A 36 ka environmental record in the southern tropics : Lake Tritrivakely (Madgascar)

Un enregistrement de l'environnement depuis 36 ka en zone tropicale sud : le lac Tritrivakely (Madagascar)

Françoise Gasse (1) , Elsa Cortijo (2) , Jean-Robert Disnar (3) , Luc Ferry , Elisabeth Gibert , Catherine Kissel (2) , Fatima Laggoun-Défarge (3) , Elisabeth Lallier-Vergès (3) , Jean-Claude Miskovsky , Bruno Ratsimbazafy , Flavien Ranaivo , Laurent Robinson , Piotr Tucholka , Jean-Luc Saos , Abdel Sifeddine (4) , Maurice Taieb , Elise van Campo , David Williamson

1 CEREGE - Centre européen de recherche et d'enseignement des géosciences de l'environnement
2 Centre des Faibles Radioactivités
3 ISTO - Institut des Sciences de la Terre d'Orléans
4 PALEOTROPIQUE - Paléo-environnements tropicaux et variabilité climatique

The upper 13 m of a 40 m-long sedimentary profile core taken in a crater lake on the Malagasy Plateau reveals 36,000 yrs of hydroclimatic evolution. A shallow lake occupies the core site from ≃35 to ≃19 ka BP under climatic conditions cooler than today. The water table is very low and biological productivity extremely reduced during the Last Glacial Maximum. A large warming was initiated at ≃14.5 ka BP. The modern bog establishes about 4 ka ago

Mots clés: Malagasy Republic; lake sediments; cores; drilling; paleoenvironment; paleoclimatology; paleotemperature; paleohydrology; warming; peat bogs; tropical environment; upper Quaternary; absolute age; C-14; stable isotopes; C-13; Indian Ocean Islands

Domaines: Géochimie; Géophysique [physics.geo-ph]

Françoise Gasse, Elsa Cortijo, Jean-Robert Disnar, Luc Ferry, Elisabeth Gibert, et al.. A 36 ka environmental record in the southern tropics : Lake Tritrivakely (Madgascar). Comptes rendus de l’Académie des sciences. Série IIa, Sciences de la terre et des planètes, 1994, 318, pp.1513-1519. ⟨hal-00122534⟩