Radiocarbon dating bp

If pretreatments were able to be uniformly implemented, there would have to be a uniform and predictable array of post-depositional characteristics between all samples. Each sample submitted for dating has its own specific depositional history.

The variety in environment and post-depositional features is reflected in the variety and complexity of pretreatment procedures and the variety of different types of dateable material (see above).

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Natural contamination occurs in the post-depositional environment.

Samples may be contaminated by material which make any radiocarbon result either too old or too young.

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.

A stratigraphical diagram should be drawn to enable the dater to understand completely the site and origin of the material, and to consider the ability of the lab to adequately date the sample in question.

The submitter should also indicate the degree of accuracy and precision required.

The following types of sample have been commonly radiocarbon dated: Since the 1950's, a number of researchers have concentrated on investigating and reducing the effects of this post-depositional contamination.

This field of inquiry is known as sample pretreatment and it is concerned with removing post-depositional contaminants by isolating sample fractions containing carbon which is autochthonous and therefore accurately dates the event in question.

This is particularly relevant for laboratories which use conventional methods of dating.

Bone dating, for example, requires large amounts of sample because the fractions which are usually extracted comprise a small percentage of the total material and the target fractions decompose rapidly.

This should be reported in the submission forms accompanying samples sent to the laboratory.

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