X-ray diffractometry - For information about the mineral contents, the samples were ground and analysed by X-ray diffractometry (XRD) using a Panalytic Empyrean X-ray diffractometer. The mineral peak area intensities were determined graphically and calculated using Macdiff (Petschick 2012). Following Vogt (2009), the semi-quantitative mineral contents were determined by the ratio of the individual peak intensities against each other. Here we used the ratio of the quartz- and feldspar peaks, and the ratio of the illite peak against the total peak area intensities of all minerals (TI).Grain-size distribution - The samples were pretreated with acetic acid to remove the inorganic carbon. In order to destroy the organic compounds, a hydrogen peroxide treatment was conducted on a platform shaker, where ammonia was used for neutralization of the pH. The sample material was dispersed and homogenized on an overhead shaker using tetrasodium pyrophosphate. The grain-size distribution was measured using a Beckmann Coulter LS 200 laser particle analyser.Biogeochemistry - Total carbon (TC) and nitrogen contents were measured simultaneously using an elemental analyser (Elementar Vario EL III). The ground and freeze-dried samples were combusted in zinc capsules together with a spatula tip of tungsten oxide as a catalyst. The total organic carbon (TOC) contents were measured thereafter using an Elementar Vario MAX C analyser. Following Meyers & Teranes (2001), the TOC/N ratios (given in weight-%) were multiplied by the ratio of the atomic weights of carbon and nitrogen in order to obtain the atomic mass ratios (TOC/N atomic). For analysis of stable carbon isotopes of TOC, the samples were freed of inorganic carbon by hydrochloric acid, and measured using a Finnigan Delta-S mass spectrometer. The results are expressed as d13C values relative to the PDB standard in parts per mil notation (per mil).