Diagram of paragenesis in the three studied sub-sites A1 (including the tube T, the nodule N and the basal carbonate lens A1), E1 and R. It shows very similar paragenis characterized by a dark-brown micritic matrix with well-preserved shells or shell fragments replaced by calcite C1 (or aragonite) and disseminated pyrite (or marcasite). The light-brown drusy calcite C2 developed in contact with the micritic matrix. The equant calcite C3 and the microsparitic to equant calcite C4 (locally dolomite or aragonite) are in contact with the calcite C2 and appear cleaner, suggesting that this is the same continuous process of mineralization. The white microsparitic to blocky calcite C5 was identified in all sampling sites except R. Hydrocarbons or bitumen were evidenced in veins between C5 crystals only and as inclusions within the crystals or in quartz present in nodules. They were not evidenced above sub-site E1.