Ken Caryl Brown Ware Project (KCBWPRJCT)
Archaeologists working in eastern Colorado occasionally encounter brown ware sherds with distinctive rippled exterior surfaces that result from using a cord wrapped paddle in the manufacturing process. Long recognized as a marker of the Plains Village Tradition, these cord marked ceramics are similar to ceramics found in an enormous area stretching from the Dakotas to Oklahoma and Texas to eastern Colorado. In 2002 the Institute was approached by the Denver Chapter of the Colorado Archaeological Society to verify that cord marked ceramics recovered at Swallow Shelter (5JF321) in the Ken Caryl Ranch area near Denver, Colorado were manufactured in the immediate vicinity. http://www.coloradoarchaeology.org/Denver/index.htm Their request was unusual because archaeologists traditionally use ceramics to date the occupation of associated sites. In order to determine their locale of manufacture we rely on the resource approach to ceramic analysis, which serves to document clay and temper type variability in the ceramic artifacts and comparison with the various clay and temper types available in the general site area. The resource approach relies on the resource proposition, which states that the combination of unique clay and temper types for ceramic production documents the physical association of potters with a geographic locale of resource availability. This assumption is based on the observation that potters in pedestrian societies situate themselves in proximity to their ceramic resource base rather than transport the bulky clay and temper materials. Simply stated, the location of clay and temper sources in the local landscape that match those observed in archaeological ceramics is a strong argument for local ceramic production. Similarly, the lack of congruence between the local ceramic resource landscape and the ceramic artifacts would suggest that the pottery was manufactured elsewhere.
The first step in the analysis is to subject a portion of each archaeological artifact to refiring analysis, which serves to bring all samples to a comparable state. Cord marked ceramics are usually sooted (from repeated use over a smoky campfire) and refiring removes the carbon and also allows for expression of the iron content of the clay, iron being the primary coloring agent in clay. Clay type variability is documented in terms of Munsell Soil Color notations and since the iron content of clays is variable, each refied clay color basically documents a unique clay source. Temper types are observed using a binocular microscope and characterized in terms of general categories such as coarse granite sand, which was the temper type observed in all ceramic artifacts from Swallow Shelter.
The complimentary second step of the analysis is to collect and process clay and temper voucher samples from the local ceramic resource landscape. Fred Rathbun, retired geologist and Denver Chapter member supervised the collection of temper and clay voucher samples from the various formations in the general catchment of the Swallow Shelter. Temper samples were directly compared to the temper in archaeological artifacts and clay samples were subjected to identical refiring analysis procedures and compared in terms of Munsell Color notations. Despite the ready availability of visually identical coarse granite sand (derived from the Fountain Formation) in the area, not one of the refired clay colors were replicated in the local resource base, strongly suggesting that none of the ceramics were manufactured locally.
The ensuing question of "Where were they made?" led us to predict that the pottery was manufactured somewhere along the Front Range Hogback, especially given that several vessels were made from a distinctive red clay from the Morrison Formation, which is widely available in hogback exposures. Cursory examination of various portions of the hogback points to a probable source in the Roxbourough State Park area. Reconstruction of the nature of ceramic production based on ceramic analysis data from a single site is patently impossible, and the geologic complexity of the hogback ceramic resource base precluded continuation of the project until additional ceramic analysis could be accomplished.
The Ken Caryl Brown Ware Project was revived in 2005 when Centennial Archaeology of Fort Collins contracted us to perform the same analysis on a selected sample of cord marked ceramics excavated from 5DA1957, located in Newlin Gulch near Parker, Colorado. Following the procedures outline above, the compositional variability of archaeological artifacts and the local ceramic resource base was documented. As with Swallow Shelter, coarse granite sand was observed in the ceramic artifacts and was locally available, but none of the local clay sources matched the clay types documented in the artifact analysis. It is therefore unlikely that the ceramics recovered from the excavation were manufactured in the immediate area.
So our current understanding is that cord marked pottery was probably being manufactured somewhere along the Front Range Hogback and accompanied Plains Village affiliated social groups in their economic activities. When site locations with cord marked pottery are plotted on the map of eastern Colorado, most are clustered along the hogback, with occasional sites extending out into the eastern Plains and into the valleys behind the Front Range mountains, suggesting a geographic association with the South Platte River. However, the occurrence of sites in the general area of the Platte River suggests that the prehistoric pottery using inhabitants may have been exploiting the entire length of the drainage basin. Future research has three complimentary goals. First, we need to expand our data base to ensure that we know the entire range of paste compositional variability in cord marked ceramics. Second, we need to locate geographic locales with ceramic resources that match those observed in the artifacts; the amount of paste variability suggests multiple locales of production. Third, we hope to expand the scope of our view in order to identify related (and possibly ancestral) ceramic traditions to the east.