Schmidt, Frauke; Hinrichs, Kai-Uwe; Elvert, Marcus (2010): Sources, transport, and partitioning of organic matter from 40 surface sediment samples at the NW Iberian margin. PANGAEA, https://doi.org/10.1594/PANGAEA.733992, Supplement to: Schmidt, F et al. (2010): Sources, transport, and partitioning of organic matter at a highly dynamic continental margin. Marine Chemistry, 118(1-2), 37-55, https://doi.org/10.1016/j.marchem.2009.10.003
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Continental shelves play a major role as transition zone during transport of multiply-sourced organic matter into the deep sea. In order to obtain a comprehensive understanding of the origin and fractionation processes of organic matter at the NW Iberian margin, 40 surface sediment samples were analyzed for a structurally diverse range of lipid biomarkers, lignin phenols, grain size distribution, organic carbon content (TOC), its stable carbon isotopic composition (d13CTOC), and the organic carbon to nitrogen ratio (TOC/TN). The biomarker inventory reflected a heterogeneous mixture of organic matter from various marine and terrestrial sources. Soil- and vascular plant-derived continental organic matter, indicated by lignin phenols and plant-derived triterpenoids, was primarily associated with the silt fraction and transported by river run-off. The spatial distribution patterns of higher plant-derived waxes, long-chain n-alkanes, n-alcohols, and n-fatty acids suggested distinct different transport mechanisms and/or sources. The branched tetraether index, a molecular proxy expressing the relative abundance of branched dialkyl tetraethers vs. crenarchaeol and considered to signal soil-derived organic matter, was not as sensitive as the other molecular indicators in detecting continental organic matter. Hydrodynamic sorting processes on the shelf resulted in a separation of different types of terrestrial organic matter; grass and leaf fragments and soil organic matter were preferentially transported offshore and deposited in areas of lower hydrodynamic energy. Algal lipid biomarker distributions indicated a complex community of marine plankton contributing to organic matter. Spatial and seasonal patterns of phytoplankton growth primarily controlled the distribution of algal organic matter components. The interplay of all of these processes controls production, distribution, and deposition of organic matter and results in three distinct provinces at the Galicia-Minho shelf: (I) fresh marine organic matter dominated the inner shelf region; (II) high inputs of terrestrial organic matter and high TOC content characterized the mid-shelf deposited mudbelt; (III) lower concentrations of relatively degraded organic matter with increased proportions of refractory terrestrial components dominated the outer shelf and continental slope.
Median Latitude: 42.263996 * Median Longitude: -9.234502 * South-bound Latitude: 41.551000 * West-bound Longitude: -9.760333 * North-bound Latitude: 42.866660 * East-bound Longitude: -8.866660
Date/Time Start: 2006-08-15T00:00:00 * Date/Time End: 2006-09-03T11:59:00
GeoB11001-1 * Latitude: 42.249889 * Longitude: -9.083333 * Date/Time: 2006-08-20T06:09:00 * Elevation: -136.0 m * Campaign: POS342 * Basis: Poseidon * Method/Device: Giant box corer (GKG) * Comment: empty
GeoB11002-1 * Latitude: 42.166583 * Longitude: -8.990111 * Date/Time: 2006-08-22T06:14:00 * Elevation: -111.0 m * Campaign: POS342 * Basis: Poseidon * Method/Device: Giant box corer (GKG) * Comment: 32 cm, 4xL, 4xSurface, pore water
Datasets listed in this publication series
- Schmidt, F (2010): (Table 1) Location and bulk properties of samples from the NW Iberian margin and adjacent rivers. https://doi.org/10.1594/PANGAEA.733799
- Schmidt, F (2010): (Table 3) Concentrations of lipid biomarkers and lignin-derived phenols in all samples from the mudbelt, inner and mid-shelf, outer shelf and continental slope. https://doi.org/10.1594/PANGAEA.733879
- Schmidt, F (2010): (Table 4) Vegetation and soil ratios in all analyzed surface sediments from theNW Iberian margin and source rivers. https://doi.org/10.1594/PANGAEA.733889
- Schmidt, F (2010): (Table 5) Biomarker degradation ratios at the NW Iberian margin and source rivers. https://doi.org/10.1594/PANGAEA.733989