Delineation of Egyptian mud bricks using magnetic gradiometer techniques

A near-surface magnetic gradiometer survey of a site at Hawara, Fayoum city is used to delineate archaeological features made by mud bricks at shallow depths in the northeast of the pyramid of Amenemhat III. Magnetic survey data were processed to a precise forward processing sequence, including clipping, de-sloping, removing stripes and edge discontinuities, de-spiking, filtering, interpolating, and finally detecting statistically significant results. The processed magnetic data indicate high amplitude anomalies in the northeastern part of the pyramid Amenemhat III, suggesting the presence of shallow cemeteries of mud brick walls. Low pass filtering of the vertical gradient data helped reveal the relatively deep mud brick features in the generally shallow section. These features were isolated using a statistical detection technique, and verified by the correlation with the surrounding mud brick discoveries. This required the analysis of the magnetic behavior of exposed mud bricks and man-made objects for comparison with the magnetic signature of buried material. These were then matched with the vertical magnetic gradients of the exposed mud brick features from here and three other Egyptian localities. They are mostly the extension of the 12th Dynasty cemeteries, which exist in the western and southwestern parts of the study area.