Geo‐environmental evaluation for the preventive conservation of open‐air archaeological sites: the case of the Roman Necropolis of Carmona (Spain)

The Necropolis of Carmona, which has more than 600 tombs carved in calcarenites, is among the most important Roman burial sites preserved in southern Spain. The tombs in the Necropolis show severe alteration and multiple weathering processes after being excavated at the end of the nineteenth century without a preventive conservation plan. The archaeological site shows strong anthropic modifications related to different excavation stages and in relation to the construction of facilities for the visiting public. In particular, the exposure of the buried tombs to meteoric conditions and anthropic modification of natural drainage have led to an important acceleration of the deterioration of the tombs. The conservation status of the Necropolis was defined through a comprehensive geo‐environmental study that combined field observations and laboratory data, modelling and digital mapping and environmental monitoring. Results allow a methodology to be developed providing guidelines to minimize potential risks when excavating new tombs (now buried) in the future. Moreover, the most suitable prospective areas can be defined inside the Necropolis in terms of the environmental, geological and geomorphological conditions which will enhance the preservation of newly exhumed tombs. Geo‐environmental preventive conservation methods that we propose can be entirely applied to other large archaeological sites completely exposed to open‐air atmospheric conditions.