Conifer tar on the keel and hull planking of the Ma'agan Mikhael Ship (Israel, 5th century BC): identification and comparison withnatural products and artefacts employed in boat construction

The Ma'agan Mikhael shipwreck was discovered in 1985 in shallow waters of the Mediterranean coast of Israel. The ship was dated to 500 BC. Resin-like organic matter, which was applied to the ship's timbers was analysed for biomarkers (terpenoids in particular) by various organo-geochemical techniques, such as MPLC, GC and GC-MS. For comparison, samples of recent conifer resins as well as tars from other ancient boats from Marseille, Chalon-sur-Saone and a 16th century ship from France, were analysed. The results show that the Ma'agan Mikhael material is a conifer resin that has undergone thermal treatment and should be properly referred to as 'tar' or 'pitch'. Similar results were obtained for the other ship-derived material from Chalon-sur-Saone. We suggest, therefore, that the term 'resin' should not be employed, as is commonly done, to describe materials, which were used as protective cover on ship timbers or as caulking material, unless chemical analysis indicate lack of thermal treatment. (C) 2003 Elsevier Science Ltd. All rights reserved.