Originally posted on Flinders Archaeology Blog:
Artefacts associated with submerged sites experience vastly different environmental and chemical effects than their terrestrial counterparts. Submerged sites often contain artefacts that terrestrial sites rarely exhibit, making the protection of these artefacts for future generations vital. Maritime archaeologists often have different approaches and methods of conserving previously submerged artefacts. For example, artefacts or materials that have been located in a sodium chloride solution (salt water) for extended periods are often well preserved but also friable in nature while artefacts recovered from anaerobic marine environments are also in better condition than those recovered from aerobic environments.
In the vast majority of cases, artefacts and materials that have survived have done so by reaching a chemical and physical equilibrium with their environment. If researchers do not conserve these artefacts properly and in a timely manner after their recovery, they are likely to deteriorate at an extremely rapid rate (Hamilton, 1997:4). Artefacts that are allowed to dry without conservation treatment produce sodium chloride crystals, which, in some cases, cause the artefacts to break and splinter, thereby destroying them. It is also important to note that organic and inorganic materials react differently to salt water (Hamilton, 1997:4). This blog will identify and outline some basic conservation techniques used to conserve both organic and inorganic artefacts, focusing primarily on chemical conservation.