Neolithic Tar

Birch bark tar has been identified in numerous investigations of prehistoric samples, as residues of hafting on stone tools, as visible surface deposits on pottery vessels and as isolated finds, sometimes displaying clear evidence 

The apparent deliberate selection and preparation of certain resources over others (birch bark tar over softwood products) is repeated throughout later European prehistory. Whilst we lack systematic comparative surveys of the physical properties of resin, heated wood and bark products, and bitumen, both choice and preference were being expressed. Yet, even if we had data of this nature, other factors are likely to have come into play. The ability to transform natural materials (such as wood or bark) into discrete organic substances then subject to myriad uses (hafting of tools and weapons just happens to be the most visibly persistent role) would have had a dramatic impact on those who made these substances. 

Boeda et al. (1996) identified bitumen on a flint scraper and a Levallois flake, discovered in Mousterian levels (about 40 000 BP) at the site of Umm el Tlel in Syria. The occurrence of polyaromatic hydrocarbons such as fluoranthene, pyrene, phenanthrenes and chrysenes suggested that the raw bitumen had been subjected to high temperature. The distribution of the sterane and terpane biomarkers in the bitumen did not correspond to the well-known bitumen occurrences in these areas. In other studies of bitumen associated with a wide variety of artefacts of later date, especially from the 6th Millennium BC onwards, molecular and isotopic methods have proved successful in recognizing different sources of bitumen enabling trade routes to be determined through time (Connan et al., 1992 Connan and Deschesne, 1996 Connan, 1999 Harrell and Lewan, 2002). 

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