Organic geochemistry of submarine canyons: The Portuguese Margin
Kiriakoulakis, K.; Blackbird, S.; Ingels, J.; Vanreusel, A.; Wolff, G.A. (2011). Organic geochemistry of submarine canyons: The Portuguese Margin. Deep-Sea Res., Part 2, Top. Stud. Oceanogr. 58(23-24): 2477-2488. dx.doi.org/10.1016/j.dsr2.2011.04.010 In: Deep-Sea Research, Part II. Topical Studies in Oceanography. Pergamon: Oxford. ISSN 0967-0645; e-ISSN 1879-0100, more |  |
| Keywords | Biomarkers
Chemical compounds > Organic compounds > Lipids
Chemistry > Geochemistry
Organic matter
Preservation
Topographic features > Submarine features > Continental margins
Topographic features > Submarine features > Submarine canyons
ANE, Portugal [Marine Regions]
Marine/Coastal | | Author keywords | Portuguese Continental Margin; Organic geochemistry; Submarine canyons;Organic matter preservation; Terrestrial organic matter; Lipidbiomarkers |
| Authors | | Top | - Kiriakoulakis, K.
- Blackbird, S.
- Ingels, J., more
| | |
| Abstract | The organic geochemistry of the Portuguese Margin of the North-Eastern Atlantic Ocean reveals a highly heterogeneous environment that is strongly influenced by canyons that incise the continental margin. Suspended particulate organic matter (sPOM) is funnelled through the canyons to the deep sea, particularly in the Nazaré Canyon where there are high concentrations of sPOM even at >2000 m water depth. The nature of the sPOM through the water column varies, with that transported through the canyons having higher contributions of terrestrial organic matter (higher C/N and larger contribution of land plant-derived lipids) than sPOM in overlying waters and close to the seafloor on the adjacent slope. Zooplankton-derived lipids dominate sPOM associated with the upper and lower boundaries of the Mediterranean Overflow Water (MOW~600 and 1500 m, respectively). Canyon sediments are enriched in organic carbon when compared to slope sediments, but sedimentary organic matter also appears to derive from multiple sources and undergoes significant alteration prior to deposition. On the open slope, low sedimentation rates and long oxygen exposure times lead to intensive oxidation of organic matter. |
|
