Figure F36. Calcium carbonate and total organic carbon content, hydrogen index, total sulfur content, and C/N and C/S ratios at Site 1194. The dashed vertical lines at hydrogen index = 150, C/N = 25, and C/S = 2 mark the approximate boundary between terrigenous (<150) and marine organic matter, the terrigenous organic matter field (~25-35), and the transition between marine and brackish environments of formation, respectively.