Soiling and blackening in archaeological sites and monuments of Iranian cultural heritage

The results of a study into the soiling on surfaces and reliefs at important Iranian archaeological sites are presented, paying particular attention to the carbon fractions not linked to the carbonate substrate, but originated by biological agents and anthropogenic activities. The authors illustrate and discuss the quantitative data for non-carbonate carbon, including elemental and organic fractions, obtained by applying the methodology developed during the CARAMEL EC Project, along with the organic composition of the soiling deposits (examined by thermally assisted hydrolysis and methylation, and gas chromatography-mass spectrometry)