HR: 0800h
AN: OS51B-05    [Abstracts]
TI: Variability of Total Organic Carbon and Nitrogen in Abyssal Sediments in the Gulf of Mexico
AU: * Garcia, F J
EM: franciscojavier_gv@yahoo.com.mx
AF: Instituto de Cincias del Mar y Limnologia, UNAM, Circuito Exterior, Mexico, D.F 04510, Mexico
AU: Escobar Briones, E
EM: escobri@mar.icmyl.unam.mx
AF: Instituto de Cincias del Mar y Limnologia, UNAM, Circuito Exterior, Mexico, D.F 04510, Mexico
AB: Marine sediments represent the largest reservoir of carbon on Earth and an important factor in climate change and allow us to understand the role of the deep sea sediments as a reservoir for the organic carbon and the chemical balance of nitrogen in the basin. This study determined the precision (CV < 3%) and accuracy (CV < 3%) of the elemental analysis carried out that described the variability of total organic carbon (TOC) and nitrogen from samples collected at 115 locations during several cruises in a depth interval of 1025 and 3725 m. The average values recorded for abyssal sediment samples in the SW Gulf of Mexico were 0.95% +/- 0.135% for TOC and 0.12% +/- 0.025% for N with a C/N ratio of 7.96 +/- 1.406. Only samples from chemosynthetic locations (i.e. Chapopote asphalt volcano) recorded S in 3.35% +/- 1.503%. The elemental composition of TOC and N is controlled by depth and follows a polynomial pattern; the C/N followed a sigmoid pattern and together with TOC varies with the distance to the coast and depth. The presence of topographic features in the seafloor influence the distribution of TOC and N.
DE: 4825 Geochemistry
SC: Ocean Sciences [OS]
MN: 2007 Joint Assembly