Relationship of gravity, magnetic, and self-potential anomalies and their application to mineral exploration

摘要

When the same source produces gravity, magnetic and SP anomalies, It is shown that 1) The normalized gravity and SP anomalies are identical (except for the sign) when the electric polarization of the source is vertical. 2) The normalized horizontal component of the magnetic anomaly and the horizontal gradient of the SP anomaly are identical (except for the sign) when the directions of electrical polarization and magnetization of the source are the same. These relationships may be used to compute pseudo-SP anomalies from observed gravity/magnetic data and vice versa. These may also be used in the joint inversion of gravity/magnetic and SP anomalies, thus reducing the ambiguity present when interpreting separately. A field example showing the comparison of the pseudo-SP gradient, computed from the magnetic anomaly, with that of the horizontal gradient of the measured SP anomaly shows how anomalies from the same source can be interpreted. The theoretical relationships are thus shown to be useful when interpreting field data.