C-14 AMS dating of fires in the central Amazon rain forest

Soil samples were collected in tierra firme upland and lowland areas of the Km 41 reserve near Manaus (20 degrees 30'S and 60 degreesW), in Central Br azilian Amazon, within a 1700 m transect, at eight different depth ranges, from surface to 100 cm. The highest charcoal concentrations were found at t he depth range of 20-50 cm. AMS radiocarbon dating of 31 samples were perfo rmed at the ANU. The ages of the charcoals were found to vary within the 13 0 to 2400 years BP range, mostly between 1200 and 1400 years BP, one of the known Holocene dry periods of the Amazon region. The results show that the fires have regional dimensions and are associated with climate regional ch anges. (C) 2000 Elsevier Science B.V. All rights reserved.