Publications des scientifiques de l'IRD

Valdes J., Sifeddine Abdelfettah, Lallier-Vergès E., Ortlieb Luc. (2004). Petrographic and geochemical study of organic matter in surficial laminated sediments from an upwelling system (Mejillones del Sur Bay, Northern Chile). Organic Geochemistry, 35, p. 881-894.

Titre du document
Petrographic and geochemical study of organic matter in surficial laminated sediments from an upwelling system (Mejillones del Sur Bay, Northern Chile)
Année de publication
2004
Type de document
Article référencé dans le Web of Science WOS:000222547100007
Auteurs
Valdes J., Sifeddine Abdelfettah, Lallier-Vergès E., Ortlieb Luc
Source
Organic Geochemistry, 2004, 35, p. 881-894
A study of recent laminated sediments, accumulated in the oxygen minimum zone of Mejillones Bay (Northern Chile), shows that the organic matter is autochthonous and deposited under varying oceanographic conditions. Sedimentary units dominated by light laminations have low values of total organic carbon, total nitrogen and sulphur, and Chaotoceros content, coupled with high values of yellow amorphous organic matter. These were deposited under conditions of low primary productivity, favoring the recycling of the major part of metabolizable organic matter in the water column, and the accumulation only of non-metabolizable organic matter in the bottom sediments. In contrast, a unit rich in dark laminations with high values of total organic carbon, total nitrogen and sulphur, shows high values of brown and black AOM, and Chaetoceros content. This sedimentary unit reflects increased flocculation of organic particles during a period of high productivity and fast transit of organic material through the column water, thus diminishing the recycling of metabolizable organic matter and its accumulation with non-metabolizable organic matter in the sediments. Finally, a unit characterized by presence of both light and dark laminations was formed by abrupt alternations of the two oceanographic states described previously.
Plan de classement
Sciences du milieu [021] ; Géologie et formations superficielles [064]
Description Géographique
CHILI
Localisation
Fonds IRD [F B010067886]
Identifiant IRD
PAR00003013
Contact