Surface sediments were collected in a transect from the Amazon river delta to open marine sites in the north Atlantic Ocean in order to characterize spatial contrasts in the deposited organic carbon (OC), allowing to uncover the role of the river plume on the sedimentation of OC. Analysis of isoprenoidal and branched glycerol dialkyl glycerol tetraethers (GDGTs), lignin phenols, fatty acids, n-alkanes and bulk parameters were performed to characterize the sedimentary OC. An end-member approach based on biomarkers (lignin phenols and GDGTs), and the stable carbon isotopic composition of bulk organic carbon (δ¹³C_OC), was used to estimate the fraction of marine (OC_mar) and continental sources (OC_cont) of sedimentary organic carbon. Similar estimates based on lignin phenols were obtained and indicates that the OC_cont was on average 30 ± 37%; based on the GDGTs it was 29 ± 35% while based on the δ¹³C_OC it was 30 ± 32%. The OC content of the surface sediments remained relatively constant from the delta to the marine sites northward (ca. 0.6%) but the fractions of continental and marine OC were variable. In the deltaic region, OC_cont was ca. 84%, while in the open marine sites, OC_mar was ca. 86%. In the stations southward the delta, the OC content was about 0.03% with high OC_mar and low OC_cont, which indicates a low influence of the river plume on this location. The accumulation rates of OC_cont and OC_mar were estimated and showed that both were higher in the deltaic region in comparison to the marine sites. The results suggested that only 10–15% of the OC_cont is deposited offshore and that river plume conditions stimulated primary production and, thus, ultimately the sedimentation of OC_mar in the continental shelf and offshore sediments. Finally, our estimates showed that the Amazon River Delta has an accumulation rate above the global average and the material transported horizontally by the river plume fuels the primary production in adjacent areas, which improves the relevance of the Amazon continental shelf to the global carbon budget.

从亚马逊河三角洲的一个样带中收集地表沉积物，开辟了北大西洋北部的海洋站点，以表征沉积有机碳（OC）的空间差异，从而揭示了河羽在OC沉积中的作用。 。对类异戊二烯和支链甘油二烷基甘油四醚（GDGTs），木质素酚，脂肪酸，正构烷烃和体积参数进行了分析，以表征沉积OC。根据生物标志物（木质素酚和GDGTs）的端部件的方法，以及散装有机碳的稳定碳同位素组成（δ ¹³ C ^ _OC），来估计船舶（OC的分数_擦伤）和大陆源（OC_续）的沉积有机碳。得到了基于木质素酚的类似估计值，表明OC _cont平均为30±37％。基于所述GDGTs它是29±35％，而基于所述δ ¹³ Ç _OC它是30±32％。从三角洲到北端海域，表层沉积物的OC含量保持相对恒定（约0.6％），但大陆和海洋OC的比例却是可变的。在三角洲地区，OC _cont约为。84％，而在开放的海洋场所中，OC _mar大约是3月。86％。在站向南增量，所述OC含量为约0.03％高OC_擦伤和低OC_续，表明河流羽流对该位置的影响较小。估算了OC _cont和OC _mar的累积速率，表明与沿海地区相比，三角洲地区的oc含量更高。结果表明，只有OC _cont的10％到15％沉积在海上，而河羽条件刺激了初级生产，因此最终导致了OC _mar的沉积。在大陆架和近海沉积物中。最后，我们的估计表明，亚马逊河三角洲的蓄积率高于全球平均水平，河羽水平输送的物质为邻近地区的初级生产提供了燃料，这提高了亚马逊大陆架与全球碳预算的相关性。