Application of Surface Resistivity Methods to the Detection of Salt-Water Intrusion in Shippegan, New Brunswick
H. LAZREG, Inland Waters Branch, Hydrologic Sciences Division, Department of the Environment, Ottawa, Canada
This paper presents an evaluation of surface resistivity techniques as a tool for delineating salt-water intrusion in Shippegan, N.B. The study consisted of resistivity profiling, resistivity soundings and a limited number of induced polarization soundings in selected areas in the Province of New Brunwick. The results from resistivity profiling indicate that when seawater intrusion occurs in a sandstone formation the resistivity contrast is sufficiently large to allow a precise delineation of the intl\usion. A formula is then derived to convert resistivity values to chloride concentration in the "cone of intrusion". The results from resistivity soundings showed that shaly formations may have resistivities as low as seawater-contaminated sandstone. An indeterminacy has resulted from this resistivity overlap. A limited number of IP soundings were performed in an effort to resolve it. The results showed that IP can be of appreciable help in resistivity interpretation.
Aquifer, groundwater, resistivity, sandstone, shale, formation, Groundwater, Groundwaters, Intrusions, Resistivity, Sandstone, Shale, Shales, Water, Waters