Chemical evaluation of carbonized logs from Araucariaceae species: characterization of materials associated to multivariate analysis for environmental inferences

The main objective of this study was to develop a methodology to evaluate, by physical and chemical methods, artificially charred logs from three species of Araucariaceae, and compare them fossil charcoal collected in the Faxinal and Belvedere outcrops for possible paleoenvironmental inferences. The species studied were Araucaria angustifolia, Araucaria bidwillii and Araucaria columnaris. For fossil charcoal analyses we used samples from the Mina do Faxinal and samples from the Curva do Belvedere Outcrop. The carbonization process from species of Araucariaceae were Thermogravimetric Analysis (TGA) associated to the techniques of Fourier Transform Infrared Spectroscopy (FTIR) and multivariate analysis. The Principal Component Analysis (PCA) showed that it is possible to describe 90,9% of the data, grouping the samples into two main clusters. Both samples of fossil charcoal from Belvedere and Faxinal showed charring characteristics above 400ºC. Results showed that technical associations, such as TGA, FTIR and multivariate analysis may help to characterize the natural carbonization process and contribute to important paleoenvironmental and archaeological information and inferences.