Patterns of diagenesis in bone II: Effects of acetic acid treatment and the removal of diagenetic CO32

Archaeological bones of varying preservation have been treated with 0,1M ac etic acid in order to investigate the effect on structural and chemical alt erations caused by diagenesis. Acetic acid is commonly used as a "cleaning agent" for removing diagenetic carbonate from bone and enamel, in an attemp t to recover original, biogenic signals for use in dietary and C-14 dating studies. Diagenetic parameters were measured before and after treatment on a range o f archaeological bones with good and bad preservation. Histological preserv ation defined the behaviour of the correlating parameters, where correlatio n coefficients between carbonate content and crystallinity, microporosity a nd macroporosity increased significantly after treatment. For histologicall y well preserved material, acetic acid is effective at returning carbonate content to around that of modern bone. Where bone is extensively damaged by micro-organisms, "loose" diagenetic material can be removed, but a fractio n largely composed of hypermineralized bioapatite remains, which, we believ e, cannot be reliably used to obtain accurate biological signals. Copyright 2000 Academic Press