Preliminary Results of Petrographic and Electron-Spin-Resonance Studies of Organic Matter from Deep Sea Drilling Project Sites 370 and 416

Abstract

Petrographic observations confirm the continental origin of the organic matter and the presence of reworked, altered organic material in the sediments from DSDP Sites 370 and 416. The reflectance of the primary vitrinite-huminite population establishes that these samples are in the mature stage of evolution. The very low organic-carbon content of these samples makes ESR interpretation particularly difficult.

Generation and Migration of Low-Molecular-Weight Hydrocarbons in Sediments of Deep Sea Drilling Project Leg 79, Sites 544, 545, and 547, offshore Morocco

“…The claystones and calcareous mudstones of late Aptian age (Cores 545-55 and 545-56) contain 200 to 300 ng/g^These values are, despite a somewhat lower maturity (R o = 0.3% in the late Aptian according to Rullkötter et al, this volume), much higher than in calcareous mudstone/claystone samples of DSDP Hole 416A (deep Moroccan Basin). measured C 2 -C 7 hydrocarbon concentrations of 42.6 ng/g (6980 ng/g C org ) and 54.1 ng/g (12,300 ng/g C org ) in two Valanginian age samples of comparable kerogen type and organic carbon contents of 0.61 and 0.44%, respectively, at a maturity-level equivalent to a vitrinite reflectance of about 0.4% (Boutefeu et al, 1980). Their measurements were made, however, with a different analytical method comprising a slightly different molecular range.…”