Abstract

Thirty-nine samples from the religious complex of Qâni’, which was excavated by the French Archaeological Mission, and two samples from a burnt-out warehouse in Sector VI, which was excavated by the Russian Archaeological Mission in Yemen, were investigated by screening geochemical techniques (Rock-Eval, dichloromethane extract, GC-MS of steranes and terpanes, carbon and deuterium isotopes of asphaltenes) completed by devoted GC-MS analyses in order to identify frankincense. Several types of frankincense (well preserved, thermally altered and carbonized), were identified. In addition sterane and terpane patterns reveal the occurrence of unexpected bitumen in potsherds. Bitumen samples were compared to some oil seeps and crude oils from Yemen but none of the potential sources showed geochemical characteristics matching the bitumen from Qâni’. The occurrence of 18?(H)-oleanane in an ozokerite suggests a possible origin from Khuzistan or Fars in Iran. A specific flowchart, giving access to the predominant triterpenic biomarkers, namely structures with oleanane, ursane and lupane skeletons allowed excluding Boswellia frereana as the frankincense present in the sample set. Various states of thermal degradation of frankincense were found among the frankincense samples of the religious complex through the occurrence of functionalized molecule which were formed by thermal processes. 

Keywords

Bitumen, frankincense, archaeological samples, crude oils, natural asphalts, gas chromatography-mass spectrometry, rock-Eval, Yemen, religious complex, Archaeological Mission, warehouses, archaeological samples