Electrical Resistivity Tomography for the Modelling of Cultural Deposits and Geomophological Landscapes at Neolithic Sites: a Case Study from Southeastern Hungary

Abstract

A large-scale electrical resistivity tomography (ERT) survey was undertaken around the Neolithic tell of SzeghalomKovácshalom in southeast Hungary, covering an area of almost 6 ha. High-resolution ERT data were collected along 28 uniformly distributed transects of variable length using the roll-along technique. A recently presented two-dimensional fast non-linear resistivity inversion algorithm was used to invert the ERT data and recover the true subsurface resistivity distribution along the specific cross-sections. The algorithm calculates and stores in an efficient manner the part of the Jacobian matrix that is actually important within the inversion procedure, thus rendering it almost 4.8 times faster than the algorithm that calculates the complete Jacobian matrix, without losing quality. The algorithm was further modified to account for any non-standard electrode configuration. A recently established iterative algorithm for sparse least squares problems (LSMR) was incorporated for the first time into the algorithm to solve the inverse resistivity problem. The effectiveness and robustness of the LSMR solver was highlighted through the processing of all the ERT lines. The processing and evaluation of the ERT data made it possible to map the thickness of the anthropogenic layer below the surface of the tell, to outline the horizontal and vertical dimensions of the palaeochannel adjacent to the tell, and to determine the general stratigraphy of geological layers up to 10 m below the ground surface. The ERT results also were used to update an older topographic map of the site showing the course of the palaeochannel around the tell. A synthetic model verified and enhanced the conclusions based on the field data. This study illustrates the added value that a systematic ERT survey can provide in reconstructing the ancient fluvial geomorphology of a microregion as well as the depth and horizontal extent of deposits associated with human habitation at archaeological sites.

3D Reconstruction of Buried Structures from Magnetic, Electromagnetic and ERT Data: Example from the Archaeological Site of Phaistos (Crete, Greece)

“…Subsequent inversion processing of the observed apparent data then allows us to retrieve the true resistivity distribution of the underground that is useful to define the geometry and nature of subsurface targets, such as the soil/bedrock interface, strata thickness, or depth and width of anthropical structures. Although several wide‐range ERT applications have been proposed (Drahor et al ., ; Drahor et al ., ; Papadopoulos et al ., ), the ERT technique is generally used for the production of highly detailed pictures of specific features in smaller areas, to reduce the cost of the geophysical survey.…”

How efficient is an integrative approach in archaeological geophysics? Comparative case studies from Neolithic settlements in Thessaly (Central Greece)

“…Previous results provide good data, especially for multi‐layered sites representing the last occupation of the settlement (Casana, Herrmann, and Fogel ; Novo, Vincent, and Levy ). On the other hand, the low contrast of electrical properties within this melting pot of structures and archaeological layers limits the effectiveness of electrical tomography, although it does provide certain advantages for understanding the geomorphological context (Papadopoulos et al ) and for identifying the global orientation and general stratigraphy of some sites (Berge and Drahor ). Magnetics are often successful in showing the full extent of a settlement.…”

Electrical Resistivity Tomography with Angular Separation for Characterization of Burial Mounds in Southern China

“…; Papadopoulos et al . ). Burial mounds can offer opportunities for the reconstruction of ancient lives and customs (Forte and Pipan ), but they are challenging targets for geophysical exploration in archaeology.…”