Relations between organic and terrigenous matter deposition in Holocene fluvial sediments: heterodox observations and conclusions.

Jean-Jacques Macaire (1) , Christian Di Giovanni (2) , Florent Hinschberger (1)

1 GéEAC EA 2100 - Géologie des environnements aquatiques continentaux
2 ISTO - Institut des Sciences de la Terre d'Orléans

Accumulation of organic matter in fens of fluvial valleys is often related to a low terrigenous matter delivery and to palaeoenvironmental conditions inducing low mechanical erosion. These assumptions come from the interpretation of contents in organic (MO) and mineral (MM) matters in sediments, expressed in percents, and then exactly anticorrelated. Calculation of mass accumulation rates of MO (TaMO) and MM (TaMM), expressed in g m−2 yr−1, shows that TaMO and TaMM generally are not anticorrelated and that high values of TaMO and TaMM could appear simultaneously. That expression of MO and MM accumulation makes it possible to precise the climatic and human impact on sedimentation.

Mots clés: Holocene; Peat; Terrigenous sediments; Fluvial environment; Accumulation rates; Paris Basin; France

Domaines: Interfaces continentales, environnement; Milieux et Changements globaux

Jean-Jacques Macaire, Christian Di Giovanni, Florent Hinschberger. Relations between organic and terrigenous matter deposition in Holocene fluvial sediments: heterodox observations and conclusions.. Comptes Rendus Géoscience, 2005, 337, pp.8, 735-744. ⟨10.1016/j.crte.2005.03.017⟩. ⟨hal-00023442⟩