A deep resistivity sounding at Rookhope, Northern England

Abstract

Synopsis A method of conducting a resistivity sounding, up to a maximum spacing of 5 kilometres, is described. By conducting measurements, in a symmetrical fashion, about the sounding centre and in two perpendicular directions, it is possible to obtain results which are relatively insensitive to the orientation of the electrode array used and entirely related to the local area around the sounding centre. By choice of the progression of spacing used, it is also possible to express the results in terms of resistivity measures suitable for subsequent interpretation. A resistivity sounding curve, conducted in this manner at Rookhope, shows the existence a highly resistive basement at interpreted depths which are in reasonable accord with the known depth to the Weardale granite in this area.