Spatial sedimentary distribution, seasonality and the characteristics of organic matter on Fernando de Noronha insular shelf
| Autor: | Roberto Lima Barcellos, Liza Ellen Eurico de Oliveira, Manuel de Jesus Flores-Montes |
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| Jazyk: | angličtina |
| Předmět: | |
| Zdroj: | Brazilian Journal of Oceanography, Vol 66, Iss 1, Pp 131-156 |
| Druh dokumentu: | article |
| ISSN: | 1982-436X 1679-8759 |
| DOI: | 10.1590/s1679-87592018146206601 |
| Popis: | Abstract The present study was conducted in the Fernando de Noronha archipelago (4°S/32°W). The objective is the evaluation of the spatial distribution and seasonal variations in the sediments and sedimentary organic matter in the northern insular shelf of Fernando de Noronha ("Mar de Dentro"). Nineteen surface sediment samples were collected between December 2013, July 2014 and November 2014. The studied methods included analysis of the grain size, coarse fraction, morphoscopy, total organic matter content, calcium carbonate, organic carbon, total nitrogen, sedimentary phosphorus (organic, inorganic and total), elemental ratios (C/N, C/P) and stable isotopic ratios (δ13C-δ15N). The results allowed to infer that there is no seasonal variation in sediment distribution. Whereas, the shelf sediments present a calcareous sandy sedimentary cover (CaCO3≈ 88.3%), predominantly of well-sorted fine sands, with low organic matter content (TOM3.0%; TN>0.4%) of mixed origin (δ13C= -24.5 to -23.0%PDB), which were related to anthropogenic impacts and the biotic and abiotic local processes. |
| Databáze: | Directory of Open Access Journals |
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