Diagnostics and monitoring in the Mithraeum of Marino Laziale (Rome)

The diagnostic campaign and the microclimatic monitoring in the hypogeum environment of the Mithraeum of Marino Laziale started in 2018. This suggestive and mysterious archaeological site, situated a few kilometres away from Rome, is not accessible to visitors yet [1]. The aim of the research is the definition of strategies for its fruition in compatibility with a conservation protocol planned according to the Municipality of Marino to finally support the opening of the Mithraeum. Because the site conditions are still compromised after 10 years from a preliminary diagnostic campaign and a previous restoration work, on the three paintings of this hypogeal environment a new diagnostic campaign was planned. The main risk of decay for the wall paintings was identified in the potential changing of the hypogeum environment equilibrium that could induce salts crystallisation on the painted surfaces and biological growth [2, 3]. In this paper the main results of the diagnostic campaign (optical microscopy, imaging techniques, portable FT-IR spectroscopy and XRD and bioluminometer (ATP), compared with previous diagnostic results (2008 campaign on the wall painting of Mithras and the Bull), and both correlated with microclimatic parameters are discussed.