Abstract:
Archaeological heritage is social property which contributes to strengthening cultural identity; therefore, the objects, and the knowledge derived from them must be somehow returned to society. Preventive conservation must be applied in all stages the archaeological materials go through: excavation, moving or shipping, laboratory, storage and exhibition. On-site preventive conservation will help to ensure the long-term preservation of finds and information about their manufacture and use. The sudden change in the environment on excavation can cause rapid deterioration of an artefact if not stored in a suitable environment. The objective of a conservator is to minimize the post-excavation impact suffered by objects when they are removed from the ground and to take a series of preventive measures to delay the physical and environmental effects which lead to their deterioration, which are based on the control of the differences between outside and inside ground parameters. Before the excavation, the environment must be assessed, both above and below ground. The soil must be evaluated as to pH, salinity and physical structure. Working in wet contexts is different from working in dry, cold or warm ones. Organic materials are more vulnerable to deterioration factors. If wet organic materials are allowed to dry in an uncontrolled way, there will often be irreversible shrinking, distortion, cracking or collapse. Freshly excavated wet organic materials are vulnerable to biological attacks, particularly mould, due to increased temperatures, oxygen and light. Large or fragile objects will be vulnerable to breakage if they are excavated and handled without being supported. When objects are made up of more than one raw material, preventive measures must protect the material that is most sensitive to deterioration factors.
