Fig. 5. Details of the Borrow Pit. (A) Vertical outcrop face of the southern Borrow Pit site and (B) corresponding fracture trace maps underlying test pit sites of dye and infiltration tests at the Borrow Pit site (Fedors et al., 2001). Persistent fracture network lies within the immediate hanging wall of two macroscopic faults. Two major high-angle sets are characterized by thin discrete surfaces filled with calcite or wider distributed zones of hairline fractures stained with iron oxides. Slickenlines were observed on several fracture surfaces. Hydrologic tracer tests (Pits 1 and 2) by Fedors et al. (2001) suggest fractures enhance matrix flow vertically by constraining lateral flow. (C) North-northeast view of the floor of the Borrow Pit (shown in Fig. 4b) and its vertical faces. (D) Vertical fault at the northwest corner of the Borrow Pit site. Smooth mineralized fault surface consists of calcite and has nearly pure dip-slip slickenlines.