What methods do you use to site a borehole?
Our surveyors use horizontal resistivity profiling (HRP) and horizontal loop electromagnetic (HLEM) traverses for the identification of geological anomalies. Once promising hydro-geological targets have been identified, each target is further evaluated using vertical electrical soundings (VES) to give some indication of the suitability of the target for drilling.
Methods are chosen as appropriate for the hydro-geological setting -- in crystalline basement settings, HRP's are usually more suitable, whereas in sedimentary settings, HLEM is usually more suitable.