CONTROLLING EFFECTS OF PREEXISTING FRACTURES ON GROUNDWATER FLOW THROUGH CRYSTALLINE ROCKS IN CENTRAL WISCONSIN
Previous work showed that these borehole are hydraulically connected by fractures. Results from our structural analyses show that each of the three bore holes have unique fracture orientation patterns with little or no similarity to each other. Also, the dominant fracture orientations change with depth in all three boreholes. The depths at which the fracture orientation patterns change roughly corresponds with borehole gamma log spikes, implying that orientations of fractures might be controlled by changes in lithology.
We have mathematically determined possible locations where the fractures might intersect underground, thus providing possible pathways for groundwater flow. Drilling wells at those locations might optimize water yield. We plan to create a three dimensional model of the fracture orientations using Arc scene software package to better understand this complex fracture network.