FDEM and ERT measurements for archaeological prospections at Nuraghe S'Urachi (West‐Central Sardinia)

Abstract

Nuraghe S'Urachi is a monumental architectural complex in West Central Sardinia that was probably first built in the Bronze Age and remained occupied continuously into the early Roman Imperial period. It has been the object of systematic and largescale archaeological investigations in three different phases since 1948 when the first excavations revealed a complex building within a massive defensive wall and multiple towers. Intermittent fieldwork between the 1980s and 2005 subsequently showed that the central nuraghe might comprise up to five principal towers. In 2013, a new collaborative research project, sponsored by Brown University and the Municipality of San Vero Milis, brought together a multidisciplinary research project to investigate this important archaeological site. In this framework, multi-frequency and multi-coil electromagnetic measurements (FDEM) and Electrical resistivity tomography (ERT) were carried out in 2018, 2019, and 2020, over and close to the nuraghe towers, to gain a better understanding of the inner part of the main structure and to investigate the surrounding area that was intensively settled in Phoenician and Punic times. The preliminary results of the geophysical measurements provide new and interesting evidence that supports new hypotheses and suggests possible future archaeological and geophysical strategies to investigate the unexcavated part of the archaeological site of S'Urachi.

Non-Invasive Survey Techniques to Study Nuragic Archaeological Sites: The Nanni Arrù Case Study (Sardinia, Italy)

“…The integration of data from satellite observation, drone-deployed sensors, and geophysical methods has been carried out in some archaeological studies [19][20][21][22][23][24].…”

Forward Electromagnetic Induction Modelling in a Multilayered Half-Space: An Open-Source Software Tool

“…Electromagnetic induction (EMI) methods are proximal and remote sensing methods, among the most popular in near-surface geophysics investigation. They have been successfully used, often in combination with other geophysical techniques, in many areas spanning from environmental and hydro-geophysical investigations [1][2][3][4] to the characterization and monitoring of dismissed municipal and industrial solid waste landfills [5][6][7][8], from the quantitative evaluation of soil salinity and its spatial distribution [9][10][11][12][13] to soil water content monitoring [14][15][16][17][18], from sedimentology and soil studies [19][20][21][22] to archaeology [23][24][25][26][27], just to name a few.…”

Geomagnetic and FDEM Methods in the Roman Archaeological Site of Bocca Delle Menate (Comacchio, Italy)

“…Therefore, the geophysical methodologies are so crucial for those old archaeological sites, which were excavated decades ago, both to highlight them again and to detect new buried remains. A great variety of geophysical methods are currently available for specific archaeological demands, and the techniques that are most useful in this field are: geomagnetic (MAG) investigation, ground penetrating radar (GPR), electrical resistivity (ER), and electromagnetic (EM) acquisitions [1][2][3][4][5][6][7][8][9][10]. The geomagnetic technique is a passive method and, therefore, it is based on measurements of the Earth's magnetic field with sensitivity on the order of nanoTeslas (nTs).…”

“…In most cases, MAG and GPR yield the best results due to the significance of the corresponding geophysical parameters and the high resolution of the advanced equipment available today. These methods are able to investigate, at different resolutions, the buried structures in the first meters of the subsoil, and there are several papers that reported their success [1][2][3][4][5][6][7][8][9][10]. On the contrary, even if the EM and geoelectrical (DC) methods are applied to detect buried structures, they are most useful to define the geological and geomorphological surrounding context [6,7,[10][11][12].…”

“…These methods are able to investigate, at different resolutions, the buried structures in the first meters of the subsoil, and there are several papers that reported their success [1][2][3][4][5][6][7][8][9][10]. On the contrary, even if the EM and geoelectrical (DC) methods are applied to detect buried structures, they are most useful to define the geological and geomorphological surrounding context [6,7,[10][11][12]. Geomagnetometry and GPR offer a fast and cheaper way to survey the archaeological sites, thanks to the possibility to investigate large areas [13][14][15].…”