A Comparative Archaeological Study of Colonial Chesapeake Culture (www.chesapeakearchaeology.org)

• About the Project
• Site Summaries
  • Sandys
  • Carter’s Grove CG8
  • Reverend Buck
  • Rich Neck Plantation
  • Jordan’s Journey
  • Old Chapel Field
  • Clifts Plantation
  • Camden
  • Posey
  • Mattapany
  • Compton
  • Patuxent Point
  • King’s Reach
  • Chaney’s Hills
  • Chalkley
  • Burle's Town Land
  • Homewood's Lot
  • Bennett’s Point
• Map
• Interpretations and Papers
• Database
• Downloads
• Technical Data

Analysis Procedures

"Analysis" in this project means the quantitative evaluation of spatial artifact distributions and the organization of material by function or form from the various middens. This analysis was undertaken by the project staff, under the direction of lead project archaeologist Catherine Alston, and is provided on linked pages on the various site summaries. Interpretations of the distribution maps and midden charts are given in the various interpretive papers.

This section describes the procedures used in this analysis.

Artifact Distribution Analysis

Artifact distribution maps are useful for presenting visual representations of selected types of materials recovered from an archaeological site, including their quantities and spatial locations. For this project, most of the distribution maps we produced represent materials recovered from plow zone contexts. In a few cases, spatial distributions of materials recovered from feature contexts were also generated to augment the plow zone evidence. The maps we produced are available as downloadable PDF documents. These maps were generated using the SURFER mapping program available from Golden Software, Inc.

Although we elected to use the SURFER mapping program, the methods we used to construct each map are not unique to SURFER. First, it is important to remember that these distribution maps represent projections based on a set of sampled evidence. The reliability of each map is only as good as the underlying data on which it is based. The SURFER distribution maps generated here are from information contained in specific data points (or excavation units, see below)—the greater the spacing between data points (or excavation units), the less reliable the projected representation. In addition, studies have shown that systematically-collected data rather than data collected from ‘critical points’ (i.e., areas of high or low concentration) yield more reliable results.

In our maps, data points represent the center point of excavation units. For example, a five-by-five-foot excavation unit with grid coordinates of N100-N105/E200-205 would have its data point represented as N102.5/E202.5 (center point of the unit). All materials recovered from that particular five-by-five-foot unit would be assigned to that data point. Not all projects used five-by-five-foot units, however; some projects used 2.5-by-2.5-foot or 1-by-1-meter units. In a very few cases, excavation units used at the same site varied in size. We standardized units by using multipliers. For example, at the Sandys site (44JC802), excavators used both 2.5-by-2.5-foot and 5-by-5-foot units. To standardize counts, then, we multiplied quantities of material recovered from 2.5-by-2.5-foot units by 4 (alternatively, we could have divided materials from 5-by-5-foot units by 4). While not a perfect measure, this method allows data point values to be standardized and therefore more reliably comparable.

Next, interval levels were calculated for each map. In other words, what levels of artifact concentration should our maps show? First, the total number of a particular artifact type was calculated. For example, for a map of the distribution of tin-glazed earthenware, we calculated the total number of fragments in the map’s database, along with the mean and standard deviation. These are common statistics and can be easily reproduced by researchers evaluating our data or generating new maps. We believe that these statistics are better than simply “eyeballing” interval levels. Indeed, we have found that using an eyeball method can be difficult to reproduce for the same researcher, let alone others. Interval levels were then calculated by distance from the mean using ½ standard deviation.

Midden Analysis

At most domestic sites in the colonial Chesapeake, refuse was often deposited in yard areas adjacent to doors and windows, and activities conducted in the nearby spaces can often be inferred from materials recovered from the associated middens. This pattern of refuse disposal is clearly evident at the 18 sites used in this study, and project participants developed a standard method for identifying and then analyzing middens at these sites. This analysis took into account that most sites in the Chesapeake have been subjected to post-occupational agricultural plowing at one time or another, undeniably damaging the archaeological integrity of midden deposits. Nonetheless, the horizontal relationships of materials found in midden deposits are only minimally disturbed (click here for more on the importance of plow zone archaeology), suggesting that information on the use of space within these domestic or household sites is recoverable from plow-disturbed midden deposits.

Initially, artifact distribution maps were prepared for each site. Then, project participants visually compared maps from the same site to identify midden areas. Overlapping concentrations of ceramics, tobacco pipes, glass, and animal bone indicated a potential refuse midden or area where refuse was consistently deposited.

Once midden areas were visually identified, plow zone excavation units from within those areas were pulled and aggregated. In some cases, especially at sites occupied for long periods of time, midden areas were difficult to identify. In those cases, sections of yards (i.e., north yard, south yard) have been analyzed. Although the types and groups of artifacts selected for further comparison may vary from site to site, in general, the following categories of artifacts were compared:

Stem bore diameters of white clay tobacco pipes

Stem bore diameters provide useful chronological information, especially with regard to changing patterns of refuse disposal at a site.

Total Artifacts

This category generally includes white clay tobacco pipes, red clay tobacco pipes, ceramics, bottle glass, and animal bone, and can provide evidence about activity areas within a site.

Ceramics

Ceramics have been broken out by type and, when available, by vessel form. Both temporal and functional information are available here.

For comparative purposes, raw counts of various material types were converted to percentages; a chi-square test was used to measure strengths of association.

In some cases, such as at Jordan’s Journey, the analysis of plowed midden deposits was not attempted because the available data are not sufficiently robust to produce reliable interpretations. In that case, and in a few other instances, materials recovered from spatially distinct feature contexts were compared in an effort to explore intrasite spatial structure.