A fusion of archaeology and conservation: Painted clay-covered basketry

Nancy Odegaard


Incorporating the discipline of professional conservation into the process of archaeological fieldwork in the American Southwest is both unusual and relatively recent. Complex archaeological investigations often include multi-component sites and analysis representing a wide range of specialists. Typical areas for grouping the analytical results of specialist studies may include chronological analysis, environmental analysis, osteological analysis, and artifact analysis. Though sometimes critical to the excavation process, conservation research has generally been utilized as a separate activity that is exclusive to the traditional analytical studies required in professional archaeology. More often, the interpretive observations of conservators are only received during the processes of post-excavation care when the artifacts have been accessioned and cataloged into a museum collection. This is usually long after the archaeological investigation and written interpretation phases have been completed. Also, because only certain artifacts may be selected for individual museum accessioning and cataloging, the observations made about them by the conservator during examination, cleaning, stabilization, storage, and exhibition remain in conservation files and are never incorporated back into the academic body of knowledge regarding the archaeological investigation.

Three clay-covered basketry vessels with painted decorations recovered from a 1995 Data Recovery Project in the Tonto Basin, Arizona illustrate the benefits of conservation research in the interpretation phase of certain artifacts from an archaeological investigation. Archaeologists from The Center for Desert Archaeology, a contract archaeology firm in Tucson, Arizona, contacted the conservation laboratory of the Arizona State Museum (ASM) for assistance after unsuccessfully excavating a unique painted clay-covered basket. A second basket that was partially excavated and a third that was lifted in a block were brought to the ASM conservation lab for study.

The clay-covered basketry vessels with painted decorations represented an extremely rare find in the archaeological record of the southwest region. The conservation study of these examples included:

1. Removal from the block lift of baskets 2 and 3.
2. Recovery of additional artifacts with basket 2.
3. Technical examination of basketry technology from clay impressions for all baskets.
4. Chemical characterization tests for the presence of cellulose with basket
6. Chemical characterization tests for pigments on all baskets.
7. FTIR analysis for indication of organic binder on basket 3.
8. SEM:EDS analysis for additional clay/pigment information on basket 3.
9. Extensive micro-photographic documentation of technical details for all baskets
10.Botanical identification by comparative study.
11.Technical comparison with four unpublished museum specimens.
12.Review of the archaeological literature of the SW for references to comparable technology.

Initially, project archaeologists viewed these containers as exotic and without significant comparison in the archaeological record Due to their extremely fragile and fragmentary state of condition, the archaeologists expected little could be revealed through a technical analysis. However, the application of techniques and methodologies used in the discipline of conservation to recover, examine and analyze the painted clay-covered baskets did result in important technological information. Aspects of the interpretive findings in the multi-component site were comparable and consistent with those of other artifact analyses which included ground stone, flaked stone, ceramics, shell, bone tools and ornaments, wooden objects, and worked stone. Additionally, several links to observations identified in the chronological, osteological, and environmental analyses were also noted.

The study of the painted clay-covered baskets was well suited to the application of a conservation based study. It illustrates the use of the conservation discipline beyond the application of artifact treatment and clarifies its value in the written interpretation phase of an archaeological investigation. The study also alerted archaeologists to several previously unknown aspects of the conservation discipline that were important for interpretation. As a result, the role of the conservator was better understood and utilized.

1999 | St. Louis | Volume 6