FRESENIUS ENVIRONMENTAL BULLETIN, vol.18, no.4, pp.499-504, 2009 (SCI-Expanded)
This paper discusses micro-morphological changes induced by lichen weathering at the interfaces between different types of lichen and their substrates composed of Miocene andesite, observed 10 km east of the city of Çanakkale, NW Turkey. The evidences of physical and chemical weathering that occur at SW facing surfaces of lichenencrusted andesite were studied based on energy dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM), as well as inductively coupled plasma atomic emission spectrometry (ICP-AES) analyses. Our results showed that both lichens contribute to the weathering of andesite, but with different rates. The weathered substrates under the lichens involved were determined to have increased amounts of Al, K, Ca, and Fe, but a decreased content of Si, suggesting either protective role of lichens against chemical weathering or precipitation of organic salts and iron oxides during lichen growth.