Borehole Flows, Hydraulic Heads, and Fracture-Zone Connection in The Potsdam Sandstone at The Altona Flat Rock Research Site in Northern New York

Numerous borehole-geophysical methods are available for the characterization of fractures penetrated by boreholes but relatively few of these methods help to characterize the connections between fractures in the rock surrounding boreholes. Unfortunately, most studies in fracture-rock hydrology conclude that the characteristics of connections between locally transmissive fractures have a greater influence over aquifer-scale permeability than the local aperture of individual fractures (Long and others, 1996; LeBorgne and others, 1996; Shapiro and others, 2007). The study described here focused on the application of borehole-flow methods in the characterization of possible hydraulic connections between fracture zones penetrated by open bedrock boreholes.