Preliminary report on radiocarbon dates for ek xux and muklebal tzul

Preliminary Report on Radiocarbon Dates
for Ek Xux and Muklebal Tzul

By Marc A. Abramiuk

12 February, 2005

This report discusses the results and implications of calibrating eight carbonsamples that were collected from settlement at Ek Xux and Muklebal Tzul. Four carbon samples were collected from residential platforms at Ek Xux and four samples were collected from residentialplatforms at Muklebal Tzul; furthermore, the radiocarbon dates for these samples have been determined (see Kindon 2002 and Prufer 2002 for a more lengthy discussion on the collection and radiocarbon dating ofthe samples). Whereas eight carbon dates from the settlement of these sites are too few to make any detailed statements about the occupational history of these sites, it is worth analyzing what datawe have so that we have a solid basis for making any inferences regarding the nature of the relationship between Ek Xux and Muklebal Tzul. The radiocarbon dates of the samples received from thelaboratory were run through OxCal which is a software program that computes the associated calibrated dates of the radiocarbon dates.

Basic Theory behind the Calibration of Radiocarbon DatesConventionally, a radiocarbon date is conceptualized graphically as a bell-curve representing a normal distribution over a range of dates. What is not often realized however is that there is furtherprocessing that a radiocarbon date undergoes, and this processing facilitates in producing a more accurate representation of the radiocarbon date than a normal distribution. This post-laboratory processingis referred to as calibration, and radiocarbon dates must be calibrated if any chronological inferences (such as the identification of occupational sequences) are to be made (Aitken 1990).

Tocalibrate a radiocarbon date, a radiocarbon date is entered into OxCal as the mean of a normal distribution with an error quoted as one standard deviation. This is the form used by all radiocarbon...