The taphonomic and archaeothantological potentials of diagenetic alterations of archaeological bone

Bone is a dynamic substrate in life (Lanyon and Rubin, 1984), after death (Hedges, 2002; Kendall et al., 2018) and even after fossilisation (Saitta et al., 2018). After an organism dies, the bone is transformed by a myriad of physical, chemical and biological processes (Hedges, 2002; Madgwick and Mulville, 2012; Madgwick, 2014; Villagran et al., 2017; Kendall et al., 2018). These transformations may take place during the decomposition of the body itself (Child, 1995; Bell, Skinner and Jones, 1996; White and Booth, 2014; Delannoy et al., 2018), as a result of socio-cultural practices which interfere with processes of decomposition (Jans et al., 2004; Nielsen-Marsh et al., 2007; Madgwick, 2010; White and Booth, 2014) or transform the bone indelibly (e.g. cremation; Hanson and Cain, 2007; Lebon, et al., 2010; Gonçalves, Thompson and Cunha, 2011; Squires et al., 5812011), as well as longer-term interactions between the bone and its depositional environment (Nielsen-Marsh and Hedges, 2000; Hedges, 2002; Reiche et al., 2003; Smith et al., 2007; Turner-Walker and Jans, 2008; Turner-Walker and Peacock, 2008). Strictly speaking, bone diagenesis refers to post-sedimentary taphonomic processes resulting in bone fossilisation or destruction. However, certain pre-sedimentary alterations of bone (i.e. heating) are often referred to as diagenetic, and the extent to which other transformations of bone defined as diagenetic occur pre- or post-deposition is poorly defined; therefore for convenience, all such physico-chemical changes described here are referred to a as diagenetic. Each of these processes transforms the microstructural and chemical properties of a bone in characteristic ways; therefore, ancient bone maintains an imprint of the diagenetic events to which it has been exposed, providing novel taphonomic information from bodies and bones and potential information about funerary practices.