Sampling Cerros' Demise: A Radiometric Check on the Elusive Protoclassic

Analysis

Having compiled a total of twelve usable radiocarbon dates from Cerros, these were then arranged chronologically showing both y-intercept and intervals (Figure 8). It is immediately obvious that two distinct date ranges are indicated. The earlier component, consisting of the four SMU dates from village and canal domestic debris, is distinct. Cliff (1982), Scarborough (1991) and Freidel (pers. comm. 2004), have questioned the validity of the canal date (SMU-774). With a 2-Sigma span of roughly 800 years, its utility is minimized, and it can be eliminated from the analysis.

The remaining three dates on early domestic debris show a 2-Sigma cluster in the range of 400 - 50 BCE, with some emphasis on the earlier portion of that era. This range best defines Early Tulix as we currently understand it. One date with a large 1-Sigma range (SMU-881) extends later in time, but none extend much earlier than 400 BC. Significantly, there is little overlap between this cluster and the later one.

The later cluster is comprised of the two SMU dates from non-domestic contexts as well as the Beta dates, all drawn from monumental contexts (Figure 9). One date, from Str. 5E-Sub 1 (Beta-188413), has a y-intercept right at 50 BCE, and a larger 1-Sigma range overlapping with the earlier cluster. The 1-Sigma ranges for all other dates in this group are small and fall completely within Late Tulix (50 BCE - 150 CE), clearly defining the later facet.

Of this group, SMU-776 is drawn from Str. 2A-Sub 4-1st, a two-tier stone pyramid situated at village level just east of the site core (Figure 10). The others are from monumental construction episodes, use, or building termination (Garber 1983). Four of the five latest dates within the cluster stem from late use or site abandonment contexts (SMU-906, Str. 29C-E termination; Beta-188412, Str. 5E late use; Beta-188418 Str. 4AB termination; Beta-188406, Str. 4AB termination). Both samples from Str. 4AB termination debris have late y-intercepts (80 CE, 115 CE) and 2-Sigma ranges that extend beyond 150 CE, into Early Classic Hubul Phase.

The suite of dates now available for Cerros shows a coherent range, conforms to expectations, and mirrors stratigraphic relationships well. It is also clear that both SMU and Beta dates overlap in expected ways, indicative of their validity. Two relevant points should be recognized. (1) The short 1-Sigma ranges on most Beta dates may be attributed to their small sample size; they are AMS (Accelerator Mass Spectrometry) dates, which can provide a more accurate result. The only standard Beta date (Beta-188413) has a wider 1-Sigma range. (2) Early Tulix is dated only by domestic debris and Late Tulix is dated only by non-domestic debris. Robertson-Freidel (1980) defined these contexts. While Late Tulix households were excavated (Scarborough 1991; Walker et al. 1997), no datable samples were obtained by either project. This may be due to a settlement shift in Hubul Phase, leaving ruined Late Tulix house mounds exposed to the elements for nearly 2000 years. Even in view of these shortcomings, however, the overall suite of dates is internally consistent and suitable for interpretation.

Previous Page  |  Table of Contents  |  Next Page