The study presents a new approach for the investigation of ancient ferrous artefacts, by combining non-invasive and invasive techniques: neutron tomography, optical microscopy, and SEM-EDS, as applied to the objects from Saruq al-Hadid, U.A.E. It is revealed that despite the severe degradation of the objects, neutron tomography allows the detection of various features associated with the mechanisms of degradation and working (manufacturing, re-processing) of the ferrous artefacts including (1) different corrosion products and their specific distribution patterns; (2) surface dents from the use of hammers; and (3) various structural heterogeneities such as mineralised pierced holes, incised patterns, and ex-welding lines. The ex-welding lines present in every artefact have a major significance because they can be conveniently used for the investigation of the manufacturing techniques of the objects. The complementary invasive investigation via optical microscopy (OM) and SEM-EDS is used to relate the carburization patterns of the objects to their welding techniques, which are then associated with the patterns of variability of slag inclusion composition. The integrated data provide insight into the socio-technological aspects underlying the choices in the manufacturing of the Saruq al-Hadid objects, and broader aspects of early Iron Age iron-working in the ancient Near East.

Recent excavations at Saruq al-Hadid, Dubai, have recovered more than 200 kg of ferrous remains from early Iron Age contexts dated to c. 1250-800 BCE, transforming our understanding of the scale of early iron use in southeastern Arabia. Many of these ferrous artefacts show typological parallels with contemporary objects from Luristan in western Iran, and the possibility of their long-distance import from this well-known iron producing and using region has long been recognized. The present study uses material from Saruq al-Hadid and the contemporary site of Muweilah to explore the provenance of the earliest iron from southeastern Arabia, by (i) summarizing the evidence for the iron resources and technology in the region and adjacent areas; and (ii) compositionally analysing iron ores, iron slags and slag inclusions in artefacts from Saruq al-Hadid and Muweilah, alongside Iron Age ferrous artefacts from Iran, using OM, SEM-EDS, XRF, ICP-MS and LA-ICP-MS. Multivariate statistical analyses are used to explore these geochemical data, alongside a large dataset of ores and artefacts derived from existing geochemical and archaeological publications. The study identifies slag samples from Muweilah as originating from iron smithing activities, providing the first evidence for iron working of any kind in southeastern Arabia. Differences in the geochemical compositions of the material from Saruq al-Hadid and Muweilah and iron ores from the U.A.E. and Oman - particularly the distribution of rare earth elements - suggest that Iron Age ferrous artefacts from southeastern Arabia were not smelted from locally-available iron ores. Rather, the study demonstrates geochemical similarities between southeastern Arabian iron objects, contemporary objects from Luristan, and ores of the Sanandaj-Sirjan metallogenic belt of Iran, suggesting that iron may have been imported, at least partially as complete objects, from this region. Multiple source deposits are indicated, however, and the possible contribution of iron from other regions of ancient Western Asia and neighbouring regions remains to be further explored. The research provides critical new information regarding the long-distance exchange contacts of southeastern Arabia society during the floruit of the early Iron Age, in the late second and early first millennia BCE.

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.

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.

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.

This paper presents an integrated approach to the identification of complex re-processing operations of ancient ferrous artefacts from the multi-period site of Saruq al-Hadid, Dubai, United Arab Emirates. Spatial and morphological studies and a range of archaeometric analyses - optical microscopy, X-Ray diffraction, Micro-Raman spectroscopy, neutron tomography - are used to identify various processing markers preserved in these heavily corroded objects and to distinguish two groups of differently processed fragments. The main analytical focus is the investigation of corrosion layers preserving traces of hot oxidation and forging of metallic iron, along with re-heating of previously formed rust layers. The collected evidence suggests that the numerous iron artefacts ritually deposited of at the site in the early Iron Age were subsequently retrieved and re-forged into semi-products as a part of larger scheme of recycling operations, in which Saruq al-Hadid was a first node.