Early and Middle Formative: San Lorenzo, Veracruz, México

Ceramic Analysis

The condition of the floodplain sherds ranges from almost pristine to extremely eroded. This difference in the state of preservation provides an opportunity to study the erosion with the idea of eventually classifying eroded sherds. Normally, eroded sherds are considered unclassifiable, however; eroded sherds themselves constitute a type based on their condition and color. Ann Cyphers (personal communication) also treats eroded sherds as a type. Eroded sherds with a gray paste would thus represent a type. Unfortunately, this can lead to all gray colored sherds with different temper size being lumped into one general category. Noting the differences and similarities in the characteristics of temper can help separate those sherds. Temper characteristics also allow for comparisons with established types or sherds in various states of condition. Thus, eroded sherds still have enough characteristics that can lead to their appropriate or established type assuming its type is represented in the ceramic assemblage. If the established type of an eroded sherd cannot be determined or defined as a new type, it would remain in the general type.

The majority of sherds occurred in the stratigraphic layers of the test units. I thus analyzed all sherds and not just those associated with features. The type of features discovered in the test units often had a low number of sherds. In some cases, no sherds were present (see Table 1, Table 6, and Table 14). In addition, some of the features were intrusive pits that date to later occupation levels. These intrusive pits could lead to problems in dating earlier features. Furthermore, analyzing all sherds helps track the movement of sherds for determining if the stratigraphic layers are disturbed. Thus, to ignore sherds from the stratigraphic layers would result in the loss of important data. This ceramic analysis therefore attempts to classify as many sherds as possible.

Ceramic analysis was carried out at the UNAM facility in Mapachapa, Veracruz, México with the permission of Dr. Ann Cyphers of the Instituto de Antropología (UNAM). I initially used both typologies as guidelines. I, however, quickly discovered that it is not that simple following established typologies because individual researchers may view a specific characteristic quite differently, especially, when dealing with color. Therefore, I returned to the basics. An assistant and I cleaned all sherds from every test unit before starting analysis. I used Ann Cyphers' cleaning method that incorporates a scalpel and a soft brush. Water tends to remove important surface treatments, such as slip. During the cleaning process, I noted the presence of diagnostic types as well as unique forms and surface decoration. This allowed me to verify observations made in the field.

All sherds from each test unit and their extensions were tended by metric level. Sherds related to features were placed between associated metric levels. The sherds of at least three test units were tended at one time. Those test units either were close to one another or shared the same area. This allowed for ceramic comparisons between test units or mounds. I lightly cleaned the sherds before separating them by surface color and paste. The additional cleaning resulted in finding surface treatments (e.g., red slip) not previously noted. Sherds were next grouped by appearance of temper. The sherds from each metric level and features were studied to identify diagnostic types and forms. The location of the diagnostic types as well as changes in phase was noted. This process allowed me to date specific features and stratigraphic layers as well as divide ceramic into established phases. It will also help me determine if sherds from different stratigraphic layers or occupation levels are mixed. I further noted increases and decreases in sherd frequencies. I compared this information to photographs and drawings of the stratigraphic profiles to determine if changes in sherd frequencies occurred in association with noted features as well as those not noticed during excavations but observable in the profiles. In some cases, I was able to associate the increase in ceramic frequencies to possible surfaces present in the profiles.

I analyzed rims first and then matched body sherds to rim. I used a flat platform with a vertical and horizontal scale to measure rim stance. These measurements were used to draw rim profiles. Modeling clay was used to make a mold of the interior and exterior of the sherd. I used a dissecting needle to trace the outline of the rim. I also used a digital caliper to make sure thickness was correct. This method reveals small changes in the lip of the rim that otherwise would be lost if only a pencil was used. The thickness of the lead tends to obscure small details. In addition to the profiles, the exterior of the all rim sherds, including those without decoration, was drawn. This allows for easy identification for future study. Partial reconstruction of rims was carried out to determine stance. In some cases, reconstruction resulted in complete profiles of vessels. I recorded rim and body sherd characteristics (e.g., color, paste, temper, diameter, form, and decoration). The temper was measured using two pen microscopes with 40x and 20x magnification. Both pen microscopes have internal mm scales. I noted particle size and shape. I used the Wentworth scale and U.S. Bureau of Standards Screen Scale (Wentworth 1922) for determining the particle size of temper; for example, very fine, fine, medium, and coarse. Separation of color was maintained to note variations within possible types. The Munsell Soil Color Chart (revised 2003 edition) was used to determine color. Body sherds with unique shape and decoration were also drawn. The form was noted with the appropriate number. I used Ann Cyphers' number system for form and decoration. I also noted all characteristics of individual body sherds to determine if they match analyzed rims and present typologies. This information will be used to correlate typologies. When no obvious match was found for rims or body sherds, they were treated as a possible new type. Possible new forms were also given a new number. Diagnostic sherds and unique forms will be photographed after analysis is completed. I will also photograph partial and complete vessels.

The described methodology is somewhat redundant and time consuming. However, the redundancy allows for verification of observation made at various points during analysis as well as expands on those observations. Therefore, the system of redundancy allows for a thorough analysis. It also helped maximize my knowledge of floodplain ceramics. More importantly, the knowledge gained expands on previous studies of the San Lorenzo ceramics.

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