Evaluating levoglucosan as an indicator of biomass burning in Carajas, Amazonia: A comparison to the charcoal record

We report the use of levoglucosan, a novel molecular marker, to trace contr ibutions from vegetation combustion to sediments. Unlike other indicators u sed for the same purpose (e.g., retene, polynuclear aromatic hydrocarbons) levoglucosan is source specific and emitted in dominant amounts during the burning of any fuel containing cellulose. The combustion of other materials (i.e., fossil fuels) or biodegradation and hydrolysis of cellulose do not produce levoglucosan. In order to validate the application of this novel ma rker, levoglucosan was analyzed in a sediment core from a lake in Carajas ( southeastern Amazonia). This region presents a unique record of forest fire s over the last 7,000 years as indicated by charcoal analysis. The fires, w hich occurred in that area, could be characterized by using levoglucosan as a molecular marker. Similar reconstruction was possible by using charcoal as an indicator, which validates the application of levoglucosan for tracin g vegetation combustion in sediments. Both indicators enabled the recogniti on of major fires that occurred 700, 1200, 5000, and 7,000 years ago. Copyr ight (C) 2001 Elsevier Science Ltd.