Figure 4. Rock-Eval Van Krevelen-type diagrams for organic matter in Pliocene-Pleistocene sediments from Site 974 in the Tyrrhenian Basin, Site 975 on the Menorca Ridge, and Sites 976, 977, 978, and 979 in the Alboran Basin. Units for hydrogen index are milligrams of hydrocarbons per gram TOC and for oxygen index are milligrams of CO2 per gram TOC. Thermal alteration pathways of organic matter Types I, II, and III from source material to graphite are indicated by dashed lines.

Figure 4. Rock-Eval Van Krevelen-type diagrams for organic matter in Pliocene-Pleistocene sediments from Site 974 in the Tyrrhenian Basin, Site 975 on the Menorca Ridge, and Sites 976, 977, 978, and 979 in the Alboran Basin. Units for hydrogen index are milligrams of hydrocarbons per gram TOC and for oxygen index are milligrams of CO₂ per gram TOC. Thermal alteration pathways of organic matter Types I, II, and III from source material to graphite are indicated by dashed lines.