Integration of Laboratory and Field Measurements on Soil and Bronze Artifacts: Facilitating Conservation Treatment and Management of Archaeological Collections

• Published in: Journal of the American Institute for Conservation 2023-04, Vol.62 (2), p.81-100
• Main Authors: MacLeod, Ian Donald, Boccia Paterakis, Alice
• Format: Article
• Language: English
• Subjects: Chloride; copper alloy; corrosion; decision-making model; Pourbaix diagram; redox potential; voltage
• ISSN: 0197-1360; 1945-2330
• DOI: 10.1080/01971360.2022.2143165

Chloride ion, pH, and voltage (redox potential) measurements were conducted in the field and conservation laboratory on soil and copper alloy artifacts deriving from two archaeological sites of the Japanese Institute of Anatolian Archaeology, Kaman-Kalehöyük (Kırşehir) and Büklükale (Kirikkale), in Central Anatolia, Turkey. The project established the impact of the burial environmental conditions on the state of the recovered metal artifacts and applied this information to the subsequent conservation management of the metal artifacts in the collection. These measurements may be used to determine the degree of stability of the metal artifacts for their long-term preservation. Based on the test results a conservation plan may be drafted according to three options: (1) active conservation intervention (e.g., treating with a chemical corrosion inhibitor or desalination); (2) preventive conservation through control of the environment; and (3) no protective measures necessary. Recommendations for conservators include simple tests on soil and representative artifacts as a guide to predict decay behavior for post-excavation collection management. These test protocols may be applied to the interpretation of material degradation at all archaeological sites and may be adapted for other porous materials. A decision-making model is provided in a flow chart.