Figure F7. Close-up photographs of representative lithologies from the black shale of Unit IV. A. Transition between the two cyclic lithologies of laminated claystone with organic matter and laminated nannofossil chalk in the black shale of Unit IV (interval 207-1261A-47R-1, 84–100 cm). These two lithologies are separated by a bluish layer of coarse-grained diagenetic calcite. The nannofossil chalk is cut by a mineralized vein. B. Another bluish layer of coarse-grained diagenetic botryoidal calcite fan precipitated in a black claystone matrix (interval 207-1261B-48R-4, 67

Figure F7. Close-up photographs of representative lithologies from the black shale of Unit IV. A. Transition between the two cyclic lithologies of laminated claystone with organic matter and laminated nannofossil chalk in the black shale of Unit IV (interval 207-1261A-47R-1, 84–100 cm). These two lithologies are separated by a bluish layer of coarse-grained diagenetic calcite. The nannofossil chalk is cut by a mineralized vein. B. Another bluish layer of coarse-grained diagenetic botryoidal calcite fan precipitated in a black claystone matrix (interval 207-1261B-48R-4, 67–87 cm). C. Sharp transition between the laminated black shales of Unit IV and the quartz sandstone of Unit V (interval 207-1261A-50R-3, 13–35 cm).