The thermal analysis of lichens growing on limestone

Abstract

In an investigation of the pedogenic activities of lichens growing on limestones it was found that they varied greatly in their calcium oxalate content. As chemical methods of determining calcium oxalate in such material are somewhat tedious, detailed qualitative and quantitative studies of oxalate in specific lichen species were made by using differential thermal and thermogravimetric analysis. The results show that in a controlled atmosphere of oxygen-free nitrogen, thermal methods provide a rapid means of identifying and determining calcium oxalate in lichens, and also enable an assessment to be made of the non-oxalate derived carbonate in the sample.