www.postersession.com www.postersession.com Three pig legs were buried approximately 20 centimeters (cm) below the surface in the Dartmoor bogs of southern Devon, England for ten months. To understand the bog environmental chemistry and its potential diagenetic effects on buried porcine remains, we applied Portable X-ray Fluorescence Spectroscopy (PXRFS) to the pig bone and burial soil. PXRFS is a non-destructive analytical technique that provides objective, on-site information concerning elemental composition. To assess the potential diagenetic effects of the bog, we analyzed the elemental concentrations of Iron, Lead, Molybdenum, Strontium, Zinc, and Zirconium in the recovered pig bone and burial soil. The significantly higher elemental concentrations of Iron, Lead, Molybdenum, and Zirconium lead to the suggestion that elemental incorporation occurred for those elements in the bog. The low levels of Strontium and Zinc may indicate elemental leaching occurred for those elements in the bog. PXRFS provides valuable information about the interactions between the bog environment and interred remains. That such chemical changes occurred within less than a year, supports a theory that the chemical processes involved in creating a bog body may occur within a short amount of time compared to archaeological timescales. Methods Conclusions The Analysis of Interred Pig Legs in Dartmoor Bog using Portable X-ray Fluorescence Spectroscopy Guinevere Granite, PhD and Robert Palfrey, BA Bibliography Arai 2006; Aufderheide 2003; Bond 2007; Bonizzoni et al. 2011; Borsheim et al 2001; Duraes et al. 2010; Dix & Graham 2000; Ellermann 1917; Evershed 1992; Fiedler et al. 2003; Fiedler et al. 2009; Fiedler & Graw 2003; Forbes et al. 2005; Granite 2012; Granite & Bauerochse 2010a; Freeman et al. 2004; Gill-Frerking & Healy 2011; Granite & Bauerochse 2010b; Granite & Bauerochse 2013; Granite & Bauerochse 2014; Granite & Bauerochse (in press); Hauswirth et al. 1994; Huisman et al 1997; Janaway et al 2003; Janaway et al. 2016; Krachler & Shotyk 2004; Mann et al. 1990; Painter 1991a; Morgan et al. 1983; Painter 1991b; Painter 1998; Painter 2003; Palfrey 2017; Parker & Toots 1970; Price 1989; Katzenberg 1984; Kenna et al. 2011; Lynnerup 2007; Pokines 2009; Polikreti et al. 2011; Shotyk et al. 1990; Silamikele et al. 2010; Somervaille et al. 1989; Stankiewicz et al. 1997; Stokes et al. 2013; Turner & Jans 2008; Weiss et al. 2007; Willey & Heilmann 1987; Wilson et al. 2007; Zaccone et al. 2007; Zaccone et al. 2008; Zoeger et al. 2005; Zoeger et al. 2008. Figure 1 credit: https://www.skyrayinstruments.com/ images/products/genius-1l.jpg Research featured on: Douglas, M. (Producer), & Stein, P. (Director). 2017. Secrets: Bog Bodies [Documentary]. Season 4, Episode 7. Smithsonian Channel. England: Blink Films. Upon locating P1, the surrounding peat was observed to be very water logged as being more compact with minimal geology (Figure 2). The soil surrounding P1 was compact and held the sample together (Figure 3). Upon lifting the specimen, there was a putrescent odour. Once the bony remains of P1 had been cleaned of peat, they were all stained a pale brown. When tissue still remaining on the bone was removed, however, the bone was unstained and white. The bones from both samples recovered still retained sufficient tensile strength to allow excavation and studies. There were sizeable lumps of adipocere found both in the surrounding area and still attached to the bones (Figure 4). This sample had entered advanced decay; the bone and tissues remains were very wet and adipocere had formed (Figure 5). The decision not to carry out further scientific analysis, other than the pH, was due to the presence of adipocere; a state of preservation was achieved. Upon retrieval of P3, we observed that the water level and organic content of the soil was markedly different from that of P1 (Figures 2 and 6). The peat contained higher levels of geological remains from the surrounding area as well as spruce remains than that found with P1. The soil environment was not as organic as P1, with lower levels of spruce remains. After washing the remains of P3, it was noticed that the bones displayed the same pale brown staining but also much darker patches. There were also lumps of adipocere but these were not as significant as the ones display with P1. There was also a much stronger fetid odour than that of P1 (Figure 7). We compared the pig bone elemental concentrations to normal bone and the Dartmoor bog soil elemental levels. The pig bone demonstrated elevated levels in Fe, Mo, Pb, and Zr comparable to those of the bog soil and not similar to normal human bone. The pig bone also showed decreased concentrations of Sr and Zn also comparable to those of the bog soil and not similar to normal pig bone (Table 1). The preliminary study of Turner-Walker & Peacock (2008) involving pig skin burial analysis four years into an eight-year project found similar results. The raw pig skin samples were well-preserved (albeit stained, hard and inflexible) after being buried for four years. Abstract Results British regulations do not allow one to bury human remains for research purposes. Stokes et al. (2013) conducted comparison studies to determine which animal analogue (pork, beef and lamb) are the most precise predictor for human decomposition. The study surmised that all models offered close approximations in decomposition dynamics. Pigs have been used in place of human specimens owing to their physical composition and availability. Three pig legs (P1, P2, and P3) were buried approximately 20 centimeters (cm) under the bog soil surface of a sphagnum blanket bog. This was the maximum depth of burial Dartmoor forestry authorities allowed. Each leg was disarticulated from its pig post-mortem and then prepared to replicate possible burial rituals for Iron-Age bog bodies. The three conditions were raw (P1), roasted (P2), and boiled (P3). Previous research into the significance behind the taphonomic differences between ‘cooked’ and raw enables detection within the archaeological record (Millard 1998). The legs were buried in a Dartmoor blanket bog (National Grid Reference 265450, 83755) for ten months and disinterred on March 2 nd , 2017. When uncovering the pig legs, soil samples were taken from the surrounding bog at 10cm, 20cm, and 30cm intervals. Also, we took a soil sample at the depth of the pig leg burials and a middle phalanx of P1 as a bone sample. We then analyzed all of the collected samples using the PXRFS analyzer. With PXRFS, it is possible to analyze up to 25 different elements simultaneously (Phosphorus (P) to Uranium (U)). For our purposes of analysis, we chose the following elements of interest: Iron (Fe), Molybdenum (Mo), Lead (Pb), Strontium (Sr), Zinc (Zn), and Zirconium (Zr). Using the Skyray Genius 5000 PXRFS analyzer (Figure 1), we conducted 30-second interval readings for each soil and bone sample. We took three separate readings for each sample to obtain an average value range concentration for each element of interest in parts per million (ppm). Introduction The distinctive conditions of Northern Europe raised and blanket bogs can uniquely preserve interred remains for centuries in immaculate condition. These preserved remains are known commonly as bog bodies. The environmental characteristics that allow for such preservation include cold temperatures, strong acidity, anoxia, and nutrient-deficiency. Major contributors to preservation include sphagnum moss, its polysaccharide sphagnan, its product humic acid, and their interactions with various elements, positively and negatively in the bog. Our goal was to ascertain whether contemporary sophisticated techniques, such as Portable X-ray Fluorescence Spectroscopy (PXRFS), could allow us to resolve whether such changes required extended immersion in the bog (millennia versus years or less). PXRFS can provide an understanding of bog environmental chemistry and its potential diagenetic effects on bone and soil. PXRFS helps to determine and quantify the elemental composition of samples by using X-ray excitation. It rapidly identifies and reliably quantifies elements over an extensive concentration range, while neither destroying nor contaminating the sample tested. Additionally, the portability of the PXRFS analyzer allows for on-site testing, providing rapid yet objective, laboratory grade, presumptive analyses on such samples as metal alloys, mineral deposits, soil samples, and bone. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Elements of Interest Average Bone Range Normal Bone Range Average Soil Range Cu 10.16 - 11.9 0 - 19.63 9.93 - 36.18 Fe 1746.35 - 1847.55 100.00 - 300.00 1745.16 - 4428.91 Mo 5.86 - 6.24 < 1.00 3.45 - 6.71 Pb 21.59 - 24.09 0 - 4.00 29.03 - 68.55 Sr 32.08 - 35.08 40.00 - 400.00 4.88 - 18.39 Zn 25.72 - 28.94 164.00 - 256.00 8.08 - 23.30 Zr 71.79 - 73.93 0 - 5.00 175.12 - 238.53 Table 1 Acknowledgements We would like to thank Professor Alan Outram, Dr. Laura Evis, and Dr. John Davey for their assistance on this project. We would also like to thank the Forestry Commission for the Southwest of England for allowing us access to the bog for research purposes. The almost complete disintegration of the buried pig legs leads us to suggest that the shallow depth of the burial allowed oxidation to occur and the remains to decompose. The raw pig leg, which was most similar to the burial conditions of bog bodies, was the only specimen to retain any corporeal remains following ten months of burial. Not only did bog environment destroy most of the buried remains, but it also altered the skeletal composition of the sole remaining middle phalanx recovered dramatically. The PXRFS analyzer provided valuable information for understanding the chemical effects the bog had on that bone. Its results demonstrated that elemental incorporation of Cu, Fe, Mo, and Zr occurred during burial. The PXRFS analyzer also provided the information that Sr and Zn leached from the bones into the surrounding bog environment. Since these chemical changes occurred in less than a year, such findings can support a theory that the chemical processes involved in creating a bog body may occur within a short amount of time compared to archaeological timescales. The observations made within this experiment indicate that mild acidic pH, and anaerobic conditions cause the formation of adipocere. Given the evidence presented in the results section and keeping in mind the limitations imposed upon the experiment in the methodology chapter, preservation within a blanket bog on Dartmoor was achieved in the form of adipocere. Whilst it is difficult to give precise conditions under which preservation is achieved, the results of this experiment are useful for demonstrating the myriad of factors that can influence it. The preservative agents include the role of sphagnum moss, the process of tanning, as well as the acidic, anoxic environmental conditions.