Environmental impact assessment on the stone decay in the archaeological site of Hierapolis (Denizli, Turkey).

The archaeological site of Hierapolis (Denizli province, Turkey) is unique in terms of the conservation of marbles and travertines. Environmental factors (i.e. interaction with thermal waters, high thermal stress, CO degassing) and geological aspects (presence of seismic faults, frequent earthquakes, formation of travertine) play a fundamental role in the durability and conservation state of the stone materials. This paper presents a multi-analytical approach aimed to identify the phenomena and causes of stone decay related to environmental conditions. The analyses of alteration and decay phenomena are discussed together with the monitoring of the main environmental parameters and with analyses of waters and gases present in the archaeological site. Finally, the need of a continuous monitoring of the environmental parameters affecting the archaeological site is stressed.