25th International Meeting on Organic Geochemistry IMOG 2011

P-129
Characterisation of antique organic adhesives by GC-MS
Armelle Charrié-Duhaut 1 , Jacques Connan 1 , Pierre-Jean Texier 2 , Thomas Hauck 3 , Jean-
Marie Le Tensorer 3 , Céline Leprovost 4 , Mickaël Landolt 5
1 Laboratoire de Biogéochimie Moléculaire, Institut de Chimie de Strasbourg, UMR 7177, CNRS et Université
de Strasbourg, Strasbourg, France, 2 UMR 5199 - PACEA, CNRS et Université de Bordeaux1, Talence,
France, 3 Department of Prehistory, IPNA, University of Basel, Basel, Switzerland, 4 PAIR Pole d'Archéologie
Interdépartemental Rhénan, Sélestat, France, 5 PAIR Pole d'Archéologie Interdépartemental Rhénan UMR
7044, Sélestat, France (corresponding author:acharrie@unistra.fr)
The history of organic adhesives began
probably during the Middle Paleolithic and continued
until the development of synthetic substances.
Although organic glues are very sensitive towards
alteration, they may be preserved in various
archaeological contexts. These materials are the
witnesses of activities from past societies, of their
know-how and of available natural substances. They
can be characteristic of a population, an area or a
period. This paper presents the molecular and
isotopic study of three examples of glues illustrating
the high diversity of adhesives.
As in bio-organic geochemistry,
chromatographic techniques in tandem with mass
spectrometry and isotopic data (δ 13 C) supply a large
range of molecular tools to establish composition and
origin of archaeological organic materials and to
follow the molecular transformations induced by
alteration processes (biodegradation, abiotic
oxidation, evaporation,…). Each antique sample was
compared to its present-day reference: tar sands of
the Bichri desert, fresh Podocarpus bark, birch bark
tar freshly made.
a
b
Figure 1: Photographs of a) a Mousterian tool from
Hummal (Syria), b) a semi-cortical flake from
Diepkloof rock shelter (South Africa), c) a sickle from
Entzheim (France).
The first example corresponds to a
Mousterian tool (50000 BP at least) from the Hummal
Palaeolithic site in Syria. It presents a black macroresidue
on the underside, which has impregnated the
underlying sediment, leaving a clear imprint (Fig.1a).
Bitumen from the Bichri desert was clearly identified
by the distributions of hopanes and steranes, and
isotopic data. The Bichri massif was already identified
in 1996 as the source of bitumen stuck on Mousterian
c
tools excavated at Umm el Tlel (Syria, 70000 BP [1]).
Molecular differences among Hummal residue and
Bichri references are due to variations in degree of
alteration.
The second residue (Fig.1b) corresponds to
a fine deposit coating the cortical back of a semicortical
flake collected at Diepkloof Rock Shelter
(Western Cape, South Africa) from the upper part of
the Howiesons Poort complex (65000-55000 BC)
[2,3,4]. The GC-MS total ion current traces consist
mainly in linear and diterpenoid structures belonging
to the series of totarol and ferruginol. These
distributions are characteristic of Podocarpaceae
conifers. The degree of alteration of the
archaeological resin was studied by comparison with
fresh extract from South African Podocarpus. In
addition, Podocarpus wood remains were identified by
C. Cartwright among the charcoals from this site [5].
The last samples correspond to black matter
surrounding a lithic artefact, clearly drawing a sickle
(Entzheim, France). The sickle (Fig.1c) was found
near a skeleton in a necropolis dated from
Grossgartach period (4900-4700 BC).The results
show that birch bark tar, a triterpenoid adhesive made
by distillation of white birch bark, was used as glue.
This glue was already used during the Middle
Paleolithic period [6].
These works attest to the ability of our
ancestors, whatever the period considered, to use
surrounding natural products for practical use.
[1] Boëda et al. (2008) Antiquity 82, 853-861.
[2] Rigaud et al. (2006) C. R. Palevol. 5, 839-849.
[3] Texier et al. (2010) Proceedings of the National
Academy of Sciences 107, 6180-6185.
[4] Tribolo et al. (2008) J. Archaeol. Sci. 36, 730-739.
[5] Cartwright (2008) Interim report on DRS.
[6] Koller et al. (2001) European Journal of
Archaeology 4, 385-397.
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