The Ploutonion of the archaeological site of Hierapolis (Turkey): a gate for the underworld and the knowledge

The archaeological site of Hierapolis (Denizli, Turkey), one of the great Hellenistic, Roman and Byzantine cities of southwestern Turkey, protected by UNESCO since 1988, was built in the third century B.C. Even if damaged several times by earthquakes, it has survived for millennia. During antiquity, Hierapolis was a famous pilgrimage destination, the centre of a cult, because of the Ploutonion, the sanctuary dedicated to Hades- Pluto and his wife Kore-Persephone, visited also by Cicero and Strabo. In this paper the authors report the results obtained on some materials found in recent excavations carried out in the Ploutonion area. In particular, the investigated materials were a marble bust, a fragment of marble slab with painted scales and a piece of resin. Non-invasive (i.e. imaging techniques and portable X-Ray Fluorescence) and micro-destructive (i.e. X-Ray Diffraction, Fourier Transform Infrared spectroscopy, High-Performance Liquid Chromatography coupled to a Mass Spectrometry detector and Pyrolysis coupled with Gas Chromatography/Mass Spectrometry) have been employed to characterize the archaeological finds.