UPSTATE SPRINGS PROJECT, PART II: SPRING WATER CHEMISTRY AS AN INDICATOR OF FAULT, FRACTURE, AND JOINT NETWORK CONTROL OF GROUNDWATER FLOW IN A CRYSTALLINE TERRAIN, SLATER AND DACUSVILLE QUADRANGLES, GREENVILLE AND PICKENS COUNTIES, SOUTH CAROLINA

Faults, fractures, and systematic joint sets can act as conduits or as barriers to fluid flow. This study focused on water chemistry of selected springs to determine spatial trends of chemical parameters and their potential relation to breakage networks in crystalline bedrock. We hypothesized that the groundwater discharge at springs heading first order streams would show some chemical patterns with the same or similar directionality as steep bedrock faults, fractures, and joints, which regionally strike NW, NE, and E-W. All springs we sampled were underlain by uniform quartzo-feldspathic bedrock in order to eliminate chemical variability resulting from primary bedrock compositional differences.

From an inventory of three hundred springs discovered locally by our companion study (Upstate Springs Project, Part I), we took field measurements of pH, temperature, dissolved oxygen, elevation, and conductivity at over 40 selected springs. In addition, we collected water samples to analyze in the laboratory for ion levels, nitrogen content, carbon content, and alkalinity. Specifically, each sample was analyzed for HCO₃^- concentration, dissolved organic carbon, total dissolved nitrogen, and NH₄⁺ as well as the cations Na⁺, K⁺, Ca⁺², Mg⁺², Si⁺⁴, and iron, and the anions F^-, Cl^-, NO₂^-, Br^-, PO₄^3-, NO₃^-, and SO₄^2-. We analyzed the raw chemical data for any noteworthy correlations and spatial patterns. All data was plotted geospatially to determine chemical trends, and these were compared with known fault, fracture, and joint strikes. We have seen well-defined map trends shown by a number of our chemical parameters. Our initial interpretations show, for example, that the Ca²⁺ concentrations appear to show preferred NW trends; the SO₄^2- concentrations however show NE trends. Some compounds appear to show concentrations aligned spatially along both trends, for example dissolved organic carbon. We conclude that several analyzed chemical trends of selected spring waters are consistent with and produced by flow along the breakage networks present in the crystalline bedrock. This study substantiates the conclusion of our companion study that springs owe their distribution to flow channeled along regional breakage networks.