Bone fish dating
Artificial contamination may be blamed on human negligence during the collection and processing of samples.
Contaminants often include ash from tobacco, hair and fibres, paper from packing material and oil or grease (Hogg, 19).
Nevertheless, there are certain laboratory procedures which are associated with specific sample types and environments, and a number of accepted and often repeated pretreatment methods. The laboratory decides on the most effective pretreatment procedure through a careful examination of each submitted sample.
A number of variables feature in this consideration, one of the most important concerns the environment within which the sample was deposited.
The most common source of contamination by modern carbon is caused by rootlet intrusion.
Organic samples such as wood, charcoal, soil and bone are especially prone to this and should be examined closely before, and after collection, for evidence of root penetration (Hogg, 19).
Natural contamination occurs in the post-depositional environment.
Contamination may be artificially or naturally caused.
Often, submitted samples are divided and one portion retained as a reference in case the original sample is lost, or a further date required.