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The site of Norba is located in the Latium Region, about 90 km S of Rome, Italy. The city is one of the best example of urban town planning, with a regular layout dating back to antiquity. Over the years, many studies and archaeological excavations have brought to light important remains of several buildings, which are still very well preserved. To enhance the knowledge of the unexcavated portions of the archaeological site and to locate the position of the unknown and hypothesized buried structures, extensive geophysical surveys employing the Ground Penetrating Radar (GPR) and Gradiometric methods were planned and conducted between 2017 and 2018. For the measurements, a GPR system SIR3000 (GSSI), equipped with a 400 MHz bistatic antenna with constant offset, was used to survey 27 different sectors close to few excavated areas. Taking into account the environmental conditions of the site and the nature of the buried structures, some areas were surveyed with a spacing interval between parallel profiles of 0.25 m while other areas were investigated with a spatial interval between closed parallel profiles of 0.50 m. Furthermore, fluxgate differential magnetic (Gradiometric) surveys were carried out using the geoscan FM256 in two areas, overlapping the GPR areas. In order to have a better understanding of the subsurface, methods of qualitative and quantitative integration of the results have been employed: maps overlays and RGB color composites (graphical integration), binary data analysis and cluster analysis (discrete data integration), and data sum, data product and principal component analysis (continuous data integration). The results obtained from the geophysical surveys were interpreted together with the archaeologists to define the meaning of the structures identified and to enhance the knowledge of the ancient town's layout and mapping. [ABSTRACT FROM AUTHOR]

The Ansanto Valley (southern Italy) is characterized by vents and boiling mud lakes that emit typical volcanic exhalations (mostly fossil CO2). This fossil dilution spreads over the Ansanto Valley and its impact on local trees is investigated in this study. Six trees at increasing distance from the emitting sources and 2 aliquots of gas were sampled. Dendrochronological analysis was performed on tree cores in order to check the accuracy of the tree-ring sequences; the results indicate no anomalies in the curves of the analyzed trees. d13C and radiocarbon (14C) analyses were performed on the a-cellulose extracted from some selected tree rings. The main aim of d13C analysis was to gain information about the origin of CO2 arising from the source; the results support the hypothesis of a carbonatic origin, with respect to a volcanic origin. 14C analysis was performed to evaluate the influence and to quantify the percentage of fossil dilution characterizing the local atmosphere and affecting the trees at different distances from the source during the years. The results show the presence of a strong fossil dilution affecting the trees, increasing toward the sources (from ~6% at 80 m distance to ~30% at 20 m from the nearest vent) with quite stable values over the examined period. [ABSTRACT FROM AUTHOR]

The Ansanto Valley (southern Italy) is characterized by hydrothermal phenomena, with volcanic gas emissions arising from some vents. In the 1st millennium BC, a sanctuary dedicated to the goddess Mephitis was built but later destroyed by landslides in the valley. During archaeological excavations in the 1950s, many items were found including wooden artifacts, preserved thanks to the imbibition and subsequent mineralization of the wood tissues due to the gas emissions. Radiocarbon dating of these objects is underway at CIRCE (Centre for Isotopic Research on Cultural and Environmental Heritage), in Caserta, Italy. Unfortunately, 2 main problems arise in dating these materials. The first is possible fossil dilution caused by the CO2 emitted from the nearby volcanic vents, which could affect the trees of the valley and also the archaeological materials. In order to determine the magnitude of the fossil dilution in the area, 14C measurements were performed on contemporaneous wood cored from 2 oak trees growing near the vents. 14C values measured in these samples confirmed the presence of a strong fossil dilution in the Ansanto Valley. The second problem is the restoration that the objects underwent during the last century (mostly by using modern organic substances). To investigate suitable pretreatment procedures for removing the restoration materials from the archaeological findings, contemporaneous wood was also analyzed. The wood of trees from the Ansanto Valley and from a distant village (unaffected by the Ansanto fossil dilution) were submitted to the same restoration process applied to the archaeological artifacts, followed by an "artificial weathering" process. Some archaeological materials were also tested for the removal of restoration materials. We subjected the artificially aged trees and the archaeological samples to different chemical processes. Here, we present the results of these processes. Almost all methods turned out to be suitable for the contemporaneous wood, while the results for the archaeological samples remain uncertain. For this reason, more tests are needed, concerning the "artificial weathering," the restoration, and the chemical procedure for removing the consolidation materials. [ABSTRACT FROM AUTHOR]