Fig. 7.
(a) Glx vs Asx THAA d/l plot for Strombus samples investigated for the closed system test (white symbols) and for the archaeological applications on the Farasan island shell middens. Note that all samples fall on a coherent trajectory of protein degradation. Error bars represent one standard deviation around the mean. (b) “Spider diagram” for archaeological and “test” unheated Strombus shells from the Farasan Islands comparing the THAA d/l values for Asx, Glx, Ala and Val with the calibrated 14C ages of the archaeological layers.