The first use of geophysics in borehole siting in hardrock areas of Africa
The first resistivity soundings applied to borehole siting in Basement areas of Africa were probably measured by Dr. Sydney Shaw in 1933 in Southern Rhodesia, now Zimbabwe. Using a Megger Earth Tester and Wenner array, soundings were measured at a selection of both dry and successful boreholes, and compared. Re-examination of Shaw’s soundings using modern technology shows that the sounding curves are of surprisingly high quality even on today’s standards and indicate a strong relationship between interpreted depth to unfractured granite and drilling results. His survey helped the adoption in Africa of resistivity methods as standard practice in the location of drilling sites for water supply.