Field based NIR analysis for lithic provenance studies in Archaeology. A case study from Montescaglioso (Southern Italy)

The poster presents a first example of field based NIR analysis for determination of archaeological artefacts provenance. The localization of quarries and geologic resources is fundamental to reconstruct trades and economic aspects of past societies. Different analytical methods have been used in archaeology to determine the characterization of lithic materials. These methods are traditionally destructive, requiring samples to analyze in laboratory. The chemical signature of every stone material becomes of extreme importance. A large dataset allows a more accurate historical reconstruction. Within MOBIMA project (mobile imaging in archaeology) we experimented the use of a MicroNIR probe to perform non-destructive analysis directly on the field.
We present a case study from the territory of Montescaglioso (Matera, southern Italy). We performed measurements on a calcarenite (limestone) quarry, in locality Masseria D’Alessio, exploited since the 6th century BC. Artefacts in the same chronology from survey and excavations in the territory were also analyzed. The aim was to determine the spread of calcarenite extracted from the quarry and recognize exploitation and trade patterns.
The instrument used in this study was a MicroNIR 1700 infrared system (JDSU) with a spectral range of 908.1-1676.0 nm and a pixel to pixel interval of 6.2 nm. The probe uses illumination via two integrated vacuum tungsten lamps. We also collected photo documentation and spatial references on a GIS platform. The Near Infrared Information have been completed with typological observations of artefacts and the techniques of stone work.
The data have been processed using Evince software to perform multivariate data analysis: principal component analysis (PCA) and SIMCA models. The chemometric analysis of measurements shows differences among different stone types. A classification according to the geological characteristics was possible.
Measurements on more than 30 artefacts from 4 sites were collected. The identification of the calcarenite extracted from the quarry and its diffusion was possible for different historical periods, from 6th till 3rd century BC.