Alternative models for the interpretation of aeromagnetic data in areas around the

Abstract

Four interpretational models are recognized in areas around the magnetic equator. They are point pole, line of poles, point dipole and line of dipoles. Point pole models are recognized by adjacent circular contours of magnetic high and low, while line of poles models are identified by elliptical contours of magnetic high and low adjacent to each other. When magnetic contours are simply circular or nearly circular, the source is approximated as point dipole and contours of line of dipole model are always elliptical in shape. A decision between dipolar and monopolar model is made using the shape of magnetic signature. When a magnetic signature has completely dominant low, the correct model will be a dipole. While a magnetic high flanked by low is approximated as point pole/line of pole (monopole). Magnetic signature that does not assume any of these shapes is a pointer to remanent magnetization. The four interpretational models have close relationship with half-width of magnetic anomalies and are therefore valuable for depth determination. The four interpretational models have been employed to analyse aeromagnetic data from crystalline basement and sedimentary areas of Nigeria.

Global Journal of Pure and Applied Sciences Volume , No 1 January (2001) pp. 111-116



KEY WORDS:

Equator, Model, Dipole, Remanent, Anomaly.