| Abstract |
Self potential (SP) determinations on recently surveyed volcanic areas of geothermal interest, as well as result on previously reported field, suggest the SP anomalies consist of a positive portion, enclosed in and area of negative polarity. The usual dipolar anomalies are described as two separate areas of different polarity, neither of which enclose the other one. The positive portion, in both cases, correspond t the area in which hot, uprising fluids arrive at or near the surface, while the negative portion corresponds to downward motion of cooler fluids. The term superposed dipolar is introduced to emphasize the structural different with the usual dipolar anomalies. |