Building i (Carpenter's Shop)
Building i Chronology
DAACS has developed a uniform set of methods 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 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.
DAACS Seriation Method
This page summarizes a frequency-seriation based chronology for the Building i site that was developed by DAACS (see Neiman, Galle, and Wheeler 2003 for technical details). DAACS seriated ceramic assemblages, with more than five 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 (e.g. SG01 equals Stratigraphic Group 1). For example, at the Building i site, two portions of a single layer, described by the excavators as ‘brown-red loamy clay', spanned two adjacent quadrats (1141 and 1144). The layer segments were excavated as 1141B and 1144B. DAACS assigned these contexts to a single stratigraphic group (SG01). Not all contexts have stratigraphic group assignments.
DAACS chose to base the seriation chronology for the Building i site on 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. In the few cases where stratigraphic groups and contexts were parts of features, the relevant feature numbers and descriptions are included in the seriation chronology table below.
DAACS computed the frequency of mean-ceramic-date (MCD) types in stratigraphic groups and in individual contexts when those contexts had no stratigraphic group assignment. 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. 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.
Building i Phases
Based on the correspondence analysis, DAACS divided the Building i site into two phases. Mean ceramic dates for these 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 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 a small assemblage derived from excavation of a deposit south of the south wall of the Carpenter's Shop, assigned by DAACS staff to SG02 and interpreted by the original excavators as a 'terracing fill layer'. These assemblages attest to the presence of a limited Jefferson-period occupation at the site. Phase two (assigned to SG03 and SG04) contains a signficant amount of post-Jefferson ceramics and may mark a post-Jefferson occupation, even though SG03 was originally described as a 'Jefferson Pd. Occupation Zone'.
A Seriation Chronology for the Building i Site
The following table presents a seriation chronology for the Building i site. We use the indefinite article to signify that it is not the only chronology possible, nor the best. DAACS encourages users of Archive data to help explore improvements.