Abstract
Tell Dibgou, northeastern Nile Delta (Egypt), is a typical type of complex archaeological site that contains ruins from different chronological periods (Pharaonic, Byzantine, Greece-Roman and Islamic), as evidenced by the findings of pottery kilns, pottery shards, fired brick and colored glass. This study aims to image the topmost archaeological layer of Islamic architecture using electrical resistivity tomography and land-based magnetic surveys. Two nearby areas in the northern part of Tell Dibgou were investigated; the first was surveyed using resistivity tomography and magnetics, and the second used total-field and vertical magnetic gradients. Several electrode arrays (dipole-dipole, Wenner Beta, Wenner Schlumberger and pole-dipole) were tested to select the one that provides better resolution. Two inversion schemes were applied where the smoothness-constrained inversion smeared and blurred the archaeological boundaries, and the robust inversion produced models with well-defined and sharp edges. The vertical extent of the topmost archaeological layer of Islamic settlers was imaged using the electrical resistivity tomography; however, the presence of slag debris, collapsed bricks, and pottery shards at shallow depths complicated the discrimination of the closest walls. The interpretation of magnetic data (total and vertical gradients) in terms of depth and geometry was executed using semi-automated techniques such as three-dimensional, Euler deconvolution and tilt angle derivative. The geometry of archaeological targets is interpreted to be closed rooms, water tanks and corridors constructed from fired brick walls filled with clay sediments. The depths yielded from both techniques are comparable and range from >1 m to up to 2 m.