The comparison and application of silicone casting material for trauma analysis on well preserved archaeological skeletal remains

The analysis of tool marks in bone is important in both archaeological and forensic examination to enhance our knowledge of the funerary context. Some tool mark characteristics are difficult to identify macroscopically and often additional imaging equipment is needed. Microscopic analysis of trauma has proven to be beneficial in determining individual characteristics of tool marks. However, due to the sample size restrictions or pre-analysis treatment of the sample, microscopy is not commonly used to analyse trauma on archaeological skeletal remains. The creation of casts of the tool marks is an obvious solution, but often the perceived risk of damaging the skeletal remains deters its use. Casting materials are used by many forensic scientists but there is little mention within the literature on the effectiveness of using these products to record tool marks on archaeological skeletal remains. This research used three commonly used silicone-based casting products, Xantopren L blue, Mikrosil, and Alec Tiranti RTV putty silicone, to record tool marks in modern and archaeological bones. Forty-five casts were analysed to identify which product is the least destructive and most effective in recovering tool characteristics from the skeletal remains. The results show that all of the products tested were able to replicate blade trauma and allowed the affected area to be analysed in greater detail. A comparison of the application and the effect of the products on bone revealed that Alec Tiranti putty was the best product to use on well preserved archaeological remains. Although the creation of casts using Alec Tiranti putty took longer in comparison to the other products, it did not damage the cortex of archaeological bone whereas this was not the case with Xantopren and Mikrosil. To demonstrate these results on human skeletal remains, Alec Tiranti putty was used to cast peri-mortem modification on an Iron Age cranium from Peterborough, Cambridgeshire. These casts were non-destructive and allowed for previously unidentified tool marks to be discovered.