Seabridge drills KSM-like target at Iskut
Tests for porphyry copper-gold below the Quart Rise lithocap North of 60 Mining News – July 17, 2020
Last updated 7/16/2020 at 4:49pm
Seabridge Gold Inc. July 16 announced the start of a roughly 8,000-meter drill program targeting a gold-copper porphyry mineral system below the Quartz Rise lithocap on the company's Iskut property in British Columbia's Golden Triangle.
Located about 30 kilometers (19 miles) west of Seabridge's world-class KSM gold-copper project, Iskut is home to the historical high-grade Johnny Mountain gold-silver-copper mine. Three years of work at Quartz Rise, including two small drill campaigns, have isolated a promising source of the Quartz Rise lithocap to the southeast of Johnny Mountain. Lithocaps are typically formed above a deeper porphyry system, which is the larger gold-copper deposit Seabridge is seeking at Iskut.
"Seabridge acquired the large land package at Iskut because we saw clear evidence of a porphyry system with many of the characteristics of our giant KSM project in rocks of the same age. We are excited that we now have the opportunity to test these ideas," said Seabridge Gold Chairman and CEO Rudi Fronk.
Seabridge says an intense induced polarization (IP) geophysical anomaly found in close association with magnetic anomalies have helped to define the target location below and west of the well-developed lithocap. The company plans to complete up to 8,000 meters of core drilling to evaluate about 750 meters of strike and more than 800 meters of vertical projection evident in the geophysical data.
The strategy at Quartz Rise will follow the successful formula Seabridge used to discover Deep Kerr, a zone on the KSM property that hosts 1.9 billion tons of inferred resource averaging 0.31 grams per metric tons gold and 0.41% copper.
Drill holes are designed to cut across the IP anomaly and a distinct magnetic feature at Quartz Rise that encloses the diatreme encountered in previous drilling. A hydrothermal breccia (diatreme) discovered in 2018 was found to contain clasts of porphyry-style vein fragments that confirmed an underlying porphyry source for the lithocap. Holes are planned to penetrate the geophysical anomalies at various elevations along the strike of the features, targeting the likely cradle of the porphyry system. The geophysical footprint of this target trends into an area where glacial erosion has exposed the system vertically over at least 800 meters, making the target amenable to drilling from surface.
Seabridge consulted with First Nations and provincial officials about COVID-19 before deciding to carry out drilling at Iskut this year and have implemented rigorous procedures to minimize the risks associated with the virus.
"We wrestled with the challenge of implementing a drill program this season during the COVID-19 pandemic but our team has worked closely with our Tahltan Nation partners, the BC Health Ministry, suppliers and other exploration companies in the area to develop effective procedures for operating in the current global health crisis," said Fronk. "Crews have new, clearly defined obligations to protect each other against infection and the spread of the virus, all of which have been embraced by our team."
Due to COVID-19, Seabridge has scaled back its 2020 work at KSM.
This year, the company plans to complete about 4,000 meters of geotechnical drilling in ten holes along the proposed route of the Mitchell Treaty Tunnels, a key component of the infrastructure planned for a mine at KSM.
These tunnels would be used to transport ore from the KSM mine to the mill on the opposite side of a mountain. The location of the mill and tailings management facility at some distance from the mines reflects the need for a site with suitable geotechnical characteristics where responsible tailings management can occur. Tunnels are more cost effective and less environmentally impactful than overland transport for the approved multi-decade mine life.
Seabridge had originally planned a larger drill program along the tunnel route this year but has scaled back the program to make it easier to manage novel coronavirus risks.
"Our permit allows us to drill 40 holes, but we have limited this summer's program to only one drill rig and 10 holes to reduce the load on our camp facilities and protect our employees and contractors," said Fronk. "We will be following a very detailed protocol to minimize risks to our workers and local indigenous groups."