An X-ray Diffraction (XRD) and X-ray Fluorescence (XRF) investigation in human and animal fossil bones from Holocene to Middle Triassic

We examined by Rietveld refinement of X-ray Diffraction patterns a series of 61 human and animal fossil bones in an age range from present time to Middle Triassic (around 245 Ma). This approach, supplemented by elemental analysis according to X-ray Fluorescence, has permitted to obtain a quantitative evaluation of the mineralogical phases in the specimens, thus allowing to reconstruct the mineralization process involved. Concerning the apatite phase, after adopting a monoclinic geometry for the unit cell, the method permits to determine with fair degree of precision the unit cell volume, which is found to decrease in relatively short geological times as a function of the fluorine substitution process for the hydroxyl group –OH. After excluding the role of a high-temperature fire treatment to the bones, it is found that a certain linear correlation may exist over the geological time scale involved between the age of the specimen and the average crystallite size. This observation permits to use the XRD pattern as an evaluation of the age of the fossil, although the stratigraphic observations, where available, remain as the main reliable source for dating such biomaterials. The uncertainty related to this age estimation may be hardly better than 15–20% in absolute, because of various assumptions involved in the XRD methodology used and in the variability of the burial environment that may be subjected to discontinuous changes over the very long time of deposition.     

A generational attitude: young adults facing the economic crisis in Milan

Abstract

For almost 10 years there has been talk of the economic crisis affecting the European area, with more evident effects in the Mediterranean countries. Yet the expression ‘economic crisis’ has become too wide and blurred to be useful for describing how the current socio-economic conjuncture is affecting different categories of young people in different ways. Precariousness and reduced job opportunities, with their consequences for social mobility, constitute only the more explicit and raw evidence of the lived experience of the crisis among young people. Although families remain the all-solving institution, the consequences of the crisis are diversified according to the economic, cultural and social capital of each individual, to gender and generation position, and to subjective and contextualized perceptions. This article presents research conducted to investigate how young people living in the urban area of Milan locate, react, readapt and reinvent themselves in the present economic context by analysing their aspirations, expectations and practices. We develop a comparative analysis of the main structural bias (gender, education, social class position) in order to shed light on the effects and perceptions of the crisis among young people in the city of Milan.     

Anthropological and physicochemical investigation of the burnt remains of Tomb IX in the ‘Sa Figu’ hypogeal necropolis (Sassari,Italy) – Early Bronze Age

Excavations carried out in Tomb IX of the hypogeic necropolis of ‘Sa Figu’, near the village of Ittiri (Sassari, Italy), supplied burnt human bone remains and pottery unambiguously referred to the Early Bronze Age (characterised by the local culture of ‘Bonnannaro’). Besides the anthropological study, we have investigated and evaluated the possibility of a funerary cremation practice in Sardinian pre‐history, a subject that has previously not been considered from a scientific point of view. Making use of a calibration procedure based on X‐ray diffraction (XRD) line‐broadening analysis, related to the microstructural properties, it was possible to estimate the combustion temperature to which the fragmented bones were subjected. It was found that the studied bones reached temperatures varying from 400°C up to a maximum of 850°C. This spread of values suggested inhomogeneous combustion of the bones, which seems compatible with funerary cremation practices. Copyright © 2007 John Wiley & Sons, Ltd.