Structural, Kinematic, and Hydrothermal Fluid Investigation of the Gold-Bearing Murray Shear Zone, northeastern Minnesota

Abstract

Gold mineralization within Archean granite greenstone terrains of northeastern Minnesota continues to be enigmatic despite its known association to shear zones, faults, and folds. As products of deformational events shear zones, faults, and folds localize fluid transportation and ultimately gold mineralization. Their kinematic history and structural architecture contain important clues about the genesis, characteristics, and mechanics of ore-bearing fluids. The Murray Shear Zone of northeastern Minnesota hosts subeconomic gold in a unique structural setting. Evidence exists in support of shear zone-hosted gold mineralization that coincides with established models for well-known and profitable gold deposits of other Archean greenstone terrains. This thesis presents a structural, kinematic, and hydrothermal fluid investigation of the Murray Shear Zone with implications for gold mineralization. Field and laboratory research such as structural mapping, analysis of thin sections for microstructures and deformation mechanisms, and geochemical study was conducted to provide a comprehensive look at gold mineralization processes of the Murray Shear Zone.