Séminaire
Diagenesis in sediments with deep oxygen penetration: Lessons from Lake Superior and comparisons with marine systems
Date
le 29-05-2012 à 10:45Lieu Salle Stendhal, DGO, Bâtiment B18
Intervenant(s) Sergei KATSEV, Professeur invité à EPOC, Large Lakes Observatory, University of Minnesota Duluth, USA |
Résumé
Past studies in marine sediments have identified relationships between the rates of organic carbon mineralization and characteristics such as water depth, sedimentation rate, and exposure to oxygen. In contrast, few such studies have been done in lakes. Using Lake Superior as an example, I will describe the sediment dynamics of carbon and oxygen and compare them with their marine counterparts. Particular focus will be on sediments with deep (several cm) penetration of oxygen, as the depth of redox boundary in such sediments is highly variable and sensitive to seasonal and longer-term variations. The obtained relationships for the decrease in organic carbon reacitivity with age and the mobility of redox boundary are important for the interpretations of paleolimnological records.