A study by thermal treatment and X-ray powder diffraction on burnt fragmented bones from tombs II,IV and IX belonging to the hypogeic necropolis of “Sa Figu” near Ittiri,Sassari (Sardinia,Italy)

In the course of an anthropological investigation of three tombs of the hypogeic necropolis of “Sa Figu” (near the village of Ittiri in North Sardinia, Italy), numerous burnt bone fragments were collected. In particular, from the whole necropolis we selected a tenth of long bones from tomb IV, a small fragment of femur from tomb II and four fragments belonging to tomb IX. The aim of this work is to determine a temperature range to which the bone fragments were heated, in order to assess a funerary cremation which was presumably used at that time to quickly and hygienically eliminate the flashy parts of deceased people rather than a purification rite with fires inside the sepulchres. We attempted to evaluate the range of temperature to which the bones were likely subjected, making a joint use of thermal treatment and powder X-ray diffraction investigations. From our X-ray line broadening results carried out with a modern approach (Rietveld method), it emerged that a group of five fragmented burnt bones (one specimen belonging to tomb IV, the other four from tomb IX) were subjected to a heat treatment in a temperature range from 600 and 750 °C. Conversely another group of bones (belonging to tombs II and IV) turned out to be subjected to temperatures not higher than 250 °C.     

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.