Figure 5
From: Early Evidence for Northern Salmonid Fisheries Discovered using Novel Mineral Proxies
Infrared spectra showing alterations of the phosphate component in burned and hydrated fish bone. v3 and v4 phosphate absorbance bands for modern Atlantic salmonid vertebrae (A), brown trout (B), Arctic char (C), whitefish (D), northern pike (E), and bream (F) burned at 800 °C. The uppermost spectra in each panel are the experiment starting points of burned but not hydrated bone, while the lower spectra are the results of 50 µl treatments with the designated solution. Wavenumbers (cm−1) for each absorbance band are specified, and bands for whitlockite and beta magnesium tricalcium phosphate are labelled in red. Note that beta magnesium tricalcium phosphate bands decrease and hydroxylapatite bands increase upon hydration, and that WH reformed in Atlantic salmonid and brown trout following hydration with acidic solution. Additional details are presented in Supplementary Information B. Abbreviations: PO4 = phosphate; HAp = hydroxylapatite; OH = hydroxyl; WH = whitlockite; TCP = beta magnesium tricalcium phosphate; H2O = water; HCl = hydrochloric acid.
