Maceral distribution, stratigraphic position and vitrinite reflectance at DSDP Hole 81-555

Twenty-four sediment samples from late Paleocene to early Eocene were studied for maceral content, vitrinite reflectance, and spectral fluorescence in order to determine some parameters of the origin and diagenetic history of their organic fraction. The sediments had been obtained at Site 555 of DSDP Leg 81 in the northeastern North Atlantic. The bulk of the microscopically visible fraction is made up of humic materials; inertinites follow as a distant second; and liptinites are exceedingly rare. No unequivocal evidence of marine organic matter was found. Humic materials are highly decomposed, showing signs of aerobic (frequency of sclerotinites) as well as anaerobic (abundance of and intimate association with framboidal pyrite) microbial degradation. Vitrinite reflectance values vary between 0.26 and 0.35 Ro and show a slight increase with depth. These values, indicative of a low-rank lignite stage of coalification, contrast somewhat with the sporinite fluorescence spectra, which show the configuration typical for the peat stage. In either case, the evidence for such a low stage of coalification is surprising in view of the depth and age of the sediments.

Magnetic properties and incompatible element geochemistry of some igneous rocks at DSDP Leg 64 Holes

I received five unoriented samples of igneous rocks from four Sites of Leg 64 of the Deep Sea Drilling Project (DSDP). I have measured several magnetic properties, alkalis (K, Rb, and Cs), alkaline-earth (Ba and Sr) element concentrations, and 87Sr/86Sr ratios of these samples. This study reports the results.

Methanogenic activity in sediments from DSDP Leg 64 Holes

We detected methanogenic bacterial activity in 6 of 12 sediment samples from Deep Sea Drilling Project (DSDP) locations in the Gulf of California.When samples were incubated anaerobically for three weeks at temperatures of 10 or 22°C, we found activity to sediment depths of about 12 meters. The methanogenic bacteria were inhibited by CHCl3 or 2-bromoethanesulfonic acid and were generally stimulated by H2.