Marine sedimentary organic matter : delineation of marine and terrestrial sources through radiocarbon dating; and the role of organic sulfur in early petroleum generation
Benitez-Nelson, Bryan C.
MetadataShow full item record
This thesis details two years of research conducted with the guidance and support of three advisors: Dr. J. K. Whelan, Dr. J. S. Seewald and Dr. T. I. Eglinton. Each of the three chapters represents a different, self-contained research project. All of the projects are related to the organic geochemistry of marine sediments, however, this is a fairly encompassing area of study. Chapters 1 and 2 stem from the same experimental study -the use of hydrous-pyrolysis to investigate mechanisms leading to the production of petroleum-related products during kerogen maturation. Chapter 3, on the other hand, utilizes a recently developed technique of isolating and AMS-14C dating individual compounds from complex sedimentary organic mixtures. The samples used in each investigation came from all over the world. The first two chapters utilize ancient marine sediment samples obtained from an outcrop in California (Chpts. 1 and 2) and from a well in Alabama (Chpt. 2). In contrast, recent marine sediment samples were obtained from the Arabian and Black Seas for the third chapter. Several preparative and analytical methods are common to all three studies. Nevertheless, each employ techniques totally unique from one another and from previous investigations. In Chapter 1, for example, X-ray absorption spectroscopy (XANES) is used to determine the speciation of organic sulfur present in kerogen, bitumen, and bulk sediment samples. While Chapter 3 represents the first study in which the 14C ages of individual, known hydrocarbon biomarkers are determined after isolation by Preparative Capillary Gas Chromatography (PCGC). The insights gained by these investigations are discussed in detail in the following chapters. The common thread between the three chapters is that the source of organic matter, the rate at which it is delivered to marine sediments and the depositional environment, all set the stage for kerogen formation and eventual petroleum generation.
Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution May 1996
Showing items related by title, author, creator and subject.
Aging of marine organic matter during cross-shelf lateral transport in the Benguela upwelling system revealed by compound-specific radiocarbon dating Mollenhauer, Gesine; Inthorn, Maik; Vogt, Thomas; Zabel, Matthias; Sinninghe Damste, Jaap S.; Eglinton, Timothy I. (American Geophysical Union, 2007-09-18)Organic matter accumulation and burial on the Namibian shelf and upper slope are spatially heterogeneous and strongly controlled by lateral transport in subsurface nepheloid layers. Much of the material deposited in ...
Griffith, David R.; Martin, William R.; Eglinton, Timothy I. (2010-08)Long-term carbon cycling and climate change are strongly dependent on organic carbon (OC) burial in marine sediments. Radiocarbon (14C) has been widely used to constrain the sources, sinks, and processing of sedimentary ...
Transfer of organic carbon through marine water columns to sediments – insights from stable and radiocarbon isotopes of lipid biomarkers Wakeham, Stuart G.; McNichol, Ann P. (Copernicus Publications on behalf of the European Geosciences Union, 2014-12-10)Compound-specific 13C and 14C compositions of diverse lipid biomarkers (fatty acids, alkenones, hydrocarbons, sterols and fatty alcohols) were measured in sinking particulate matter collected in sediment traps and from ...