Chemical composition of the graphitic black carbon fraction in riverine and marine sediments at sub-micron scales using carbon X-ray spectromicroscopy
Haberstroh, Paul R.
Brandes, Jay A.
Dickens, Angela F.
Cody, George D.
MetadataShow full item record
The chemical composition of the graphitic black carbon (GBC) fraction of marine organic matter was explored in several marine and freshwater sedimentary environments along the west coast of North America and the Pacific Ocean. Analysis by carbon x-ray absorption near edge structure (C-XANES) spectroscopy and scanning transmission x-ray microscopy (STXM) show the GBC-fraction of Stillaguamish River surface sediments to be dominated by more highly-ordered and impure forms of graphite, together forming about 80% of the GBC, with a smaller percent of an aliphatic carbon component. Eel River Margin surface sediments had very little highly-ordered graphite, and were instead dominated by amorphous carbon and to a lesser extent, impure graphite. However, the GBC of surface sediments from the Washington State Slope and the Mexico Margin were composed almost solely of amorphous carbon. Pre-anthropogenic, highly-oxidized deep-sea sediments from the open Equatorial Pacific Ocean contained over half their GBC in different forms of graphite as well as highly-aliphatic carbon, low aromatic/highly-acidic aliphatic carbon, low aromatic/highly aliphatic carbon, and amorphous forms of carbon. Our results clearly show the impact of graphite and amorphous C phases in the BC fraction in modern riverine sediments and nearby marine shelf deposits. The pre-anthropogenic Equatorial Pacific GBC fraction is remarkable in the existence of highly-ordered graphite.
Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 70 (2006): 1483-1494, doi:10.1016/j.gca.2005.12.001.
Showing items related by title, author, creator and subject.
Dilling, Lisa; Doney, Scott C.; Edmonds, Jae; Gurney, Kevin R.; Harriss, Robert; Schimel, David S.; Stephens, Britton B.; Stokes, Gerald (Annual Reviews, 2003-08-14)Agriculture and industrial development have led to inadvertent changes in the natural carbon cycle. As a consequence, concentrations of carbon dioxide and other greenhouse gases have increased in the atmosphere and may ...
The marine inorganic carbon system along the Gulf of Mexico and Atlantic coasts of the United States : insights from a transregional coastal carbon study Wang, Zhaohui Aleck; Wanninkhof, Rik; Cai, Wei-Jun; Byrne, Robert H.; Hu, Xinping; Peng, Tsung-Hung; Huang, Wei-Jen (Association for the Sciences of Limnology and Oceanography, 2013-01)Distributions of total alkalinity (TA), dissolved inorganic carbon (DIC), and other parameters relevant to the marine inorganic carbon system were investigated in shelf and adjacent ocean waters during a U.S. Gulf of Mexico ...
Variability in the carbon isotopic composition of foliage carbon pools (soluble carbohydrates, waxes) and respiration fluxes in southeastern U.S. pine forests Mortazavi, Behzad; Conte, Maureen H.; Chanton, Jeffrey P.; Weber, John C.; Martin, Timothy A.; Cropper, Wendell P. (American Geophysical Union, 2012-04-19)We measured the δ13C of assimilated carbon (foliage organic matter (δCOM), soluble carbohydrates (δCSC), and waxes (δCW)) and respiratory carbon (foliage (δCFR), soil (δCSR) and ecosystem 13CO2 (δCER)) for two years at ...