Identification of organic compounds extracted from black weathered surfaces of Saxonean sandstones, correlation with atmospheric input and rock inhabiting microflora

The participation of organic compounds in weathering of Saxonean sandstones has been investigated. The organic and elemental carbon content as well as a few microbiological data of black weathered surfaces on historic buildings in Dresden have been obtained during preliminary studies. Organic compounds in the samples were analysed, after extraction, by gas chromatography-mass spectrometry. More than 150 compounds belonging to different chemical classes were detected. Their origin is discussed and correlated with data from the literature about organics in the atmosphere and with the microbiological results. Certain compounds contribute to the weakening of the rock structure.