Antofagasta options Alaska copper project
Agrees to invest $30M to explore Tanacross over eight years North of 60 Mining News - July 20, 2022
Last updated 7/28/2022 at 1:45pm
Chilean copper miner Antofagasta PLC has entered into an option agreement with Kenorland Minerals Ltd. to earn a 70% interest in Tanacross by investing US$30 million in exploration over eight years and publishing an NI 43-101-compliant preliminary economic assessment on the porphyry copper-gold project in eastern Alaska.
"We're very excited to be working with Antofagasta on the Tanacross Project," said Kenorland Minerals CEO Zach Flood. "The property, which covers numerous mineralised systems and target areas, warrants significant exploration to unlock the discovery potential that we believe exists."
Five decades in the making
Lying alongside the Alaska-Yukon border, the 113,400-acre Kenorland property hosts world-class porphyry copper-gold deposit potential.
"Geologically speaking, the property has the right ingredients to host a significant mineral deposit – it sits on the intersection of two major crustal structures, has a large geophysical and geochemical expression, and the mineralized intrusions are the right age," Flood told Mining News in 2018.
One of the major crustal structures at Tanacross, the Big Creek Fault, is also a major feature of Western Copper and Gold's world-class Casino porphyry deposit in the Yukon.
Situated about 90 miles southeast of Tanacross, Casino hosts 1.22 billion metric tons of reserves containing 5.1 billion pounds of copper, 8.5 million ounces of gold, 64.9 million oz silver, and 572 million lb of molybdenum.
Like Casino, Tanacross is located at the intersection of a second major structure intersecting the Big Creek fault.
Since the discovery of the East Taurus deposit in 1971, 17,076 meters of drilling in 67 holes have been completed at Tanacross.
Highlights from historical drilling include:
• 175 meters averaging 0.31% copper, 0.1 grams per metric ton gold, and 0.032% molybdenum in hole 96DDH030.
• 208.5 meters averaging 0.23% copper, 0.14 g/t gold, and 0.32% molybdenum in hole 96DDH032.
• 232.6 meters averaging 0.31% copper, 0.25 g/t gold, and 0.036% molybdenum in hole 08DDH040.
The most recent drilling was completed in 2019 by Freeport McMoRan, which optioned the property from Kenorland. Highlights from Freeport drilling include:
• 285 meters averaging 0.23% copper, 0.16 g/t gold, 1.08 g/t silver, and 0.036% molybdenum in hole 19ETD050.
• 412.4 meters averaging 0.11% copper, 0.12 g/t gold, 1.17 g/t silver, and 0.015% molybdenum in hole 19ETD051.
In 2021, Kenorland completed detailed soil sampling and mapping carried out over the East Taurus, West Taurus, South Taurus, and Big Creek target areas. High-resolution drone magnetic surveys were flown over the same area, and a Titan high-powered induced polarization and magnetotelluric survey was completed at South Taurus.
The Antofagasta option
The culmination of this work has drawn the interest of Antofagasta.
To earn a 70% joint venture interest in Tanacross, Antofagasta Minerals S.A, a subsidiary of Antofagasta, has agreed to pay Kenorland an initial US$1 million cash payment and spend US$30 million on exploration over eight years, including a minimum of US$1 million in the first year. Upon completion of its work commitment and delivering a PEA that outlines the economic and engineering parameters of developing a mine at Tanacross, the Chilean copper miner will pay Kenorland an additional US$4 million.
During the option period, Antofagasta will fund all exploration and Kenorland will be the initial operator.
"We look forward to getting back on the ground as soon as possible to begin work which will lead towards drill-target definition," said Flood.