Conservation begins the moment when structures and objects are discovered in an excavation. When the objects are unearthed, the equilibrium that had been maintained with the surroundings is broken. The changes that take place with the excavation can be so drastic that these objects can be completely destroyed if preventative measures are not taken immediately. The method of unearthing materials should be assured so that they are recovered in exactly the same state of preservation in which they were discovered.
All buried materials suffer a definite degree of degradation as a reaction to the environment in which they are subject. They may be found in a fragile structural state from a mechanical, chemical or biological point of view. For this reason, their treatment in the laboratory should be carefully outlined.
The conservation intervention should establish the correct diagnostic of the situation, the aims of the treatment and the methodology to be used. The work methodology should be correctly outlined and appropriate for each material and each case. For this reason, a series of exams should be carried out before beginning the intervention in order to identify the products of alteration, discover hidden decorations, qualify and quantify the components that will be the basis and guide for the treatments to be carried out.
In practical terms, the intervention of conservation and restoring of archaeological materials consists of four phases: cleaning (mechanical or chemical), stabilisation, consolidation and restoration (always carried out in function of the criteria related with preservation, study and publicity).
Ever since its beginning, Mértola’s Archaeological Site has understood that conservation and restoration are an integral and essential part for the study and preservation of the cultural estate under its responsibility. Thus, this institution maintains departments with specialized technicians that are permanently carrying out interventions not only on the finds arising from the archaeological interventions but also on the maintenance of objects on exhibition in the museum nuclei of the Mértola Museum and within its store.