Geology

The Mallay Mine hosts a high-grade silver-lead-zinc vein system with epithermal characteristics. Mineralization is structurally controlled, occurring within steeply dipping quartz-sulfide veins that cut Mesozoic-aged quartzites and limestones.

Ore zones consist of banded and brecciated quartz veins with sphalerite, galena, and silver-bearing sulfosalts, with gangue minerals including barite and calcite. Historical development focused on discrete high-grade shoots accessed through underground mining.

Mineralization is typically hosted along fault zones, with multiple parallel and sub-parallel structures identified throughout the mine area. Alteration includes silicification, chlorite, and minor argillic overprint proximal to vein zones. These features are consistent with intermediate- to high-sulfidation epithermal systems found throughout the central Andes.

Note: The geological model and historical resource data for Mallay are based on JORC standards and have not been verified under NI 43-101. A Qualified Person has not completed sufficient work to classify the historical estimates as current mineral resources, and Excellon is not treating the historical estimates as current.