Production and use of birch bark tar at the Neolithic pile-dwelling of Palu di Livenza (North-Eastern Italy) revealed by X-ray computed micro-tomography and synchrotron Fourier-transform infrared spectroscopy

Recent excavations at Palu di Livenza (northeastern Italy) revealed a multiphase Neolithic pile dwelling dated between ca. 4,300/4200 and 3,600 cal BC. Three lumps with teeth imprints and a larger amorphous piece from the Late Neolithic layers have been studied by X-ray computed micro-tomography (microCT) and synchrotron Fourier-transform infrared spectroscopy (FTIR). FTIR spectra match well that of birch bark tar and microCT of the larger piece has revealed a rolled-up structure likely corresponding to bark rolls. The lumps of birch pitch were probably chewed to soften the tar prior to be used as hafting adhesive or therapeutic substance. The rolled-up inner structure of the larger piece and the remains of birch bark tar and abundant charcoals on its surface suggest it probably corresponds to a rare waste product from allothermic tar production.

Automated summary

Recent excavations at Palu di Livenza in northeastern Italy uncovered a Neolithic pile dwelling dating back to approximately 4,300/4200 to 3,600 cal BC. X-ray computed micro-tomography and synchrotron Fourier-transform infrared spectroscopy were used to analyze three lumps with teeth imprints and a larger amorphous piece from the Late Neolithic layers. The analysis revealed that the lumps were made of birch pitch, which was possibly chewed to soften the tar for use as hafting adhesive or therapeutic substance. The larger piece showed a rolled-up inner structure and contained remnants of birch bark tar and charcoal, suggesting it may be a rare waste product from tar production.