Archaeological wrought iron artefacts are subject to damaging corrosion while in the burial environment and when subjected to environmental changes after excavation. The role of water, oxygen, and chloride corrosion accelerators are central to iron corrosion processes. Intrinsic factors such as the amount and distribution of slag in wrought iron may also play a role in corrosion processes. This study examined a range of factors that impact on understanding conservation desalination treatments to mitigate corrosion by removing chlorides. While examining the effect of slag on corrosion rate and chloride content formed the core of this project, cracking morphologies within corrosion product layers and their influence on corrosion rates measured by oxygen consumption produced outcomes of interest for designing the practicalities of treatment procedures. The slag content of the wrought iron objects examined in this study did not correlate with either their corrosion rate or their chloride content. In line with other authors, clustering of chloride around slag inclusions was identified. This confirmed slag does act as a focus for developing corrosion centres, which will offer challenges for chloride removal and hence provide opportunity for post-treatment corrosion. The alkaline sulphite washing applied to the iron nails produced results that aligned with those reported in other studies and confirmed its relative efficiency for removing chloride. Of major relevance to conservators designing alkaline washing techniques is assigning treatment time and specifying treatment environment. These decisions are aided by evidence provided in this study, which showed that immersing the chloride ii containing corrosion product β-FeOOH in alkaline sulphite entirely transformed it to other iron oxides in only 30 days. During this process it will release its chloride, which will be available for diffusion into the wash solution making a more complete desalination process possible.

Without the protection provided by anti-corrosive paints, vehicles, bridges and industrial heritage would not have survived for long. Where these coatings fail or are damaged, ferrous metal requires further protection. To provide insight into coating failure a survey of paint layers and corrosion products found on historic wrought iron and mild steel was carried out around Scotland. Corrosion has also been found to be a major contributor to structural damage of historic armoured vehicles. When choosing coatings within conservation, decisions are based on qualitative data and practitioners’ experience rather than evidence based standards for specific ferrous alloys in particular environmental conditions. Limited quantitative data exists hence this research seeks to produce quantified data via a standardised approach. To provide environmental context for the laboratory based tests, temperature and humidity data from the Tank Museum has been considered. Thus the anti-corrosive performances of clear coatings on historic armoured steel have been assessed in controlled temperature and relative humidity by using a sensitive corrosion monitoring technique. For relevance to the conservation sector common materials, methodology and environmental conditions were considered and standardised. Aluminium oxide blasting of the steel removed contaminants and provided a keyed surface for Paraloid B72 and Cosmoloid H80, popular clear coatings within conservation and Siliglide 10, a modern silane based coating. All three coatings offered protection for the steel whether applied to cleaned surfaces or to pre-corroded surfaces. The best treatment method and thus the treatment recommended for protecting areas of paint-loss is to clean the surface and apply three layers of Paraloid B72. The standardised approach used allows other researchers to contribute comparable data to the production of a database and future standards within conservation.

This thesis examines the inhabitation of the lower Exe valley, between the Mesolithic and the Early Bronze Age through the evidence of a series of surface lithic scatters. Research draws on recent confident approaches to surface lithic scatters which view them as key data for understanding the inhabitation of prehistoric landscapes. Theoretically it draws on the dwelling perspective and proposes that both the contents of lithic scatters (the stone tools and debitage of which they are composed), and their contexts (the locations in which they are found) are inseparable parts of the same whole, and are implicated in the processes through which prehistoric populations came to understood and create their worlds. Research focuses on a small study area centred on the lower Exe valley, Devon. It is one of the most significant prehistoric landscapes in lowland southwest Britain and includes a large surface lithic collection spanning the Mesolithic to the Early Bronze Age. It also contains evidence for a number of contemporary monuments. Several methodologies are applied to the contents and contexts of the study area’s lithic assemblages. Methodologies utilised include lithic analysis, landscape phenomenology, LIDAR and vertical aerial photography, extensive geophysical survey and targeted excavation. Four themes are explored in relation to the study area’s archaeological record: • The character and composition of inhabitation • The temporality of inhabitation • Biographies of place • Scales of mobility and contact Results indicate the valley floor and its immediate western edge as a particular focus of activity during all periods. Against the background of increasing intensity and extent of inhabitation between the Mesolithic and Early Bronze Age, the repeated occupation of persistent places is noted. Repeated occupation of these locales is seen as key to the development of biographies of place which in turn act as anchors for subsequent acts of inhabitation and monument building. This thesis combines the analysis and interpretation of previously unpublished surface lithic assemblages, with the results of new archaeological fieldwork. At a regional level it has enhanced understanding of the prehistory of lowland Devon. In a wider context it offers a new theoretical and methodological approach to studying surface lithic scatters, and contributes to on going debates in landscape archaeology.

The research presented aimed to investigate potential of subcritical fluid technology to effect Cl- release and transform compounds of copper alloy artefacts of cultural significance. The work intended to determine the most effective pH, temperature, and time combination subcritical treatment variables to: 1. transform or solvate insoluble or sparingly soluble copper compounds containing Cl - CuCl and Cu2(OH)3Cl (atacamite and clinoatacamite); 2. examine impact on typical patina compounds Cu2O and ‎Cu2CO3(OH)2 and to establish optimal conditions for their retention throughout treatment. Additionally, the research expected to offer guidance on the values of the operational parameters to use when applying subcritical treatment to archaeological copper alloy objects. The series of experiments yielded preliminary results on solvation, extraction, chemical transformation, and physical modification of the predominant corrosion products found on copper alloy artefacts. Experiments were completed using analogue pressed pellets of corrosion products, naturally corroded copper coupons and archaeological artefacts, with specific focus on corrosion profiles, metallography and microstructure. The results of extraction show significant amounts of Cl- are removed and thus the reactivity of objects is reduced. While this study conclusively demonstrated subcritical treatment is capable of both removal and transformation of Cl-bearing compounds commonly present in copper alloy objects, it cannot be recommended for treating archaeological objects based on these results alone. Aesthetic and physical changes are unpredictable and may be unacceptable. Accepting these changes cannot directly be balanced against the proven effectiveness of subcritical treatment for removing Cl, nor its rapid treatment time.