Elemental analysis of the total carbon (C), total nitrogen (N) and total sulphur (S) content was measured with a vario microcube (Elementar, Germany) on 2 mm thick sub-samples of the profile PRM8-A. Due to the sticky consistence of the material the samples could not be homogenized prior to analysis and each sample was measured in four replicates of c. 2.5 mg (± standard deviation of the mean).Contents of total carbon, total nitrogen and total sulphur %, reported values are mean values of 4 replicates and standard deviation of the mean.