, also shared in the award as this year’s Prospectors and Developers Association of Canada convention ended in Toronto.

When AngloGold first considered Silicon, management regarded Nevada as a “diversion” and a jurisdiction that was very mature but over explored, Bartos said. 

“But I was allowed to pursue opportunities, albeit with no budget, no staff, no field vehicle. One could reasonably infer expectations were perhaps not excessive,” he said.

Renaissance, which later merged with Evrim Resources, had conducted early exploration at the Silicon site, including Landsat satellite imagery mapping.

Landsat eye view

After Bartos had been able to assemble a team, they used Renaissance’s Landsat data to do more mapping, economic modelling and drilling at the site under an option deal AngloGold signed with Renaissance in 2017.

Bartos said that Silicon had been overlooked in past exploration because of its geologic properties didn’t fit prevailing dogmas.

“It had to be tested,” he said. “[There was] the intensity of the alteration and I had every confidence we’d find something interesting.”