Skip to Main content Skip to Navigation
Theses

Enregistrement des variations paléoenvironnementales depuis 20000 ans dans le Nord Est du Brésil (Lac Caço) par les triterpènes et autres marqueurs organiques.

Abstract : This study aims at identifying new proxies for past climate changes in the organic matter (OM) contained in lacustrine sediments. The selected study site is Lake Caço, located in a climatically sensible zone, where the Inter Tropical Convergence Zone presently enters the continent. Bulk characterization of the organic content of sediments collected on a 6m core attest to a higher plant origin of this OM. Strong differences in the preservation state of this OM testimony to contrasting climatic conditions that occurred since the end of Last Glacial Maximum. New biomarkers, specific of higher plants (onocerane I, pentacyclic triterpene methyl ethers), have been identified. These molecules testimony to the botanical associations that developed in the catchment area and to the physico-chemical conditions that prevailed at time of sediment deposition.
Document type :
Theses
Complete list of metadatas

Cited literature [114 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00002942
Contributor : Nathalie Pothier <>
Submitted on : Wednesday, June 4, 2003 - 8:39:54 AM
Last modification on : Friday, October 23, 2020 - 4:56:47 PM
Long-term archiving on: : Friday, April 2, 2010 - 8:09:18 PM

Identifiers

  • HAL Id : tel-00002942, version 1

Citation

Jérémy Jacob. Enregistrement des variations paléoenvironnementales depuis 20000 ans dans le Nord Est du Brésil (Lac Caço) par les triterpènes et autres marqueurs organiques.. Géochimie. Université d'Orléans, 2003. Français. ⟨tel-00002942⟩

Share

Metrics

Record views

469

Files downloads

1077