Microscopy images of the sampled areas in MC1–MC4, given in panels (A)–(D), respectively. The corresponding intensity maps of ¹²C are given in panels (a)–(d) (pixel size of 10 μm). For the location of the investigated areas on the sample, see Figure 3, panel (A). A correlation with the darker areas on the microscopy image with enhanced carbon abundance is clearly visible. For campaign parameters, see Table 1. Panel (A) shows the distribution of CM around a pseudomorphed volcanic particle with the CM extending outwards into the surrounding, fine-grained sedimentary matrix. This textural relationship suggests the CM is indigenous to and syngenetic with the sediment deposition.