Abstract - The world-class Irish Zn-Pb(-Ag) deposits occur within one of the world’s major metallogenic provinces. While
it has been well documented that these orebodies are structurally controlled, exactly how fluids migrated from
source to trap is still poorly understood. Using 3-D modeling techniques, the current study investigates metal
distribution patterns at the Silvermines and Lisheen deposits to gain insights into fluid pathways and structural
controls on mineralization. Distinct points along segmented normal faults are identified as the feeders to
individual orebodies, allowing hot, hydrothermal, metal-bearing fluids to enter host rocks and form orebodies.
These points are characterized by highly localized and elevated Ag, Cu, Co, Ni, and As concentrations as
well as low Zn/Pb ratios, which increase away from the feeders. Metal distributions are initially controlled by
major and minor normal faults and subsequently affected by later oblique-slip dextral and strike-slip faults.
High-tonnage areas without typical feeder signals are interpreted to be structural trap sites, which are distal to
fault-controlled feeder points. This study highlights both the importance of a well-connected plumbing system
for metal-bearing fluids to reach their basinal traps and the control that an evolving structural framework has
on spatial distribution of metals.
Economic Geology, 113, 1455-1477, 2018.