A geochemical study of bituminous mixtures from Failaka and Umm an‐Namel (Kuwait), from the Early Dilmun to the Early Islamic period

Abstract

This paper is the last in a series presenting geochemical analyses of fragments of bituminous mixtures excavated from archaeological sites in Kuwait. The first was devoted to bituminous boat remains from the Ubaid‐related Neolithic site of H3, As‐Sabiyah, while the second dealt with bituminous amalgams from the Partho‐Sasanian site of cAkkaz, a former island now joined to the south side of Kuwait Bay. This, the third, refers to bitumen‐bearing samples from two other islands, Failaka and Umm an‐Namel, and covers a time span including the Early Dilmun period, the Kassite period and the Hellenistic to Early Islamic periods. The composition of the bituminous amalgams was studied in detail. The proportions of soluble and insoluble organic matter as well as vegetal organic matter were evaluated. Mineralogical composition by X‐Ray diffraction and thin‐section analysis was used to estimate the mineral input in the bituminous mixtures. It can be confirmed that the recipes used in the preparation of these bituminous amalgams comply with those traditionally used in antiquity, as seen at many sites in Mesopotamia and the Gulf. Analysis of the soluble organic matter, and especially its ‘‘saturates’’ fraction, provided sterane and terpane distributions and the measurement of diagnostic molecular ratios. These data, complemented by the isotopic composition of asphaltenes, allowed the identification of the sources of the bitumen, by calibration with numerous references from Iran and northern Iraq (oil seeps, bitumen from archaeological sites). It was established that the bitumen from Failaka and Umm an‐Namel was mainly imported from central Iraq (Hit‐Abu Jir) and northern Iraq (around Mosul). One sample of oil‐stained sand, dating to the Early Dilmun period, originated from Burgan and thus documents small‐scale imports from inland Kuwait. These results, and those of previous analyses, agree with the geopolitical context of the Early Dilmun, Kassite and Hellenistic periods, and the maritime trade routes that linked Mesopotamia to the settlements of the Gulf and beyond. The paper concludes with an overview of recent bitumen provenance analyses, and discerns chronological patterns in the distribution of Iraqi and Iranian bitumen in the Gulf and Indian Ocean, from the Neolithic to the Islamic periods.