Intensifying weathering and land use in Iron Age Central Africa.
About 3000 years ago, a major vegetation change occurred in Central Africa, when rainforest trees were abruptly replaced by savannas. Up to this point, the consensus of the scientific community has been that the forest disturbance was caused by climate change. We show here that chemical weathering in Central Africa, reconstructed from geochemical analyses of a marine sediment core, intensified abruptly at the same period, departing substantially from the long-term weathering fluctuations related to the Late Quaternary climate. Evidence that this weathering event was also contemporaneous with the migration of Bantu-speaking farmers across Central Africa suggests that human land-use intensification at that time had already made a major impact on the rainforest.
Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Unité de Recherche Géosciences Marines, F-29280 Plouzané, France. gbayon@ifremer.fr
Germain
G
Bayon
Bernard
B
Dennielou
Joël
J
Etoubleau
Emmanuel
E
Ponzevera
Samuel
S
Toucanne
Sylvain
S
Bermell
D000350:Africa, Central; D000383:Agriculture / Q000266:history*; D000535:Aluminum / Q000032:analysis; D057231:Climate Change; D003247:Conservation of Natural Resources; D004641:Emigration and Immigration / Q000266:history; D019015:Geologic Sediments / Q000737:chemistry*; D055593:Geological Phenomena; D006195:Hafnium / Q000032:analysis; D049690:History, Ancient; D006802:Human Activities; D006801:Humans; D009354:Neodymium / Q000032:analysis; D006109:Poaceae; D011188:Potassium / Q000032:analysis; D014197:Trees
D009354:Neodymium; D000535:Aluminum; D011188:Potassium; D006195:Hafnium