Protocol for lapis lazuli provenance determination: evidence for an Afghan origin of the stones used for ancient carved artefacts kept at the Egyptian Museum of Florence (Italy)

Despite that the Badakhshan Province (Afghanistan) remains the most plausible hypothesis for the lapis lazuli used in antiquity, alternatives proposed in literature are worth to study to confirm or disprove their historical reliability. In this work, a protocol for determining the provenance of lapis lazuli rocks used for carved artefacts is described. Markers for the univocal attribution of the raw material to a source were identified analysing 45 rocks of known provenance (among which 15 georeferenced) from 4 quarry districts. To the best of our knowledge, this reference database is the widest in provenance studies on lapis lazuli. All the markers are recognisable by means of Ion Beam Analysis (IBA) techniques, in particular micro-proton-induced x-ray emission (PIXE) and micro-ionoluminescence (IL). These techniques are non-invasive and applicable in air, allowing to analyse artworks and rocks of practically any shape and dimension without sample preparation.The protocol was applied to determine the provenance of raw material used for carved lapis lazuli artefacts kept at the Egyptian Museum of Florence, the second most important Egyptian museum in Italy, second only to the museum of Turin. The collection in Florence has a great historical value and includes several lapis lazuli pendants, scarabs, small statuettes and amulets ascribable mainly to the first millennium BC. Following the protocol, 11 of these artefacts were analysed by means of IBA techniques. Results ascribe the raw material to the Afghan quarry district.     

Intervention,Facilitation and Self‐development: Strategies and Practices in Forestry Cooperation in Bolivia

Aid encounters in three community forestry endeavours reveal different strategies of development cooperation. The first, intervention, is a unilaterally designed aid strategy where the external intervening party takes the lead, sets goals, draws up plans, etc. The second, facilitation, is a mutually designed strategy of cooperation which focuses on collective action and mutual learning. The third, encouragement of self‐development, is a unilaterally designed strategy where local actors take the lead in development endeavours. This article analyses these three distinctive strategies with reference to social, discursive, political and performative practices found in development cooperation. This provides an integrated framework for assessing local community situations which could guide strategic decisions and promote effective development cooperation.     

Changes in crop cultivation during the last five centuries before the Roman conquest: archaeobotanical investigation in the Clermont-Ferrand basin,Massif Central,France

For several decades, a growing number of protohistoric sites in Auvergne (Massif Central, France)—mostly excavated through preventive archaeology—have been subject to the collection of archaeobotanical analysis. This study presents the archaeobotanical results from ten La Tène sites dating from the last five centuries before the Roman conquest. In addition to providing an inventory of taxa, this paper concerns crops and crop cultivation methods. These results are interpreted in a wider context, dealing with crop husbandry, arable farming, storage and consumption practices. The sites are located in the Limagne plain within a 50-km radius around the city of Clermont-Ferrand. A total of 23,579 carpological remains were identified from 163 sediment samples totalizing a volume of 1096 l. Comparable to other sites in Gaul, the spectrum of cereals and pulses is restricted. Spelt (Triticum spelta), einkorn (Triticum monococcum) and foxtail millet (Setaria italica) are disappearing or becoming rare. A better control of agricultural techniques and increased yields is supposed during the ca. five centuries of the La Tène period. Mixed cultivation is hereby replaced by the sowing of monocrops. At the beginning of this period, farming systems are dominated by a polyculture of cereals and pulses. They become more specialized during the last two centuries before the Roman conquest; diversity of cereals and pulses is decreased.     

Diversification,Intensification and Specialization: Changing Land Use in Western Africa from 1800 BC to AD 1500

Journal of World Prehistory - Many societal and environmental changes occurred between the 2nd millennium BC and the middle of the 2nd millennium AD in western Africa. Key amongst these were...     

Crystallographic and structural transformations of sedimentary chalcedony in flint upon heat treatment

The early occurrence of intentional heat treatment of silica rocks has recently become a key element in the discussion about the cultural modernity of prehistoric populations. Lithic vestiges are the only sources that remain of this process and the understanding of the material’s properties and transformations are essential for reconstructing the conditions and parameters applied during heat treatment. Several models of the structural transformations upon heating have been proposed in the current literature. These models are often contradictory and do not account for the most recent structural and mineralogical data on chalcedony. In order to propose a new model, we elaborated an experimental procedure and applied different techniques involving infrared spectroscopy, solid state NMR, X-ray diffraction and electron microscopy. The results show that the major transformation to happen is the loss of silanole (SiOH) and the creation of new Si-O-Si bonds according to the reaction: Si?OH HO-Si → Si-O-Si + H₂O. This reaction starts between 200 °C and 300 °C and causes an increase in the hardness of the rocks. The maximal annealing temperature and the ramp rate are the functions of the ability of the structure to evacuate newly created H₂O and depend on the size of the specimen and the volume of its porosity. These results also show that the annealing duration at maximum temperature can be relatively short (<50 min) for a sufficiently large amount of transformation to be accomplished.