(Appendix) Total organic carbon, pyrolysis characteristics, and organic matter types at DSDP Holes 77-535 and 77-540

• Main Authors: Summerhayes, Colin P, Masran, Theodora C
• Format: Dataset
• Language: English
• Published: PANGAEA 1984
• Subjects: 77-535; 77-540; Carbon; organic; total; Charcoal; Deep Sea Drilling Project; DEPTH; sediment/rock; DRILL; Drilling/drill rig; DSDP; DSDP/ODP/IODP sample designation; Element analyser CHN; LECO; Epoch; Event label; Glomar Challenger; Gulf of Mexico; Gulf of Mexico/BASIN; Hydrogen index; mass HC; per unit mass total organic carbon; Leg77; Light microscope; Lithologic unit/sequence; Lithology/composition/facies; Organic matter; amorphous; aquatic; terrigenous; Oxygen index; mass CO2; Pollen and spores; Rock eval pyrolysis (Espitalié et al. 1977); Sample code/label; North Atlantic
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.809302; https://doi.org/10.1594/PANGAEA.809302

Lower to middle Cretaceous sediments in the eastern Gulf of Mexico are richer in organic matter and have a more marine organic facies than their counterparts in the nearby western North Atlantic, suggesting that the Gulf was the more productive of the two areas. As in the western North Atlantic, the rate of supply of terrestrial organic matter was high when the rate of supply of noncarbonate clastic materials was high (at times of low sea level) and diminished as sea level rose. The rate of supply of marine organic matter was lower in the Early Cretaceous than in the Cenomanian, perhaps in response to the global rise in sea level over this period. Where they are thermally mature, the organic matterrich units drilled at Sites 535 and 540 should be excellent sources for liquid hydrocarbons. The Pleistocene sediments of the eastern Gulf are dominated by terrestrial organic matter representing Mississippi River effluent.