GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 3.2 GNGTS 2024 Results For the data acquired by the EM method, the analysis focused on the quadrature component derived from the highest frequency antenna (250 kHz) to derive the trend of electrical resistvity. The resistvity map obtained reveals the presence of numerous electrical anomalies within the study area (Fig. 2a). These anomalies are characterized by high electrical resistvity values, ranging from 150 to 180 Ohm*m. The primary anomalous sector is characterized by a pronounced alignment of high electrical resistvity values. This sector extends into the central porton of the area, following an almost NNW-SSE directon. Another alignment is observed in the southern boundary of the study area, extends in E-W directon. Moreover, two minor alignments of outliers are observed in the northeastern and northwestern sectors, both of which follow a NW-SE directon. Concerning ERT surveys, resistvity mapping was obtained for each sector. Low resistvity values, ranging from 1.25 to 1.95 log_Res (Ω*m), indicate the presence of loose or poorly consolidated sediments, suggestng the presence of overburden soils. On the other hand, high resistvity values above 1.95 log_Res (Ω*m) are indicatve of more consolidated and cemented rock materials. Anomalies, mainly observed in sectors 1, 2 and 4 (Fig. 2b), consist of abrupt changes in resistvity values from low to high. Sector 3, on the other hand, does not show the presence of anomalies but is entrely characterized by high resistvity values, atributable to the geological characteristcs of the site. All high resistve anomalies show a fairly regular patern and shape. Based on these results, a preliminary archaeological excavaton was performed, limited to the area highlighted in Figure 2b within the green circle (Sector 4). Discussion and Conclusion Electromagnetc (EM) surveys and ERT electrical resistvity tomographies, performed in the Temple Valley, show the presence of several portons characterized by high resistvity values, surrounded by areas with low resistvity values. The high resistvity anomalies suggest the existence of low conductvity bodies, which, considering the lithologies observed in the study area, are probably atributable to Pleistocene calcarenites. In contrast, areas characterized by higher conductvity values may indicate the presence of poorly consolidated flled soils resultng from the erosion process of blue-gray marly clays. Previous studies on archaeological sites, such as those by Di Maio et al. (2016), have shown that similar values of resistvity anomalies may be indicatve of buried rock walls. Based on these evidences, along with the elongated and narrow shape of the alignment of anomalies, as well as their directon and locaton, it is plausible to assume that these anomalies represent remains of walls from buildings.