Interpretation of Sclumberger and magnetotelluric measurements : examples from the Philippines and Iceland

Abstract

Geophysical studies can be a powerful tool to characterize geothermal structures at depth. Considering the rugged Philippine terrain, Schlumberger resistivity surveys are suitable for application in reconnaissance studies of geothermal prospects in terms of portability of equipment and simplicity of survey setup. Thence, characterisation of the resistivity structure at depth within resistivity anomalies defined by a Schlumberger survey can be conducted through the magnetotelluric method. Results of the Schlumberger surveys in Cervantes geothermal prospect in Ilocos Sur, N-Philippines proved the depth limitations of direct current geophysical methods such as the Schlumberger method. However, it could be used to delineate low-resistivity anomalies in the area where future exploration efforts should be concentrated.