Scale versus detail in water-rock investigations 2: Field-scale models of fracture networks in mineral deposits

ABSTRACT: Predicting spatial properties of heterogeneous, mineralized rocks is important for many applications. Because each mineral deposit is unique, any analytical framework for studying coupled, water-rock systems must be sufficiently robust to account for variability within and between areas. Rock-water interactions are difficult to model, but a helpful approach to modeling fracture-controlled flow networks in mineralized rocks is to evaluate mineralized fractures and structural geologic systematics in and around specific mineral-deposit types. We propose that the necessary coupling of deformation, chemical transport, and heat transfer in hydrothermal systems sets constraints on fault and fracture systematics that must occur, and these systematics vary according to mineral-deposit type. We propose a set of field-based systematics at different spatial scales for porphyry-style copper and molybdenum deposits and related veins that help in field sampling design and data analysis.