Near-Surface Geophysical Characterization of Burial Mounds and Traditional Sacred Sites in Aguleri, Anambra State

Aguleri in Anambra State is recognized as a site of profound cultural heritage significance, with burial mounds and traditional sacred sites that contain archaeological deposits of historical and anthropological importance. This study applies near-surface geophysical techniques to characterize the subsurface of burial mounds and sacred sites in Aguleri without the need for invasive excavation. Ground penetrating radar at 250 MHz and magnetic gradient profiling were employed as the primary investigation tools at six selected cultural feature sites. GPR data were collected along parallel profiles spaced 0.5 m apart to generate three-dimensional subsurface images of each mound. Magnetic gradient data were acquired on a 1 m by 1 m grid using a Bartington Grad601 fluxgate gradiometer. GPR reflection profiles reveal stratified internal mound architecture with discrete reflector packages at depths of 0.3 m to 2.5 m, interpreted as successive burial deposit layers. High-amplitude reflectors at depth in three mounds are consistent with large dense objects such as ceramic vessels or metal assemblages. Magnetic anomalies of bipolar character indicate the presence of thermally altered materials (fired clay, burned bone) at shallow depth, consistent with mortuary practices. Joint interpretation of GPR and magnetic data identifies twelve subsurface targets within the six sites as having high archaeological probability. These targets are spatially documented and recommended for controlled excavation in collaboration with Anambra State authorities. This study establishes geophysical practice protocols for heritage site assessment in Anambra State.

Keywords: ground penetrating radar, magnetic gradiometry, burial mound, archaeological heritage, Aguleri