Isolation of residuals using trend surface analysis to magnetic data

Abstract

Polynomial surfaces of various degrees are fitted to a magnetic data of Awo area, southwestern Nigeria with the aim of isolating the residuals of the area associated with mineralogy. The fourth degree surface correlates better with the magnetic map of the study area. The residualized data were obtained by subtracting the regional values from the relative magnetic (observed) intensity values. With the application of trend surface analysis to the total magnetic field, the presence of tantalite and associate minerals in the area was established. This shows the applicability of the above technique as a good tool in magnetic data interpretation.

Keywords: Isolation, trend surface, polynomial fitting, residuals.

Nigerian Journal of Physics Vol. 18 (2) 2006: pp. 241-250