A small fluctuation in pH reading can make a big difference in the preservation potential, but it is not a direct relationship. There was no discernable difference in the state of preservation of bone from the two above-mentioned contexts. In both cases, the bone was in the same poor condition we have come to expect in the East Fork study area. It is apparent that pH alone is not the sole determining factor in bone preservation. In fact, it seems likely that as soil pH increases the potential for leeching also would increase, leading to a more rapid deterioration.
Bone is made up primarily of potassium and calcium.
If the surrounding soil is lacking in these minerals, they will be quickly removed from the bone when H2O is available in sufficient quantities to act as the catalyst. The water retention properties of southern Indiana soils are well known. Return to Top of Page Conclusion Based on pH readings, the soils at the Cox's Woods site cannot be characterized as acidic. Therefore, soil acidity as measured on a pH scale does not directly determine quality of bone preservation in archaeological contexts. In addition pH is a very localized and fickle property of the soil and can be effected by numerous agents other than subsurface archaeological deposits.