Comparative depth estimation of iron-ore deposit using the Data-Coordinate Interpolation Technique for airborne and ground magnetic survey variation

Abstract

A newly developed quantitative method, Data-Coordinate Interpolation Technique (DCIT) was used by matching the secondary and primary data to correct the variation that exists between airborne and ground magnetic depth-to-basement. The aeromagnetic data within latitude (8.000N, 8.500N) and longitude (4.000E, 4.500E) were acquired and gridded, while the in-situ location are Ajase (8.19520, 8.19720 N), (4.38800 E, 4.39000 E) and Gbede (8.29200 N, 8.29360 N), (4.34620 E, 4.34760 E). Aeromagnetic data were contoured at airborne to ground spacing ratio and data interpolation was done on the contour to produce a set of interpolated data. Quantitative analysis was done using Peter’s Half slope Method (PHSM), Analytic Signal Method (ASM) and Euler Deconvolution Method (EDM) to calculate the depth-to-top of the iron-ore within the basement complex. Results at Ajase for depth for DCIT and ground data were 6.47 ± 2.28 m, 5.79 ± 1.81 m; 5.55 ± 2.90 m, 5.53 ± 1.90 m; and 7.88 ± 1.52 m, 8.75 ± 1.47 m, respectively. At Gbede, the results were 6.16 ± 2.09 m, 5.34 ± 1.50 m; 5.79 ± 2.07 m, 5.66 ± 1.75 m; and 5.95 ± 1.59 m, 5.74 ± 0.88 m, respectively. The average depths at Gbede with respect to DCIT and ground data were 5.97 ± 1.92 m, 5.58 ± 1.38 m and Ajase, 6.63 ± 2.23 m and 6.69 ± 1.73 m, respectively. Comparatively, the variation in the depth estimates for both airborne and ground magnetic data is minimal with DCIT.