BCal help system: The Tutorial

Step A7: Radiocarbon data elicitation I

BCal now requires information about the radiocarbon data. For each group defined, BCal will show a page allowing us to enter information about the radiocarbon data for the determinations within that group. Since Layer III has only one determination, one form is shown.

The first field required is a label for the determination parameter that corresponds to this determination. Recall that this represents the unknown calendar age of the sample. Adopting the convention used in the literature, we label each determination parameter as "theta" plus a number (or word). We then enter the laboratory code of the determination, followed by the determination's mean and associated error.

The "Outlier probability" field allows us to inform BCal of the prior probability that a sample is an outlier. A sample may be considered to be an outlier if, for example, it has been contaminated at some point or does not date certainly date the event that it is stratigraphically associated with. We have no reason to believe that this sample (or any of the samples we are calibrating) has been contaminated and so we can leave this field as 0.

The final two fields allow us to specify a reservoir correction to use. This sample metabolised in an atmospheric environment and so we should leave both of these values as 0.