Pan American Silver Increases La Colorada Skarn Deposit Mineral Resource Estimate

VANCOUVER - Pan American Silver Corp. reported an updated inferred mineral resource estimate for its La Colorada skarn deposit in Zacatecas, Mexico of 100.4 million tonnes, containing an estimated 141.0 million ounces of silver. The updated mineral resource represents a 38% increase in tonnes and an equivalent increase in silver ounces from the initial inferred mineral resource estimate.  Pan American also reported results of 17 holes drilled in the first half of 2020, all of which contain multiple skarn and breccia intercepts.  

"In the span of only 18 months, we  have been able to discover over 100 million tonnes of polymetallic mineral resources through this exciting skarn deposit at La Colorada. Exploration drilling continues to demonstrate the extent of the mineralized system, which remains open in nearly all directions for resource expansions," said Christopher Emerson, Pan American's Vice President Business Development and Geology. "Drilling over the last six months has further increased our confidence that the La Colorada skarn is a deposit of world-class size and quality. Additional drilling and metallurgical studies, as well as preliminary project engineering, are underway to advance development of this deposit."

A total of 85 diamond drill-holes with a total length of 70,000 meters were used in the geological interpretation and resource estimate. Several old historic drill-holes were included in the modeling. Drilling of the skarn deposit has been completed from both surface and underground drill platforms.

The drill hole samples were prepared by the internal La Colorada mine laboratory, SGS of Durango, Activation Laboratories Ltd (Actlabs) of Zacatecas and Bureau Veritas of Hermosillo.  Pan American implements a quality assurance and quality control ("QAQC") program, including the submission of certified standards, blanks, and duplicate samples to the laboratories.

Both Actlabs and SGS used fire assay with gravimetric finish for gold, and acid digestion with ICP finish for silver, lead, zinc, and copper.  Bureau Veritas used fire assay with gravimetric finish for gold and by acid digestion with ICP finish for silver, lead, zinc, and copper in their Vancouver, Canada laboratory. The La Colorada mine laboratory, which is operated by our employees, used fire assay with gravimetric finish for gold and silver, and acid digestion with atomic absorption finish for lead, zinc, and copper.

The results of the QAQC samples submitted to SGS, Actlabs, Bureau Veritas, and the La Colorada mine laboratory all demonstrate acceptable accuracy and precision. Some standards, blanks and duplicate failures were associated with analysis conducted at the La Colorada mine laboratory, as reported in the news releases dated October 23, 2018 and May 8, 2019. These failed batches were re-submitted to SGS or Actlabs for analysis and results were verified. SGS, Actlabs and Bureau Veritas are independent from Pan American.