Use of lipid biomarker patterns as a proxy of environmental variability in the coastal sedimentary record from the Gulf of Cádiz (SW Spain)

Surface sediments from the Gulf of Cádiz were analyzed using gas chromatography–mass spectrometry in order to estimate the origin, spatial distribution and degradation extent of the sedimentary organic matter (OM) from the inner continental shelf of the southwest Iberian Peninsula. A wide variety of lipid assemblages (n-alkanes, n-alkan-2-ones, n-aldehydes, n-fatty acids, α,ω-alkanedioic acids, diterpene resin acids and isoprenoids) were extracted with organic solvent and exhibited local variations depending on OM sources. Whereas the sediments located under the Guadiana river’s influence showed dominant continental derived, long chain (>C20) distributions, typically marine-derived short chain (