Figure 1. Plot of contexts along CA Dimensions 1 and 2. Time runs from right to left.

We perform a standard set of analyses to infer intra-site chronologies for the sites included in the Archive. Using them, we have assigned most excavated contexts at each site to a set of site-specific phases. The use of common analytical methods is designed to increase comparability among phases at different sites. The methods and the phase assignments they produced are summarized below. For some sites, the original excavators developed intra-site chronologies and, where these exist, they are included on the Background page for the site. DAACS encourages users of Archive data to help explore improvements.

Figure 2. Plot of MCD Types along CA Dimensions 1 and 2. Note that later types are on the left.

Figure 3. CA Dimension 1 scores plotted against Mean Ceramic Dates.

Figure 4. Histogram of ceramics from the Project plotted along CA Dimension 1. The lines indicate DAACS phase divisions.

This page summarizes the frequency-seriation-based chronology we developed for the Building m site (see Neiman, Galle, and Wheeler 2003 for technical details). 

As with other sites in the Archive, the seriation chronology for the Building m site was derived from ceramic assemblages aggregated at the level of contexts and stratigraphic groups, and not at the level of features. This is because most contexts and stratigraphic groups on the site were not parts of features. For the relatively few cases where seriated contexts and stratigraphic groups were parts of features, the relevant feature numbers and descriptions are included in the seriation chronology table below. The seriation chronology is the result of a correspondence analysis of MCD-type frequencies in each stratigraphic group and each individual context that had no stratigraphic group assignment (Figures 1 and 2). Not all contexts have stratigraphic group assignments. 

To reduce the noise introduced by sampling error, only ceramic assemblages with more than 5 sherds and more than one ceramic type from individual excavated contexts and from stratigraphic groups were included. F01 (Fenceline Posthole), SG02 (Modern Mulberry Row Road), SG09 (Lower Fill East of Foundation), and SG10 (Smokehouse/Dairy Occupation Layer) were removed from the seriation of Building m in an iterative process due to unusually high contributions of these SGs to inertia. The subsequent results produced a strong correlation between Dimension 1 scores and MCDs (Figure 3). Based on the dips in ceramic counts observed in a histogram of Dimension 1, we divided the Building m site into four phases (Figure 4).

Phases are groups of assemblages that have similar correspondence-analysis scores, similar MCDs, or both, and are therefore inferred to be broadly contemporary. Phases have a P-prefix that precedes the phase number (e.g. P01 equals Phase 1).

Mean ceramic dates for the site-specific phases are given in the table below. The table also includes two estimates of the ceramic 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 sherds 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.

Phase one is comprised primarily of assemblages from excavation of the original Jefferson-period ground surface that we assigned to SG13. Phase two assemblages form the main Smokehouse-Dairy floor layer (SG12) and two contemporary deposits exterior to the foundation (SG08 and SG11). Phase three primarily dates the MRS 4 occupation (SG05) and a trench along a fenceline north of the structure (SG04), both of which post date the Smokehouse-Dairy proper. Phase four is the latest phase and contains a substantial amount of post-Jefferson ceramics. SGs assigned to P04 include excavation backfill (SG03b) and a late fill layer (SG06).

The following table presents a seriation chronology for the Building m site. We use the indefinite article to signify that it is not the only chronology possible, nor the best. We encourage users of Archive data to help explore improvements.

The stratigraphic relationships among stratigraphic groups and unassigned contexts are summarized in the Harris Matrix for the site. Phase assignments from the seriation are shown on the Harris Matrix in color, facilitating comparison of the seriation chronology and the stratigraphic chronology of the site.