Behaviour of High Resistivity Soils in a Tropical Area

The resistivity of superficial soils which are predominantly composed of ancient formations (igneous and metamorphic rocks) is usually very high. This fact is of paramount importance in designing grounding systems. Besides, there is a lack of information on the matter concerning the seasonal behaviour of those soils in countries with tropical or sub-tropical climates. The authors describe the results obtained from about 350 measurements carried out during 8 years in a tropical area, 80% of which formed in the pre-cambrian geolo - gical period, pointing out the particulars of such soils.