Factors Affecting Bone and Tooth Preservation

By Brittany Mann, Session # 3, 2010

Modification by Physical AgentsChemistryFactors such as: soil acidity(pH) and

permeability, moisture, temperature, and microorganisms have dramatic affect on skeletal deterioration

Color and fossilization controlled by environment

best preservation occurs in: well drained areas with low water tables, in neutral or slightly alkaline pH soils in temperate areas

Modification by Physical Agents Cont’d

FireBones can be damaged by both natural

occurring fires as well as fires used for dietary and mortuary practices

Fire causes bones to change colour and crack

Burning can be confused with staining bones in some depositional contexts

Natural elements

Modification by Non-human Biological Agents

AnimalsCarnivores have a dramatic impact of

bone assemblagesCause damage by pitting, scoring, and

puncturing bone surfaceRodent gnawing is just as damagingBone can become polished and scratched

by being trampled by animals

PlantsRoots secrete acids which damages the

surface of buried bonesLeaves a network of shallow groovesGrooves are whiter in color than rest of

bone; this is caused by decalcification

Modifications by HumansHuman mortuary practices

causes profound effects of disposition of a skeleton such as: burning, cut/chop/scrape marks, fractures caused by hammering or pulverizing

Bone preparation and excavation can also cause damage; this can easily be diagnosed by colour

How do these factors impact materials found at Sanisera?

The End