Characterizing flint outcrops in secondary position

A study case: Th e Euphrates terraces and their exploitation during the 8TH-7TH millennia cal BC

Ferran Borrell 1

Introduction

The middle Euphrates valley is, in the geographical sense, the region stretching between the actual village of Adiyaman (Turkey) and confluence of the Euphrates with the Khabour river in Syria (Kuzucuo ™ lu

et al. 2004). All along the river, several dams have been built. The most recent ones are the dams of Tichrine (Syria) and Carchemish (Turkey). As a result of the constructions, excavations were initiated at Tell Halula (Molist 1996; SAPPO 2007) and Akarçay Tepe (Balkan-Atlı et al. 1999; Arimura et al. 2000; Özbasaran, Molist 2006). The rising of water levels has modified the course of the river and flooded part of the terraces, resulting in the loss of information regarding the evolution of the river valley formation process. In spite of that, some geomorphologists and geologists have been studying the terraces of the Euphrates for decades, working as much in Syria as in Turkey (Minzoni-Deroche, Sanlaville 1988, 2004; Geyer, Besançon 1997; Kuzucuo ™ lu et al. 2004). The results of these works are different sequences from terraces dated from the Final Pleistocene to the Middle Age, being able to establish successive phases of stabilization, deposition and erosion (Kuzucuo ™ lu et al. 2004). Within these terraces there is a great amount and variety of nodules of siliceous rocks. These nodules have been transported several hundreds of kilometres from their context of original genesis. The nodules of flint display almost all the exterior surface completely eroded, rolled and without any remain of its bedrock. The terraces became an important source of raw materials for the Neolithic communities settled all along the course of the Euphrates river. In spite of that, researchers have often paid less attention to flint coming from secondary position than to primary outcrops. The composition characterization of secondary deposits is a specific problem dealt with by a limited number of researchers (Ray 1982; Howard 1993; Shelley 1993; Risch 1995). The exploitation of flint coming from the Euphrates terraces throughout the prehistory has been considered by many of the archaeologists and geologists who study both the lithic industries from the sites located along the river valley and the artefact assemblages within the terraces (Minzoni-Deroche, Sanlaville 1988; Nishiaki 2000; Abbès 2003; Sanlaville 2004; Copeland 2007). Some studies have recognized a patterned use of the fluviatile pebbles and cobbles of flint, but the identification and characterization of the different varieties of flint found on the terraces have only been done through macroscopic observation, while the use of petrography and other analysis to characterize the primary outcrops starts to be widely extended in Near East (Saito, Tiba 1978; Borrell 2005; Long, Julig 2007; Julig et al. 2007; Doherty and Milic, in press).

This way there is still a lack of information about the flint varieties transported by the river and the different