Skip to Main Content


Quantitative interpretation of aeromagnetic anomalies has been based for the most part on the use of physical models in which the direction of magnetization is parallel to that of the earth’s field, al though laboratory results show that this assumption is invalid for many rock units. Magnetic fields have been calculated for inclinations of magnetization significantly different from that of the earth’s present field. The calculations are for a rectangular flat-topped mass with finite and infinite vertical sides and a 75 degree inclination of the earth’s field. Several significant empirical relationships between the physical model and the computed fields have been obtained. For low dips of magnetization, the maximum and minimum points, rather than the points of inflection, mark the edges of the rock masses. The dip of the magnetization vector may be estimated from the ratio between the maximum and minimum anomaly amplitudes. The depth calculation techniques described in Geological Society of America Memoir 47 are based on the assumption of induced polarization, but these same empirical rules can be applied equally well to the total intensity field when remanent magnetization is present. This probably explains the success of the Memoir methods when applied to observed aeromagnetic anomalies over sedimentary basins

You do not currently have access to this chapter.

Figures & Tables





Citing Books via

Close Modal

or Create an Account

Close Modal
Close Modal