Cements are commonly used to engineer the environment around waste disposal sites. As groundwaters move through these sites, cement gradually dissolves and a reactive ‘hyperalkaline plume’ forms downstream. Published experimental and modelling studies of cement/rock reactions suggest that host-rock mineralogy will dissolve and be replaced initially by high-volume calcium silicate hydrate gels, and later by zeolites. Results of mineral/alkali experiments are presented. Examination of the reaction products, at the high analytical resolution afforded by ATEM, show new disordered phases which are structurally related to calcium silicate hydrates but are highly aluminous (relative to the published results of previous work). A review of archaeological analogue studies shows that old cement pastes easily become carbonated in the presence of CO 2 or carbonate waters. If protected from carbonation, however, cement gels can survive unchanged for thousands of years. New results of an ATEM examination of 1700 year-old Roman mortar from Hadrian’s Wall confirm that cement gels remain poorly ordered and reveal an aluminous CSH gel phase to be the chief product of mortar/dolerite reaction. These findings are discussed in the context of barrier engineering.

Establishing the provenance of mud, soil or other earth-derived particles found on items such as clothing, footwear or vehicles, can make a significant contribution to the intelligence and evidential phases of a forensic investigation. This paper reports the findings of a blind test case in which four experts in mineralogy, environmental particles, palynology and structural characterisation of organic matter at the molecular level were asked to provide information on the provenance of three soil samples from widely differing sites.The study demonstrated that combining multiple techniques and expert interpretations was very effective in the assessment of provenance for two out of the three study sites.At the other site, although the mineralogical analysis correctly identified the parent material to the level of the geological formation, some other lines of evidence proved to be potentially misleading. Clay mineralogy demonstrated a powerful potential to identify specific stratigraphic formations.Keywords: soil, palynology, mineralogy, particulates, lignin, TMAH, parent material 3The occurrence of earth-related particles such as minerals, pollen/spores and organic matter together with anthropogenic material on evidential items can help to establish their provenance, contributing to both intelligence and evidential stages of forensic investigations. For example, the search for the body of a murder victim in northern England during March 2005 was based on soil material believed to be from the body deposition site (1).The majority of soils across the UK (United Kingdom) landscape have developed over 10,000 years since the last ice age, with geochemical and mineralogical characteristics closely related to the parent material from which they formed (2). These parent materials include the underlying bedrock or any overlying Quaternary material such as glacial, riverine or windblown deposits. Individual parent material units vary in area from a few tens to hundreds of square kilometres. The proportions and characteristics of the dominant minerals (quartz, carbonates, clays) often differ sufficiently in the soils developed over these parent material types for them to be distinguished from one another at a regional scale. Hence, soil mineralogy could constrain potential source areas to a handful of regions based on expert interpretation and comparison with mineralogical databases and national maps showing the distributions of soils and parent material types.As the geology of the UK spans all the geological periods of the Earth's history with a diverse suite of parent rocks making up a relatively small landmass, it is likely to be wellsuited to the application of this approach. 4The provenance of a forensic sample might be further constrained if information is included on organic matter signatures of the lignin in plant fragments and pollen and spore assemblages. These two techniques are complementary as they provide information on vegetation types at and around the site, respectively. It may then be possible to ide...

Tel: +44(0)115 936 3038Fax: +44(0)115 936 3200 2 AbstractRadon exposure is a chronic and serious geohazard but with the correct knowledge of its distribution provided by an accurate radon potential map, this risk to human health can be reduced through well directed radon testing programmes and building control regulations.The radon potential map presented here, produced by mapping radon concentrations in homes, grouped by underlying geology, provides the most detailed and accurate assessment of radon in England.Bedrock and superficial geology associated with the most radon prone areas are investigated using the joint HPA-BGS radon potential dataset, geological information and, where available, soil geochemistry, airborne radiometric or laboratory analysis.Some of the geological units associated with high radon potential are well known, such as the granite intrusions in south west England, the Carboniferous limestones of Derbyshire and the Jurassic ironstones in Northamptonshire. This study provides a more comprehensive description of the main bedrock geological units associated with intermediate to high radon potential in England including: granites and associated uranium mineralisation in south west England; Devonian, Carboniferous, Permian and Jurassic limestones and dolomites; Devonian, Carboniferous, Jurassic and Cretaceous sandstones; Silurian, Devonian, Lower Carboniferous and Jurassic mudstones; Jurassic ironstones; and some Triassic breccias and conglomerates. Uranium in soil is elevated over many known radon-prone areas but also reflects the accumulation of U in organic-rich soil and peat. Near surface weathering, bedrock fracturing and former working of the ironstones in the English Midlands are all implicated in increased radon potential on these geological units.

Tree barks and attic dusts were examined as historical archives of smelter emissions, with the aim of elucidating the pathways of pollution associated with a plume of Sn and Pb contamination in top soils, found close to the former Capper Pass smelter, Humberside, UK. Samples were collected from three villages within the area of the contamination plume. Scanning Electron Microscopy (SEM) and bulk chemical analyses were used to assess particle type, number and deposition patterns. SEM analysis of dusts and bark revealed that Sn and Pb particles were present in samples from all three villages along with copper, zinc and iron particles. These were almost entirely <10 m in diameter and occurred mostly as oxides, frequently forming clusters of sub-micron crystals. Samples further from the smelter contained considerably fewer particles. We present images of smelter derived Sn particles. Chemical assays of the barks and attic dusts demonstrated that concentrations of Sn, Pb, Cu, As, Sb and Cd diminished with increasing distance from the source. Strong positive correlations were found between Sn and Pb, As, Sb and Cd in the attic dusts. Enrichment Factors (EF) were calculated for these trace elements based on topsoil element concentrations obtained from the soil survey of the study area.Decreases in these trace element concentrations and EF values with distance away from the smelter are consistent with trends found in the soil survey for Sn and Pb and are typical of deposition patterns around smelter stacks. The study demonstrates that tree bark and attic dusts can be effective archives of metal particulates deposited from large static emission sources.3

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