Magnetic and electricalresistivity tomography (ERT) surveys were carried out in the area of a Roman militaryinstallationlocatednear the Zeugma archaeologicalsitein southeasternTurkey.Magneticgradiometer surveys were performed in the northern part of this area and covered 8.52 ha; measurements were obtained using a FM-36 fluxgate gradiometer on a 0.5 Â1m grid. The visualized data revealed the general orientation of the Roman military settlement, which appeared as regular structures in the magnetic images.In addition, ERTsurveys were performed in some areas that had shown regular magnetic anomalies. Resistivity data were interpreted using the robust inversion algorithm in two-dimensional and three-dimensional forms. Resistivity tomography studies showed that the archaeological structures lay close to the surface. There was considerable agreement between the results of the magnetic and ERTsurvey methods. Trial trenches were excavated in promising areas to test the geophysical results. A range of distinctive elements of military settlement, such as walls, pipes, roads, foundations and also metallic objects (a large assemblage of Roman military helmets and armour) were discovered during the excavations.

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A large‐scale resistivity imaging survey was performed in the acropolis area of Archaic Cnidos, south‐western Turkey. This survey was a part of the geophysical studies conducted between 1999 and 2004. Two‐dimensional resistivity data were acquired along a number of parallel lines using a pole–pole array. The data was processed using a 3D inversion algorithm based on a robust technique. We also applied shaded‐relief processing to enhance the representation of the images of apparent‐resistivity data and inversion results. In addition, the inverted resistivity data were visualized by a volumetric representation technique to display both the horizontal and the vertical extents of the archaeological structures. The inversion results revealed that a rectangular gridding pattern and a dense structuring existed in the depth range 0.35–1.5 m in the acropolis. Moreover, the bedrock was the base of the archaeological structures in the area. Based on the resistivity survey, four test excavations were carried out in various localities in the acropolis in 2004. These excavations yielded results supporting those obtained by the resistivity inversion. This indicated that large‐scale 3D resistivity imaging can be a useful tool in archaeological prospection.

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A shallow aquifer system was investigated with 2D electrical resistivity tomography (ERT) to determine the hydrogeological setting of the Balıklı Lake region, Şanlıurfa, Turkey. Many spring waters are found in the study area where groundwater flow paths merge and reach the surface. A recreation complex was planned near the Balıklı Lake by the Municipality of Şanlıurfa. Therefore, an ERT survey was carried out to reveal the subsurface characterization, particularly to investigate the possible shallow aquifer system beneath the recreation area. Consequently, 2D resistivity data along thirteen profiles were acquired in the study area and the data were inverted by a tomographic inversion technique. The conductive layers in the ERT results indicated a shallow aquifer zone probably related to a karstic environment. The high conductivity observed in this layer might be caused by pollution resulting from the industrial and domestic wastes of the residential areas. The high resistive bottom layer was considered to be the basement in the study area. The geometry of the shallow aquifer environment was confirmed by slicing maps obtained from the ERT data. To build the conceptual geological model, a 2D forward resistivity modelling study was also achieved after the inversion studies. The inversion parameters and borehole result underlie the background of the forward model. Field and synthetic data were compared to each other and tested in means of calculation of the misfits to determine the reliability of these models.

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