Organic geochemistry of Deep Sea Drilling Project sediments from the Gulf of Calofornia—hydrothermal effects on unconsolidated diatom ooze

摘要: Abstract The effects of intrusive thermal stress have been studied on a number Pleistocene sediment samples obtained from Leg 64 the DSDP-IPOD program in Gulf California. Samples were selected Sites 477, 478 and 481 where organic matter was subjected to sill intrusions. For comparison purposes, 474 479 as representative unaltered material. GC GC-MS data show that lipids thermally derived microbial terrestrial higher-plant detritus. proximities found contain thermally-derived distillates those adjacent sills contained essentially no lipids. Curie point pyrolysis combined with used kerogens reflected their predominantly autochthonous origin. Pyrograms altered much less complex than samples, reflecting effects. produce little or products since these intrusions into unconsolidated, wet sediments resulted situ matter. Examination by ESR showed spin density line width pass through maximum during course alteration but g -values correlation maturity. Stable carbon isotope (δ 13 C) values decrease 1–1.5‰ near at 477 atomic N/C decreases slightly proximity smaller Site 478. Differences maturation behavior between are attributed dissimilarities chemical isotopic heterogeneity Guaymas Basin protokerogen.