The collection of drainage samples from active stream channels for geochemical mapping is now a well-established procedure that has readily been adapted for environmental studies. This account details the sampling methods used by the British Geological Survey in order to establish a geochemical baseline for the land area of Great Britain. This involves the collection of stream sediments, waters and panned heavy mineral concentrates for inorganic chemical analysis. The methods have been adapted and used in many different environments around the world. Detailed sampling protocols are given, and sampling strategy, equipment and quality control are discussed.

This report presents the results of a geochemical survey carried out by the British Geological Survey (BGS) between 2001 and 2002. The survey collected 1381 urban soil samples at a density of 1 per 0.25 km2 and 241 rural samples at a density of 1 per 2 km2 on a systematic grid across the Glasgow conurbation. The study was carried out as part of the BGS Geochemical Baseline Survey of the Environment (G-BASE) project. Top (5 - 20 cm) and deeper (35 - 50 cm) soil samples underwent analysis for approximately 46 chemical elements including contaminants such as As, Al, Cd, Cu, Cr, Ni, Pb, Se, V and Zn according to standard G-BASE procedures. In addition, pH and loss on ignition (LOI) as an indicator of organic matter content were determined in the samples. The aim of the project was to provide an overview of the urban soil geochemistry of Glasgow and the immediate rural hinterland as an aid to planning and development. This report presents the initial findings of the Glasgow soil survey. The data have a wide range of applications and will be interpreted in more detail as part of a wider BGS Clyde Urban Super-Project (CUSP), to be reported elsewhere. This report documents the G-BASE soil survey and analytical methods and presents the distribution of soil parameters as a series of geographic information system (GIS)-generated graduated symbol geochemical maps. The Glasgow conurbation is the largest built-up area in Scotland and has a long history of urban and heavy industrial development including coal and other mineral mining; ship building; steel and iron making; railway engineering; car manufacture and - until the 1960s - was home to the world’s largest chromium ore processing plant based in Rutherglen in the south-east of the city. As with all cities, urban land quality in Glasgow is the result of complex interactions between these man-made inputs and the natural concentrations of substances in soil, which are influenced by the geology and soil forming processes. Therefore, comparisons with rural soils can help elucidate the level of anthropogenic input to soils in urban areas. As an indication of anthropogenic (man-made) pollution, the results of the present study reveal that on the basis of median values, Cd, Cr, Ni and Zn concentrations are 2-3 times and Cu and Pb 5-7 times higher in Glasgow than the national average in Scottish soils. However, these results should be treated with caution due to the difference in analytical methods between the current G-BASE project and the national data for Scotland. Nevertheless, Ag (x 3.5), As, Co, Ge, Mo and P2O5 (~ x2) are also enhanced in Glasgow urban soils relative to world averages. Similarly, Pb (x 7.5), Cu, Ni, Sb, Sn and Zn (~ x2) and Se (x3) are enriched in Glasgow urban soils relative to world averages and are higher than BGS regional geochemical median values for the Humber-Trent area of England. This may in part reflect anthropogenic pollution and in the case of As, Co, Mo, Ni, and Se the presence of coals and volcanic bedrock in the Glasgow area. Comparisons between median values in the Glasgow dataset and other urban areas surveyed by the G-BASE project in the UK show that Cr and Ni are higher in Glasgow soils than most other cities. This is attributed to the history of Cr-processing and heavy industry in Glasgow and the presence of coals underlying the city and volcanic bedrock on the outskirts of Glasgow. In contrast, As, Cd and Pb are lower in Glasgow soils than most other urban areas. The results of the present study demonstrate that regardless of parent material type, concentrations of As, Bi, Ba, CaO, Ce, Co, Cr, Cu, Ge, Mo, Ni, Pb, Sb, Se, Sn, Sr, Th, Y, Zn and pH are generally higher in urban than rural soils in the Glasgow area. Elements that are rare in nature in most environments but commonly associated with anthropogenic pollution such as Pb, Sb and Sn show greatest levels of enrichment (2.6 – 3.3 times, based on median values) in the urban soils. Calcium is also enhanced significantly (x2.1, based on median values) in deeper urban than rural soils probably as a result of buildings, coal and industrial waste in the urban environment, which tend to be calcareous in nature and commonly used as fill materials. Indeed, high Ba, CaO, Sr and pH soils are closely associated with made ground, industrial and derelict land in the city probably reflecting the presence of fill materials. The elements that show greatest enhancement in the Glasgow urban environment, namely CaO, Cu, Mo, Ni, Pb, Sb, Sn and Zn are a typical indicator ‘suite’ of urban anthropogenic pollution commonly identified in studies of urban areas under the G-BASE project. Conversely, levels of organic matter are lower in urban than rural soils and several elements that are closely associated with organic matter show the same relationship including Br, I, U and W. Concentrations of Hf, SiO2, TiO2 and Zr are also lower in urban than rural soils as these elements are more closely associated with the detrital mineral composition of natural soils. Despite the over-riding influence of urban anthropogenic pollution on the soil geochemistry of many elements, geology and geogenic processes still exert a fundamental control on soil composition. Results in rural and urban Glasgow soils demonstrate that, for example, many elements such as Al2O3, Co, Cr, Cu, Ga, Ni, Pb, Se, Sn, Th, TiO2, U, V and Zn are relatively lower in concentration over Devonian sandstones present in the Dumbarton area as a result of natural geological processes including the lower clay content of these rock types. Similarly, many elements associated with alkali basaltic lavas (for example, CaO, Fe2O3, MgO, Na2O, Nb, Ni, P2O5, Sr, TiO2 and V) are relatively higher in soils over the Clyde Plateau Volcanic Formation, to the north and south of the city than other rock types in the area. Superficial peat deposits also have an effect on the geochemistry of the soils due to the importance of organic matter on the distribution of many elements such as As, Br, Cd, Co, Cs, Ga, Ge, I, Mo, Pb, Sb, Se, Sn and U in the environment. As might be anticipated, pH is also lower in these soils due to the presence of humic acids.

Until recently systematic data on the chemical quality of urban soils was lacking in many countries as traditional soil survey programmes focussed on rural environments and avoided urban areas. The advent of environmental protection legislation in the UK in the 1990s and drivers to reutilise brownfield sites for development prompted a need for urban soil quality information to aid sustainable planning and urban regeneration and create healty environments. Since 1992, the British Geological Survey (BGS) has completed urban soil surveys in 27 United Kingdom (UK) cities as part of the national Geochemical Baseline Survey of the Environment (G-BASE) Project[1,2,3]. This includes a survey of the Glasgow urban and surrounding rural areas to link to a wider geoenvironmental assessment that the BGS is carrying out in the region - the Clyde and Glasgow Urban Super Project (CUSP)[4]. Glasgow is Scotland’s largest city and was a major centre of heavy engineering and industrialisation until the mid 20th century. Much of this industry has now declined leaving tracts of derelict/brownfield land, which are gradually being regenerated. The G-BASE survey provides an overview of land quality in Glasgow and the results have a variety of applications to environmental quality assessments including greater understanding of the impacts of anthropogenic pollution and potential threats to ecoystems and human health.

The OPAL project is a partnership initiative designed to encourage the public to become more involved with the natural world. The partnership is funded by the Big Lottery Fund, led by Imperial College London, and is conducted throughout England. The project aims to involve the public in scientific research, resulting in a large volume of data to develop a greater understanding of the England’s natural environment. In addition it aims to: encourage participation in outdoor activities; develop educational programmes for people of all ages and abilities; enthuse a new generation of environmentalists; and develop partnerships between the community, voluntary and statutory sectors. OPAL is delivered through nine regional programmes, five thematic Centres, and a Support system. University College London (UCL) leads the OPAL Water Centre, one of the thematic centres, which aims to investigate the condition of lakes and ponds in England with respect to pollution impacts. The research aims to identify the scale of contamination from trace metals and persistent organic pollutants, and the extent to which this pollution affects the freshwater ecosystem (Davies et al., 2011).

The British Geological Survey’s Geochemical Baseline Survey of the Environment (G-BASE) project is responsible for the systematic geochemical mapping of the land surface of Great Britain. Samples of soils, stream sediments and stream waters collected at an average density of 1 sample per 1.5 km2 are determined for up to 46 elements/parameters.

Systematic baseline sampling of soils in urban and rural areas has been undertaken by the British Geological Survey’s (BGS) Geochemical Baseline Survey of the Environment (G-BASE). Using these urban and rural data in conjunction with each other provides a more powerful, and useful, interpretation of urban soil quality data to be made.

Research in the top few metres of the ground beneath our feet has traditionally been split between soil science, geology and several sub-disciplines. This has lead to different working practices, classifications and boundaries as well as inconsistent approaches to databasing and modelling. A significant uncertainty lies within the “transition zone” between the pedosphere and geosphere. The British Geological Survey (BGS) set out to investigate this zone through multidisciplinary field surveys at both a site specific and catchment scale in representative soil-geoscapes across the UK. The spatial 3D soil-geology model is developed by the combination of spatial soil and geoscientific findings. Whilst undertaking these studies the BGS were particularly interested in investigating whether technologies developed to map geology in 3D can be used to routinely develop spatial models of the soil-geology environment, and if technologies used in digital soil mapping can assist in reducing uncertainties associated with such models at a variety of scales. The presented soil-geology model is an example of recent work carried out on an area of approximately 2 km2 near Shelford, Nottinghamshire, UK. The site lies on the River Trent floodplain and an adjacent gentle slope of Triassic mudstone. The whole site is underlain by typical red mudstones of the Triassic Mercia Mudstone Group with some interbedded greenish grey siltstones and sandstones. This is overlain by up to 5 m of Pleistocene and Holocene river terrace deposits, varying from sand to coarse gravels and Holocene alluvial and colluvial deposits. Fieldwork was orientated along several parallel traverses running from the hilltop, downslope towards the River Trent. The study of the survey area comprised of two main stages. Firstly a field survey which included techniques such as a detailed soil and geological survey, pitting and drilling, installation of piezometres, soil moisture tests, high-resolution electrical mapping, electrical resistivity tomography, ground penetrating radar, magnetic susceptibility, gamma spectrometry, remote sensing and terrain analysis. The second stage involved the digital assembly of data, processing, and the development of the 3D soil-geology model. Each survey delivered its own results in form of maps, tables and property models which were collated into one software package (GSI3D by INSIGHT GmbH). Developing a solid 3D soil-geology model in GSI3D utilizes a Digital Terrain Model, mapped geological and soil line work, downhole borehole and augerhole data, and geophysical data. This enables the geoscientist to construct regularly spaced intersecting cross-sections by correlating boreholes and the outcrops-subcrops of units to produce a fence diagram of the area. Mathematical interpolation between the nodes along the sections and the limits of the units or horizons produces a solid model comprising of a series of stacked triangulated volume objects. The final 3D model shows several top- and subsoil horizons in conjunction with the underlying Holocene, Pleistocene and red Triassic Mercia Mudstone parent materials. These models can aid studies of near surface processes including the movement of water, dissolved agricultural nutrients and associated eroded soil particles.