Sedimentary organic matter preservation: an assessment and speculative synthesis

The second edition of The Biomarker Guide is a fully updated and expanded version of this essential reference. Now in two volumes, it provides a comprehensive account of the role that biomarker technology plays both in petroleum exploration and in understanding Earth history and processes. Biomarkers and Isotopes in the Environment and Human History details the origins of biomarkers and introduces basic chemical principles relevant to their study. It discusses analytical techniques, and applications of biomarkers to environmental and archaeological problems. The Biomarker Guide is an invaluable resource for geologists, petroleum geochemists, biogeochemists, environmental scientists and archaeologists.

The Biomarker Guide

Biogenic methane formation in marine and freshwater environments: CO2 reduction vs. acetate fermentation—Isotope evidence

Organic detritus passing from the sea surface through the water column to the sea floor controls nutrient regeneration, fuels benthic life and affects burial of organic carbon in the sediment record1–3. Particle trap systems have enabled the first quantification of this important process. The results suggest that the dominant mechanism of vertical transport is by rapid settling of rare large particles, most likely of faecal pellets or marine snow of the order of >200 μm in diameter, whereas the more frequent small particles have an insignificant role in vertical mass flux4–6. The ultimate source of organic detritus is biological production in surface waters of the oceans. I determine here an empirical relationship that predicts organic carbon flux at any depth in the oceans below the base of the euphotic zone as a function of the mean net primary production rate at the surface and depth-dependent consumption. Such a relationship aids in estimating rates of decay of organic matter in the water column, benthic and water column respiration of oxygen in the deep sea and burial of organic carbon in the sediment record.

Particulate organic carbon flux in the oceans—surface productivity and oxygen utilization

http://www.ldeo.columbia.edu/~peter/site/Papers_files/deMenocal.2004.pdf

African climate change and faunal evolution during the Pliocene-Pleistocene

Comparison of rates of accumulation of organic carbon in surface marine sediments from the central North Pacific, the continental margins off northwest Africa, northwest and southwest America, the Argentine Basin, and the western Baltic Sea with primary production rates suggests that the fraction of primary produced organic carbon preserved in the sediments is universally related to the bulk sedimentation rate. Accordingly, less than 0.01% of the primary production becomes fossilized in slowly accumulating pelagic sediments [(2 to 6 mm (1000 y)−1] of the Central Pacific, 0.1 to 2% in moderately rapidly accumulating [2 to 13 cm (1000 y)−1] hemipelagic sediments off northwest Africa, northwest America (Oregon) and southeast America (Argentina), and 11 to 18% in rapidly accumulating [66 to 140 cm (1000 y)−1] hemipelagic sediments off southwest America (Peru) and in the Baltic Sea. The emiprical expression: % Org-C = 0.0030· R · S 0.30 p s (1−θ) implies that the sedimentary organic carbon content (% Org-C) doubles with each 10-fold increase in sedimentation rate (S), assuming that other factors remain constant; i.e., primary production (R), porosity (φ) and sediment density (ps). This expression also predicts the sedimentary organic carbon content from the primary production rate, sedimentation rate, dry density of solids, and their porosity; it may be used to estimate paleoproductivity as well. Applying this relationship to a sediment core from the continental rise off northwest Africa (Spanish Sahara) suggests that productivity there during interglacial oxygen isotope stages 1 and 5 was about the same as today but was higher by a factor of 2 to 3 during glacial stages 2, 3, and 6.

E. Suess

Papers

Productivity, sedimentation rate, and sedimentary organic matter in the oceans—I. Organic carbon preservation