title: Geochemical and mineralogical fingerprints to distinguish the exploited ferruginous mineralisations of Grotta della Monaca (Calabria, Italy).
abstract: This study examines the geochemical and mineralogical variations in the ferruginous mineralisations that crop out within Grotta della Monaca, which is considered to be the most striking and best known example of a prehistoric iron mine-cave from the southern Apennines (Calabria, Italy). Previous archaeological research identified three local and distinct ancient exploitation phases of these ferruginous mineralisations: (1) an Upper Palaeolithic phase; (2) a Late Neolithic phase; and (3) a post-Medieval phase. These materials, which have various forms of complex mineralogical admixtures and range in colour from yellow-orange to red and darker brown shades, mainly consist of iron oxides/hydroxides (essentially goethite and lepidocrocite), which are often mixed with subordinate and variable amounts of other matrix components (carbonates, sulphates, arsenates, silicates and organic matter). Such ferruginous mineralisations generally correspond to geochemically heterogeneous massive dyke/vein/mammillary/stratiform facies that are exposed within the local caves along open fractures and inclined bedding planes and that partially cover cave wall niches/notches/pockets and ceiling cupolas/holes. Selected samples/sub-samples are analysed through a multi-technique approach with a handheld portable X-ray Fluorescence, X-ray Diffraction, micro-Raman and Fourier Transform Infrared spectroscope (both conventional and attenuated total reflection), which is combined with subsequent multivariate statistical analysis of the elemental concentration data. The geochemical and mineralogical results are used to individualise similar compositional clusters. As expected, the identified groups, each of which has very specific geochemical-mineralogical "fingerprints" and spatial distributions, enable us to identify the sampled ferruginous mineralisations. These specific mineral resources can be compared to similar raw materials that are found in other neighbouring archaeological sites, with obvious implications toward understanding local exploitation strategies through time and the exchanges and kinship networks of these materials.
authors: Centre of Studies on Geography and Spatial Planning (CEGOT), Colégio de S. Jerónimo, University of Coimbra, 3004-530 Coimbra, Portugal; Centro Regionale di Speleologia "Enzo dei Medici", Via Lucania 3, 87070 Roseto Capo Spulico, CS, Italy. Electronic address: luca@ci.uc.pt.
authors: Luca Antonio
authors: LA
authors: Dimuccio
authors: Department of Earth Sciences, Faculty of Sciences and Technology, University of Coimbra - Polo II, 3030-790 Coimbra, Portugal.
authors: Nelson
authors: N
authors: Rodrigues
authors: Centro Regionale di Speleologia "Enzo dei Medici", Via Lucania 3, 87070 Roseto Capo Spulico, CS, Italy; Gruppo di Ricerca Speleo-Archeologica, University of Bari, Piazza Umberto, 70121 Bari, Italy.
authors: Felice
authors: F
authors: Larocca
authors: Department of Earth Sciences, Faculty of Sciences and Technology, University of Coimbra - Polo II, 3030-790 Coimbra, Portugal; Marine and Environmental Sciences Centre (MARE), Faculty of Sciences and Technology, University of Coimbra, 3004-517 Coimbra, Portugal.
authors: João
authors: J
authors: Pratas
authors: Unidade de I&D "Química-Física Molecular", Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal.
authors: Ana Margarida
authors: AM
authors: Amado
authors: Unidade de I&D "Química-Física Molecular", Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal.
authors: Luís A E Batista
authors: LAEB
authors: de Carvalho
keywords: Geochemical fingerprints; Grotta della Monaca; Iron oxides/hydroxides; Mineralogical characterisation; Multivariate statistics; Prehistoric exploitation