Characterization and Distribution of Pyrogenic Carbon in a Fraction of Archaeological Black Earth from Caxiuanã

Journal of the Brazilian Chemical Society

Milena Carvalho Moraes¹  Vanda Porpino Lemos¹  Dorsan Santos Moraes¹  Cláudio Nery Lamarão Moraes¹ 

关键词: pyrogenic carbon;    black earth;    O/C atomic ratio;    condensed combustion;   

DOI  :  10.5935/0103-5053.20150140

来源: SciELO

【 摘 要 】

This study aims to determine the atomic ratio of O/C in an archaeological black earth (ABE) profile of the Ilha de Terra site, a region of Caxiuanã in the Pará State, Brazil, to determine the types of pyrogenic carbon (PyC) particles and to infer the source of biomass and burning temperature necessary to produce the PyC. The O/C ratios were monitored using scanning electron microscopy combined with energy dispersive spectroscopy (SEM/EDS). The results indicated atomic ratios for clay, silt and fine sand fractions that were between those registered for the PyC particles types: condensed combustion (CC) (0.09, 0.1, 0.13), charcoal (0.32, 0.31, 0.34) and char (0.43, 0.45, 0.52). CC is the predominant type of particle found because of the high firing temperature (> 350 °C), which is consistent with the probable biomass sources of wood, cellulose and lignin.

【 授权许可】

CC BY   
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