This page summarizes a frequency-seriation chronology for the Poplar Forest Quarter Site developed by DAACS (see Neiman, Galle, and Wheeler 2003 for technical details). DAACS seriated ceramic assemblages, with more than 5 sherds, from individual excavated contexts and from stratigraphic groups -- groups of contexts that field records indicate were part of a single stratigraphic layer or deposit. Stratigraphic groups have a SG-prefix, which precedes the group number SG-prefix, (e.g. SG01 equals Stratigraphic Group 1). Not all contexts have stratigraphic group assignments.

DAACS chose to base its seriation chronology for The Poplar Forest Quarter Site on ceramic assemblages aggregated at the level of stratigraphic groups and unassigned contexts, and not at the level of features. Only eight features (F55, F65, F97, F75, F27, F96, F12, F87) contained more than five ceramic shreds. Frequencies of MCD types in these eight assemblages betrayed no convincing temporal structure.

DAACS computed the frequency of mean-ceramic-date (MCD) types in each stratigraphic group and each individual context that had no stratigraphic group assignment. The seriation chronology is derived from a correspondence analysis of these MCD-type frequencies. Seriated stratigraphic groups and contexts were assigned to phases. Phases are groups of assemblages that have similar correspondence-analysis scores and are therefore inferred to be broadly contemporary. Phases assigned by DAACS have a P-prefix that precedes the phase number (e.g. P01 equals Phase 1).

DAACS computed the frequency of mean-ceramic-date (MCD) types in stratigraphic groups and unassigned contexts. The seriation chronology is derived from a correspondence analysis of these MCD-type frequencies. Seriated assemblages were assigned to phases. Phases are groups of assemblages that have similar correspondence-analysis scores and are therefore inferred to be broadly contemporary. Phases assigned by DAACS have a P-prefix that precedes the phase number (e.g. P01 equals Phase 1).

The stratigraphic relationships among stratigraphic groups and unassigned contexts are summarized in the Harris Matrix for the site.

Based on the correspondence analysis, DAACS assigned the ceramic assemblages to one of four phases. Mean ceramic dates for the phases are given in the table below. The table also includes two estimates of the TPQ for each phase. The first TPQ estimate is the usual one – the maximum beginning manufacturing date among all the MCD-types in the assemblage. The second estimate -- TPQp90 -- is the 90th percentile of the beginning manufacturing dates among all the shreds in the assemblage, based on their MCD-types. This TPQ estimate is more robust against excavation errors and taphonomic processes that might have introduces a few anomalously late sherds in an assemblage.

Temporal distinctions among the four phases are small and may not be substantively significant. The Harris matrix reveals that phase assignments for stratigraphic groups and contexts do not correlate with stratigraphic order. The result further supports the idea that there is little chronological significance in variation among assemblages from separate layers on the site.

Click on the following link to access a seriation chronology for the Quarter Site. We use the indefinite article to signify that it is not the only chronology possible, nor even the best one possible.