Rock-Eval pyrolysis was conducted on ground bulk sediment samples (100 mg/sample) to determine (1) the amount of hydrocarbons (HC) already present in the sample (S1 peak in mg hydrocarbons per gram sediment), (2) the amount of hydrocarbons generated by pyrolytic degradation of the kerogen during heating up to 550°C (S2 peak in mg hydrocarbon per gram sediment), (3) the amount of carbon dioxide generated during heating up to 390 °C (S3 peak in mg carbon dioxide per gram sediment), and (4) the temperature of maximum pyrolysis yield (Tmax value in °C). Total organic carbon (TOC) values of the analyzed sediments were known from shipboard measurements (Heuer et al., 2017). The hydrogen index (HI) corresponds to the quantity of pyrolyzable hydrocarbons per gram OC (mgHC/gTOC), the oxygen index (OI) corresponds to the quantity of carbon dioxide per gram OC (mgCO2/gTOC). Tmax values < 435 °C are indicative for immature organic matter. In combination with HI values, Tmax values may give further information about the composition of the organic matter.The Rock-Eaval data are discussed in Kars et al. (2021/in review).