Bones and teeth from archaeological records are direct evidence of past individuals and they represent valuable archives for palaeo-anthropological and palaeoenvironmental studies. However, pristine information may be obliterated by the diagenetic alteration of bone specimens. Thus, defining in detail their preservation state is fundamental to assess the potential of extracting information about the past life of the individual, as well as to investigate the palaeo-environment at the burial site. For this reason, we have selected a set of archaeological samples (petrous bones and tooth roots) of different origin and chronology that have experienced diverse environmental and burial conditions, from arid and semi-arid to temperate regions in a time span from prehistoric to fresh bones. Thus, the selected samples underwent a variety of diagenetic processes, resulting in different types and extent of alteration patterns. Here we have applied a minimally-invasive sampling strategy and an analytical protocol based on Fourier transform infrared spectroscopy (FTIR) in order to ensure the investigation of a statistically significant set of samples. We provide a method to describe and quantify the changes in the physico-chemical properties of both the organic and inorganic constituents of bones, by establishing a set of parameters calculated from the FTIR spectra and evaluating their sensitivity in describing the alteration types and extent in bone specimens. Through FTIR spectral analysis, we have defined the most suitable parameters to effectively describe the alteration degree of bone specimens. Notably, the results have shown that, despite the complexity of multifactorial diagenetic processes, their measurable effects on differently altered bones can be described by a common mechanism. This indicates a progressive loss of collagen which is paralleled to the recrystallization of bioapatite and the loss of structural carbonate, regardless of the origin and chronology of the specimens. Thus, here we propose an FTIR-based model for bone diagenesis of general validity, highlighting that distinct diagenetic processes affecting the archaeological bones have acted according to common alteration mechanisms.

考古记录中的骨骼和牙齿是过去个体的直接证据，它们代表了古人类学和古环境研究的宝贵档案。然而，原始信息可能会因骨标本的成岩改变而消失。因此，详细定义其保存状态对于评估提取有关个体过去生活的信息的潜力以及调查埋葬地点的古环境至关重要。为此，我们选择了一组不同起源和年代的考古样本（岩骨和牙根），这些样本经历了从史前到新鲜的时间跨度，从干旱、半干旱到温带地区的不同环境和埋藏条件。骨头。因此，所选样品经历了各种成岩过程，导致了不同类型和程度的蚀变模式。在这里，我们应用了微创采样策略和基于傅里叶变换红外光谱 (FTIR) 的分析协议，以确保对一组具有统计意义的样本进行调查。我们提供了一种描述和量化骨骼有机和无机成分的物理化学性质变化的方法，通过建立一组根据 FTIR 光谱计算的参数并评估它们在描述骨骼变化类型和程度方面的敏感性标本。通过FTIR光谱分析，我们定义了最合适的参数来有效描述骨标本的蚀变程度。值得注意的是，结果表明，尽管多因素成岩过程很复杂，但它们对不同改变的骨骼的可测量影响可以通过共同的机制来描述。这表明胶原蛋白逐渐损失，与生物磷灰石的重结晶和结构碳酸盐的损失平行，无论标本的来源和年代如何。因此，我们在这里提出了一种基于 FTIR 的具有普遍有效性的骨成岩模型，强调影响考古骨骼的不同成岩过程按照常见的改变机制发挥作用。