Ferrous Metal Production and Use at Saruq al-Hadid

Abstract

<p>Saruq al-Hadid is located in the northeastern part of the Rub' al Khali desert, 40 km from the coast and 60 km from the nearest mountains, on the southern fringes of the Emirate of Dubai, United Arab Emirates. The site is characterised by pervasive evidence of ritual activities, as well as the presence of thousands of archaeological artefacts, including more than 200 kg of ferrous remains, which sharply contrasts with the rarity of iron in the rest of Iron Age southeastern Arabia. All ferrous remains from the site are severely degraded, which presents major challenges for the use of standard approaches to their investigation. This PhD project adopts conventional methodological approaches to the corroded ferrous objects in order to address questions about ancient iron technology in the Near East, and its adoption by prehistoric Arabian societies. Ultimately, the research provides insight into the nature of degradation processes, artefact manufacturing techniques, evidence for the later re-processing / recycling of artefacts deposited at Saruq al-Hadid, and the provenance of the ferrous artefacts.</p> <p>In contrast to the majority of previous studies of Near Eastern iron objects, the advantage of the project's methodology is that it applies integrated archaeometric approaches incorporating multiple conventional invasive and non-invasive archaeometric techniques, to a statistically significant set of samples. The methodology incorporates a combination of Optical Microscopy, SEM-EDS, XRD and Micro Raman Spectroscopy to prove that the corrosion patterns observed in some artefacts were not merely caused by the natural corrosion process in the burial environment, but were heavily influenced by thermomechanical treatment, most likely occurring during re-processing / recycling. Additionally, Neutron Tomography, Optical Microscopy and slag inclusion analysis by SEM-EDS were used to investigate the forge-welding techniques used to fabricate the site's early iron objects. Finally, slag inclusion analysis by SEM-EDS and LA-ICP-MS, as well as microstructural investigation of iron slags, were used to address the question of iron provenance and to explore the possibility of local iron production.</p> <p>The results of these studies, when integrated with the broader archaeological evidence from the site, reveal that Saruq al-Hadid was a key node in an interconnected network of regional sites, receiving and possibly re-distributing large amounts of foreign and local commodities. The collected evidence also suggests that, given the availability of suitable raw materials and sufficient iron-making skills, good quality iron weapons and tools could have been produced in the ancient Near East already during the early Iron Age. However, iron smelting technology was not locally adopted at this time in southeastern Arabia. Instead, iron was mostly procured as finished products, via complex but as-yet-unclear economic and cultural connections, from western Iran. Thus, the material studies presented in this thesis further emphasise the vectors of cultural influence from western Iran to southeastern Arabia during the early Iron Age, already widely noted in other aspects of regional material culture. Finally, the material research on the ferrous remains is also significant for the understanding of the post-Iron Age phase of activities at Saruq al-Hadid, revealing evidence for metal scavenging and re-processing / recycling activities at the site during a period that is otherwise poorly represented in the material remains.</p>