Salt water intrusion into a coastal water table (shingle) aquifer has occured in Dungeness, England. Chloride ion concentrations as high as 3000 mg/l have been measured. These compare with background values of 40 mg/l. 29 Vertical electrical resistivity soundings using the Wenner array were undertaken to determine the applicability of direct current resistivity as a method for delineating the saline intrusion. Interpretation of the resistivity data show not only a saline zone near the coast resulting from sea water intrusion, but also the presence of a low resistivity layer beneath fresh water bearing shingle throughout the study area. This low resistivity is interpreted as being mainly due to saline waterbearing sands.
A borehole drilled a year after the survey confirmed the presence of saline water beneath a fresh water lens.
- © 1983 The Geological Society