Stable isotope analysis of carbon (C), nitrogen (N), hydrogen (H), and oxygen (O) of archaeological bone has become an increasingly common research method for interpreting human behavior in the past. However, diagenesis of skeletal material can invalidate stable isotope ratios, thereby compromising interpretations. We examine patterns of bone diagenesis using infrared spectroscopy of bone bioapatite samples in relation to indicators of organic preservation quality indicators. We assess crystallinity, an indicator of bioapatite preservation, using the infrared splitting factor (IR-SF) and carbonate content (carbonate to phosphate ratio, C/P) calculated from infrared spectra. We then test the assumption that if the organic fraction of bone is preserved, the mineral fraction will also be unaffected by postmortem chemical alteration. We analyzed 454 bone bioapatite and extracted bone organic sample pairs from modern, historic, and prehistoric humans. Consistent with previous studies, we observed a strong, statistically significant negative linear relationship between IR-SF and C/P (r = −0.855, p < 0.001). Modern bone bioapatite samples unaltered by diagenesis have low IR-SF and high C/P values. There was no significant association between the collagen yield or atomic C:N ratio and IR-SF or C/P values. The range of variation in IR-SF and C/P values for samples with organic yields between 0 and >20 percent spanned the range of modern bone bioapatite unaltered by diagenesis as well as bone bioapatite significantly affected by diagenesis. The lack of predictive patterning between bone inorganic and organic diagenesis suggests that the depositional context and site formation history play critical and independent roles in the organic and mineral fraction of bone. Thus, the preservation of the organic fraction of bone is not predictive of the preservation of the inorganic fraction (e.g., bioapatite).

考古骨骼中碳（C）、氮（N）、氢（H）和氧（O）的稳定同位素分析已成为过去解释人类行为的越来越常见的研究方法。然而，骨骼物质的成岩作用可能会使稳定同位素比率失效，从而影响解释。我们使用骨生物磷灰石样品的红外光谱与有机保存质量指标的关系来检查骨成岩作用的模式。我们使用红外分裂因子 (IR-SF) 和根据红外光谱计算的碳酸盐含量（碳酸盐与磷酸盐的比率，C/P）来评估结晶度，这是生物磷灰石保存的指标。然后我们测试这样一个假设：如果骨骼的有机部分被保留，矿物质部分也将不受死后化学变化的影响。我们分析了 454 个骨骼生物磷灰石，并从现代、历史和史前人类中提取了骨骼有机样本对。与之前的研究一致，我们观察到 IR-SF 和 C/P 之间存在很强的、统计显着的负线性关系（r = -0.855，p  < 0.001）。未受成岩作用改变的现代骨生物磷灰石样品具有低 IR-SF 和高 C/P 值。胶原蛋白产量或原子 C:N 比与 IR-SF 或 C/P 值之间没有显着相关性。有机产率在 0% 和 >20% 之间的样品的 IR-SF 和 C/P 值的变化范围涵盖了未受成岩作用改变的现代骨生物磷灰石以及受成岩作用显着影响的骨生物磷灰石的范围。骨无机和有机成岩作用之间缺乏预测模式表明沉积环境和地点形成历史在骨的有机和矿物部分中发挥着关键和独立的作用。因此，骨有机部分的保存并不能预示无机部分（例如生物磷灰石）的保存。