GEMAS: Source, distribution patterns and geochemical behaviour of Ge in agricultural and grazing land soils at European continental scale

Accepted Manuscript GEMAS: Source, distribution patterns and geochemical behaviour of Ge in agricultural and grazing land soils at European continental scale Philippe Negrel, Anna Ladenberger, Clemens Reimann, Manfred Birke, Martiya Sadeghi PII:

S0883-2927(16)30124-X

DOI:

10.1016/j.apgeochem.2016.07.004

Reference:

AG 3682

To appear in:

Applied Geochemistry

Received Date: 25 May 2016 Revised Date:

8 July 2016

Accepted Date: 8 July 2016

Please cite this article as: Negrel, P., Ladenberger, A., Reimann, C., Birke, M., Sadeghi, M., the GEMAS Project Team, GEMAS: Source, distribution patterns and geochemical behaviour of Ge in agricultural and grazing land soils at European continental scale, Applied Geochemistry (2016), doi: 10.1016/ j.apgeochem.2016.07.004. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

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GEMAS: SOURCE, DISTRIBUTION PATTERNS AND GEOCHEMICAL BEHAVIOR OF Ge IN AGRICULTURAL AND GRAZING LAND SOILS AT EUROPEAN CONTINENTAL SCALE

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Philippe NEGREL1, Anna LADENBERGER2, Clemens REIMANN3, Manfred BIRKE4,

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Martiya SADEGHI2, and the GEMAS Project Team5.

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BRGM, Laboratories Division, Orléans, France, [email protected]

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Geological Survey of Sweden, Uppsala, Sweden, [email protected],

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[email protected]

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Geological Survey of Norway, Trondheim, Norway, [email protected]

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Bundesanstalt für Geowissenschaften und Rohstoffe, Stillweg 2, 30655 Hannover,

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Germany, [email protected]

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The GEMAS Project Team: S. Albanese, M. Andersson, R. Baritz, M.J. Batista, A. Bel-lan, D. Cicchella, A. Demetriades, B. De Vivo,W. De Vos, E. Dinelli, M. Ďuriš, A. Dusza-Dobek, O.A. Eggen, M. Eklund, V. Ernstsen, P. Filzmoser, D.M.A. Flight, S. Forrester, M. Fuchs, U. Fügedi, A. Gilucis, M. Gosar, V. Gregorauskiene, W. De Groot, A. Gulan, J. Halamić, E. Haslinger, P. Hayoz, R. Hoffmann, J. Hoogewerff, H. Hrvatovic, S. Husnjak, L. Janik, G. Jordan, M. Kaminari, J. Kirby, J. Kivisilla, V. Klos, F. Krone, P. Kwećko, L. Kuti, A. Lima, J. Locutura, D. P. Lucivjansky, A. Mann, D. Mackovych, M. McLaughlin, B.I. Malyuk, R. Maquil, R.G. Meuli, G. Mol, P. O’Connor, R. K. Oorts, R.T. Ottesen, A. Pasieczna, W. Petersell, S. Pfleiderer, M. Poňavič, S. Pramuka, C. Prazeres, U. Rauch, S. Radusinović, I. Salpeteur, R. Scanlon, A. Schedl, A.J. Scheib, I. Schoeters, P. Šefčik, E Sellersjö, F. Skopljak, I. Slaninka, A. Šorša, R. Srvkota, T. Stafilov, T. Tarvainen, V. Trendavilov, P. Valera, V. Verougstraete, D. Vidojević, A. Zissimos and Z. Zomeni.

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Abstract Agricultural soil (Ap-horizon, 0–20 cm) and grazing land soil (Gr-horizon, 0–10 cm) samples

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were collected from a large part of Europe (33 countries, 5.6 million km2) as part of the

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GEMAS (GEochemical Mapping of Agricultural and grazing land Soil) soil mapping project.

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GEMAS soil data have been used to provide a general view of element mobility and source

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rocks at the continental scale, either by reference to average crustal abundances or to

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normalized patterns of element mobility during weathering processes. The survey area

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includes a diverse group of soil parent materials with varying geological history, a wide range

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of climate zones, and landscapes.

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The concentrations of Ge in European soil were determined by ICP-MS after an aqua

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extraction, and their spatial distribution patterns generated by means of a GIS software.

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The median values of Ge and its spatial distribution in Ap and Gr soils are almost the same

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(0.037 vs. 0.034 mg/kg, respectively). The majority of Ge anomalies is related to the type of

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soil parent material, namely lithology of the bedrock and minor influence of soil parameters

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such as pH, TOC and clay content. Metallogenic belts with sulphide mineralisation provide

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the primary source of Ge in soil in several regions in Europe, e.g. in Scandinavia, Germany,

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France, Spain and Balkan countries.

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Comparison with total Ge concentrations obtained from the Baltic Soil Survey shows that

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aqua regia is a very selective method with rather low-efficiency and cannot provide a

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complete explanation for Ge geochemical behaviour in soil. Additionally, large differences in

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Ge distribution are to be expected when different soil depth horizons are analysed.

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Keywords: germanium, agricultural soil, weathering, geochemistry

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1 – Introduction

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Germanium-silicon is a geochemically-related pair of elements which follow each other either

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during crustal evolution (De Argollo and Schilling, 1978) or during weathering (Kurtz et al.,

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2002). The coherence of the behaviour between Ge and Si is due to the similarity in ionic

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radius, valence and ionization potential (Goldschmidt, 1954; Rosenberg, 2009). Silicon is one

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of the tracers of silicate weathering of felsic (granite) and mafic lithologies (basalt) (Kurtz et

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al., 2002; Lugolobi et al., 2010), therefore Ge has been used as possible analogue of the major

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element Si in these studies.

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More specifically, Ge is a trace element in the Earth’s crust, with an abundance of 1.35

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mg/kg in the upper continental crust (Rudnick and Gao, 2003; Hu and Gao, 2008). Due to its

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opportunistic siderophile, lithophile, chalcophile and organophile character there are no large

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differences in the Ge concentration in most common rock types and the values quoted by El

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Wadarni (1957) and Hu and Gao (2008) are respectively 1.1 mg/kg for granite and 1.5 mg/kg

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for shale . Some of the highest Ge contents (up to 2 mg/kg) have been reported by Melcher

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and Buchholz (2014) for deep-sea pelagic clay sediments. Because of nearly identical ionic

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radii and electron configurations of Ge and Si, the crustal geochemistry of Ge is dominated by

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a tendency to replace Si in the lattice sites of minerals (Goldschmidt, 1954; De Argollo and

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Schilling, 1978; Rosenberg, 2009). Another typical occurrence of Ge is in sulphide form. Few

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germanium minerals, including germinates, are known in nature. Ge is present as minor

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element in Cu, Zn and Pb sulphide minerals (up to 3000 mg/kg in sphalerite; Melcher et al.,

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2006; Höll et al., 2007; Melcher and Buchholz, 2014), in rock-forming silicate minerals, such

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as olivine, pyroxene, amphibole, feldspar and muscovite, and in accessory minerals such as

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garnet, topaz, hematite and cassiterite. High Ge contents have also been noted from secondary

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deposits rich in goethite (> 5000 mg/kg; Bernstein, 1985). Coal and lignite can occasionally

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be enriched in Ge. Under hydrothermal conditions, Ge is chalcophile and preferentially

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weathering environment and during soil formation Ge is sorbed by clay minerals, co-

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precipitates with Fe-oxides and has a strong tendency to bind to organic matter (Kurtz et al.,

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2002; Scribner et al., 2006; Rosenberg, 2009; Lugolobi et al., 2010). Germanium compounds

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dissolved in water (especially enriched in thermal springs) can be toxic. Typical

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anthropogenic sources of Ge in the environment are emissions from metal smelters and coal-

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fired power plants (fly ash may contain up to 15 mg/kg Ge; Melcher and Buchholz, 2014). Up

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to early 2000 several European countries (Austria, Germany, Belgium) were producing

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primary Ge from processing of sulphide ores, mainly Zn oresbut their production ceased and

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the Ge market is now dominated by Chinese (70 %), Russian (4%) and American (2%)

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companies (Jorgenson, 2002). In Europe, Finland remains a minor producer (Melcher and

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Buchholz, 2014). Germanium from recycling and zinc refining is still produced in Belgium

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(Olen), and Germany (Langelsheim and Osterwieck) (Melcher and Buchholz, 2014).

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Germanium is widely used in the electronics industry and has recently been classified as

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“critical metal” (Melcher and Buchholz, 2014). Germanium is a semiconductor and was early

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on used in transistors, usually doped with arsenic, gallium, antimony or indium, in thousands

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of electronic applications (Haller, 2006; Rosenberg, 2009). Nowadays, it is replaced by other

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types of semiconductors. Other applications include (Rosenberg, 2009): wide-angle camera

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lenses, objective lenses for microscopes, fiber optics, fluorescent lamps, rewritable DVDs

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(due to Ge index of refraction and dispersion) and as a catalyst. Germanium (pure and in

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oxide form) is transparent to infrared radiation and commonly used in infrared detectors, night

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vision systems, thermal imaging cameras and spectroscopes (Guberman, 2015). Germanium

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doped with phosphorus has been used in fluorescent lamps and in LEDs. Some germanium

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compounds have been recently tested in chemotherapy and some other medical treatments due

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to their possible antibacterial properties (Goodman, 1988; Angerer et al., 2009; Rosenberg,

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2009). Around 30% of the total Ge used in production comes from recycling, e.g. as scrap

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from optical devices and from decommissioned military vehicles (Guberman, 2015). Taking into account the growing market and applications of Ge, its geochemical

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behaviour and spatial distribution in various natural materials (rocks, soil, water) in Europe is

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of high importance for the assessments of the mineral resource potential and for

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environmental purposes. Unfortunately, reliable Ge data are still rare in the literature, mainly

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due to the low abundance of Ge, often below the detection levels for most analytical methods

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(El Wadarni, 1957; Burton et al., 1959; Bernstein, 1985; Rudnick and Gao, 2003).

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The main aim of this paper is to illustrate the distribution of Ge in European

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agricultural (Ap) and grazing (Gr) land soils, using the GEMAS database (GEMAS

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Geochemical mapping of agricultural and grazing land soils of Europe). The agricultural soil

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GEMAS dataset (Reimann and Caritat, 2012, Reimann et al. 2014a, b) is an excellent base for

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studying large scale variations related to factors like lithology, climate, topography, soil

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texture and anthropogenic impact on soils (e.g. Albanese et al., 2015; Ladenberger et al.,

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2015; Négrel et al., 2015; Ottesen et al., 2013; Reimann et al., 2012a, b; Sadeghi et al., 2013;

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Saaltink et al., 2013; Scheib et al., 2012; Tarvainen et al., 2013). Here, Ge mobility and its

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source(s) in an aqua regia extraction at the continental scale is provided. The observed Ge

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anomalies at the European scale are attributed to either natural factors such as geology,

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weathering and mineralisation or to possible anthropogenic sources, e.g. metal processing and

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coal fired power plants.

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2 - General setting

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The GEMAS project (Geochemical mapping of agricultural and grazing land soils of Europe,

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Reimann et al., 2014a, b) was carried out by the Geochemistry Expert Group of

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EuroGeoSurveys in cooperation with Eurometaux (European Association of Metals) and

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managed by the Geological Survey of Norway, NGU (Reimann and Caritat, 2012). Soil

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(Reimann et al., 2012a; 2014a, b). The survey area is shown in Figure 1. The main objective

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of the project was to detect and to map the natural element variation (the background) at the

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European scale, the soil samples were never taken at known contaminated sites, in the

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immediate vicinity of industry or power plants, a railway line or a major road, directly below

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high power electric lines or near to pylons. The GEMAS results and their interpretation are

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provided in a two-volume geochemical atlas (Reimann et al. 2014a, b) where the aqua regia

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and XRF results (and other soil parameters such pH, TOC, CEC etc.) are discussed in detail in

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respect to their spatial distribution on geochemical maps. The complete dataset on DVD is

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available with the atlas. The geochemical atlas has been followed by a series of peer-reviewed

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publications where a considerably more detailed interpretation of the regional distribution of

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single elements or related groups of elements was presented, e.g. Reimann et al. (2012b - Pb),

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Ottesen et al. (2013 - Hg), Tarvainen et al. (2013 - As), Scheib (2012 - Nb) ; Sadeghi et al.

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(2013 - Ce, La, Y); Ladenberger et al. (2015 – In) ; Albanese et al., (2105 – Cr, Ni, Co, Cu).

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3 – Material and methods

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Two types of soil, grazing land soil and agricultural soil have been collected at a sampling

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density of 1 site each per 2500 km2 (Fig. 1b). Grazing land soil (Gr) has been defined as land

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under permanent grass cover and samples were taken from a depth of 0–10 cm. Agricultural

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soil samples (Ap) were collected from regularly ploughed fields at a depth of 0–20 cm,

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according to REACH (Registration, Evaluation and Authorisation of Chemicals - EC, 2006)

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specifications. Each sample (ca 3.5 kg) corresponds to a composite of five sub-samples taken

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from the corners and centre of a 10 × 10 m square. The total number of Ap samples is 2108

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and that of Gr samples 2024. A single facility (State Geological Institute of Dionyz Stur,

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Slovakia) prepared all samples for the analyses: soils were air-dried, sieved to <2 mm using a

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nylon screen, homogenised and finally split into 10 sub-samples. Two project reference

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during the project. At the end of the project the two reference samples underwent an

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international ring test to establish the reference values (Kriete, 2011; Reimann and Kriete,

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2014). Samples were analysed using bulk composition and partial extraction methods

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(Reimann et al., 2012a; 2014a, b).

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An aqua regia digestion was applied to the soil samples prior to analysis with ICP MS

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and ICP AES. Around 15 g of the <2 mm fraction was leached in 90 ml of aqua regia (95°C, 1

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hour) and then made up to a final volume of 300 ml with 5% HCl. The solutions were

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analysed using ICP-AES and ICP-MS at ACME laboratories in Vancouver, Canada. A total

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of 53 elements was determined on around 5000 soil samples using matrix matched standards

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and reference materials.

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A rigorous quality control (QC) procedure was part of the analytical protocol

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(Reimann et al., 2012a). Samples were analysed in batches composed of 20 samples. In each

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batch, one field duplicate, one analytical replicate of the field duplicate and the project

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standard were inserted. The practical detection limit (LD) was estimated from results of the

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GEMAS project replicate samples through the estimation of regression line coefficients by the

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‘reduced major axis line’ procedure (Reimann et al. 2014a, b). This LD for Ge analyzed in the

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aqua regia extraction by ICP-MS is 0.02 mg/kg. Details on analytical procedures and quality

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control are provided in a technical report and in the GEMAS atlas (Reimann et al., 2011;

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2014a).

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Comparable to GEMAS, during the Baltic Soil Survey (BSS), agricultural soils were

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collected in the survey area encompassing the catchment basin of the Baltic Sea and Norway

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(Reimann et al., 2000). The sampling density was, as in the GEMAS project, 1 site/2500 km2,

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but for the BSS two samples were taken at each site: topsoil 0–25 cm (ploughing layer, Ap-

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horizon) and subsoil (bottom samples, usually B- or C-horizon) at an approximate depth of

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composite of 5–13 subsamples was collected from an area measuring 100 m ×100 m. The

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Geological Survey of Norway (NGU) carried out the sample preparation and the samples

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were analysed at the Federal Institute for Geosciences and Natural Resources (BGR,

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Hannover, Germany) and the Geological Survey of Finland (GTK) using a variety of

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extractions and instrumental methods (see Reimann et al., 2000 for details). Germanium was

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analysed using a near total extraction (4 acid, including HF, DL: 0.1 mg/kg) followed by an

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ICP MS analysis allowing comparison of total to partial Ge concentrations in agricultural soil

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of northern Europe.

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Due to the fact that geochemical data are compositional data, element concentrations

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reported in wt % or mg/kg sum up to a constant and are thus not free to vary. The information

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value of such data generally lies in the ratios between the variables (Reimann et al., 2012a).

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Compositional data do not plot in the Euclidian space, but rather on the Aitchison simplex

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(Aitchison, 1986). Thus, only order statistics are used to present the data but note that the

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percentiles used for map production remain unchanged under log-transformation only but not

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under a log-ratio-transformation. Because the Ge concentrations for many samples are under

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the detection limit, we choose to present the GEMAS data in a form of black and white point

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source maps. The point source maps display the analytical result for each single sample on a

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map, and are a very objective presentation of the spatial aspects of the data. Instead of using

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the 'growing dot map' where a dot grows proportionally to the analytical result, Exploratory

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Data Analysis (EDA) symbol maps using classes and symbols to display the percentages of

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the data set (0, 5, 25, 75, 95, 100) were chosen in order to better reflect the spatial data

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structure on the resulting map.

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The colour surface maps for the Baltic soil survey were produced using kriging, based

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on a careful variogram analysis. The kriging was used to convert the values from the

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ACCEPTED MANUSCRIPT irregularly distributed sampling sites to a regular grid. Class boundaries used for the colour

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maps are based on percentiles, similarly as for GEMAS point source maps. Black and white

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point source maps are additionally provided in the BSS atlas (Reimann et al., 2003).

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4 – Results and Discussion

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4.1. Aqua regia extractable Ge concentrations in GEMAS agricultural and grazing land soils

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It is commonly known that strong acid digestion methods have a variable efficiency in

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dissolving minerogenic samples, depending on their composition, acid mixture used, timing,

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temperature and other factors. The best method to validate the extractability of the acid-based

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extraction is to calculate the extractability when total concentrations results are available.

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In addition to former investigation of the digestion by hot aqua regia (Davidson et al.,

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1994; Madrid et al., 2007), it has been argued that aqua regia acid mixture hardly attacks

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some silicate phases (e.g. barite, zircon, monazite, sphene, garnet, ilmenite, rutile…) while

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other silicates and oxides are weakly to moderately dissolved (Vilà and Martínez-Lladó,

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2015). For the determination of Ge in the GEMAS soil samples an aqua regia digestion was

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used according to REACH requirements (EC, 2006). The resulting Ge median is almost

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identical in the two sample materials collected: 0.037 mg/kg in the Ap and 0.034 mg/kg in the

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Gr samples. The concentration levels are low, mainly due to rather poor solubility of

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elemental germanium in hydrochloric acid (Rosenberg, 2009). This has been further examined

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in Figure 2 together with the histograms, the density traces and a one-dimensional

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scattergrams. The boxplots show the similarity between the Ge results in the Ap and Gr soil

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samples and the overlap of Ap and Gr median values. The Wilcoxon rank sum test (p-value of

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0.029) confirming that the two medians are equivalent at the 5% significance level. The

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truncation of the boxplots at their lower end is caused by the large number of samples below

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the detection limit (visible also in the histogram and in the density trace and one-dimensional

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scattergram). The combined diagram with the boxplot, the histogram and the density trace one

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dimensional scattergram (Fig. 2) shows that the Ge univariate data distribution in an aqua

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regia extraction is approximately symmetrical in the log-scale. Although the boxplots do not

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identify any outliers, the one-dimensional scattergram highlights the existence of some

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samples with unusually high Ge values (> 0.1 mg/kg).

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The cumulative probability diagram of aqua regia extractable Ge (Fig. 3) represents

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one of the most powerful tools to study the data distribution (Reimann et al., 2012a), as it

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detects breaks in the data structure which may indicate subpopulations or certain geochemical

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processes. The differences between the distribution and variation of the Ap and Gr soil

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samples appear to be minimal for almost the whole range. Such uniform statistical

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distributions of the Ap and Gr data sets have otherwise only been observed for the major

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elements (Reimann et al., 2012a). Slightly higher maximum values are observed for Gr

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samples and this difference is noted for a small amount of population above the 99th

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percentile. On the other hand, almost 30 % (541 samples) of the results lie under the detection

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limit (Fig. 3). The Ge concentrations from the aqua regia extraction in soils from the

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European countries participating in the project are compared using boxplots in Figure 4.

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Substantial differences in the regional distribution of Ge become visible in this plot with the

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highest median in both the Ap (red) and Gr (green) soil samples observed in Montenegro

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(0.077 mg/kg), followed by Slovenia and Finland (Fig. 4). In general, the countries with

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higher Ge median can be divided into three groups, the first one represented by Balkan

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countries, the second one by the Mediterranean region with Greece, Italy and Cyprus and the

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third group with Finland and Norway. Additionally, the Nordic countries (Finland, Norway

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and Sweden), Italy and Czech Republic tend to show some extreme Ge concentrations in soil.

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followed by Denmark and the three Baltic States and The Netherlands. A notable feature of

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many of the country boxplots is their truncation at the lower end, due to many Ge values

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being below the detection limit. The detailed explanation of country anomalies can be found

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in Table 1 and in the following section 4.3.

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4.2 Germanium variation in GEMAS soils compared to the bedrock lithology

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When comparing the maps of most elements investigated in the GEMAS project, the majority

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of anomalies is related to bedrock lithology. A variety of quite different geological maps of

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Europe (e.g., Dürr et al., 2005; Hartwich et al., 2005; Günther et al., 2013) are available and

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comparing the element concentrations in soil developed on the top of geological units with

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different lithology and specific composition is a crucial step in defining the soil parent

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material. The geological map of Europe (Fig. 1a) suggests a geological separation between

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the Nordic countries (Caledonian Mountain Chain + Baltic Shield) with a predominance of

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glacial and postglacial deposits developed on old crystalline bedrock versus the rest of Europe

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with the large sedimentary basins and, in general, much more varied lithologies and younger

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rocks. The examples mentioned above demonstrate that it is quite difficult to derive a

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generalized geological map of Europe. Often, too many units are defined on geological maps

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precluding the possibility to obtain reasonable subgroups of samples that are large enough for

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a statistically meaningful comparison. In addition, a geological map shows predominantly age

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relations, while for useful geochemical comparisons, the different rock types, i.e., lithology,

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would be much more adequate, however such datasets are scattered and largely unavailable at

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the continental scale. In order to compare parent material related subgroups using boxplots,

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the information on the geological maps was combined with geochemical knowledge about

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materials which most likely provide specific and well defined geochemical signals for at least

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some elements. As a result, 10 geological parent material subgroups were defined for

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al., 2012a): alk: alkaline rock; chalk: calcareous rocks; granite: granitic bedrock; green:

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greenstone, basalt, mafic bedrocks; loess: loess; org: organic soil; other: unclassified bedrock;

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prec: predominantly Precambrian bedrock (granitic gneiss); quartz: soil developed on coarse-

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grained sandy deposits (e. g., the end moraines of the last glaciation); schist: schist. In

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addition, the relative proportions of six major lithological types were recalculated for Europe

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(Caritat and Reimann, 2012) based on the global rock lithology presented by Amiotte-Suchet

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et al. (2003). Among these major lithologies, plutonic and metamorphic rocks (39%) and

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shales (37%) dominate; carbonate rocks (14%) and sand-sandstones (9.5%) are significant,

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whereas felsic volcanic rocks and basalts (0.5% each, respectively) play a subordinate role.

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The boxplots on Figure 5 show the Ge concentrations in the Ap agricultural soil

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related to the different 10 parent materials defined above, and can be used to develop

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interpretation of the main features displayed on the geochemical maps. In general, the highest

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Ge median values in soil seem to correlate with parent materials represented by alkaline rocks

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and the lowest median correlates with coarse-grained sandy deposits. A large range of Ge

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concentrations can be observed for carbonate parent materials (with the lower median values)

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and in organic soils (relatively high median value and large span between minimum and

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maximum concentrations) which itself is an interesting phenomenon. This implies that these

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two classes either are not well defined or they present a complex system where Ge

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geochemical behavior can be additionally controlled by other soil parameters. Overall, these

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plots must be used with certain caution, as for example, while geology changes from north to

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south in Europe, the climate has a strong influence on soil geochemistry as well and therefore

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may give a supplementary imprint on the data. Finally, the boxplots display a wide overlap

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among some of the 10 defined types of bedrock.

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4.3 Spatial distribution of Ge in the GEMAS Ap and Gr agricultural soils

The spatial distribution of Ge in an aqua regia extraction in both the Ap (Fig. 6a) and

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Gr (Fig. 6b) maps is very similar. Furthermore, the maps in Figure 6 do not show a significant

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difference between northern and southern Europe (median close to 0.031 and 0.037 mg/kg,

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respectively), although, Ge concentrations in soil developed over the glacial sediments in

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northern and central Europe are generally low. One of the largest and most obvious patterns

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visible on the GEMAS geochemical maps for many elements (Reimann et al., 2014a, b;

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Ladenberger et al., 2015; Albanese et al., 2015) is the concentration break between northern

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and southern Europe. A comparison with the extent of the European ice sheets (Fig. 1c)

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demonstrates the close relationship of the geochemical pattern with the southern limit of the

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maximum extent of the glaciation. However, contrary to several other maps (Reimann et al.,

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2014a, b; Ladenberger et al., 2015; Albanese et al., 2015), the southernmost limit of the last

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glaciation is less visible for Ge. One of the reasons can be a large amount of samples with low

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Ge concentrations below the DL which smoothed the Ge distribution on the low-end side.

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Among more than 100 anomalies that can be marked on the Ap and Gr maps (Figs. 6a

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and b) 43 are listed and explained in Table 1 and only for Ap soils. These listed anomalies

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correspond to the Ge concentrations ranging between 0.094 and 0.21 mg/kg.

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Quite often anomalies appear to be associated with granitic intrusions and related

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sulphide mineralisation, e.g. in the northern Portugal and Spain in the Iberian massif, in the

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southern and northern Massif Central in France, in Sweden and Czech Republic. Polymetallic

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vein deposits with Sn-Ag and Ag-Pb-Zn in Massif Central (Noailhac-Saint-Salvy, France)

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were once the biggest producers of germanium (Cassard et al. 1996). Other vein deposits with

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germanium are known from Freiberg district and Harz mountains in Germany, Kutna Hora in

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Czech Republic, Sardinia in Italy and Kirki in Greece (Melcher and Buchholz, 2014).

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ACCEPTED MANUSCRIPT In Germany and France, elevated Ge concentrations occur in relation with Mesozoic to

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Tertiary sedimentary rocks. Carbonate-hosted sulphide deposits with Ge occur for example in

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Ireland (e.g. Lisheen, Navan, Tynagh) and in the Alps (e.g. Bleiberg; Melcher and Buchholz,

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2014).The alkaline volcanic rocks in Italy are also clearly marked by Ge anomalies and one

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anomaly occurs in the volcanic deposits of the Massif Central in France.

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The lack of correlation between TOC and Ge precludes a significant role of climate

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which otherwise can be observed in the Hg variability (Ottesen et al., 2013) and on P or Se

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maps (Reimann et al., 2014a, b). The numerous high Ge values marking almost the full length

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of the Norwegian coast, in Scotland and NW Spain may rather represent a geological

337

signature with many granitic intrusions. In Sweden and Finland the main sinks for Ge

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mobilised during weathering are glacial and postglacial clay deposits (e.g., the Central

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Scandinavian Clay Belt) which is expressed for instance by strong correlation between Ge

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and Al, K and to minor extent clay content in this area. Organic, humus-rich soil is another

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subordinate repository of Ge. However, it appears that lithology and mineralisation dominate

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the signal.

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Ge-enrichment in soil can also originate from the occurrence of coal and lignite

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(natural source), and the air-born deposition from fly ash (anthropogenic source) due to power

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production utilizing the coal deposits. The UK was once one of the first countries recovering

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Ge from fly ash in coal districts in Durham and Northumberland (Melcher and Buchholz,

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2014). High Ge concentrations are known from lignite deposits in Bulgaria and hard coal

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from the middle-German coal basin while lignite from western Germany has a low Ge content

349

(Melcher and Buchholz, 2014). However, in general, the distribution of Ge in GEMAS soil

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poorly correlates with the major brown coal and lignite deposits in Europe (e.g. in the UK,

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Czech Republic, Poland and Germany), which indicate that this source does not significantly

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contribute to the bulk germanium in agricultural soil at the continental scale. A possible

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Europe’s largest brown coal fired power plants. For many other elements the same

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observation was made: contamination is a small scale (local) process, while geology and

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climate dominate the geochemical maps at the continental scale.

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4.4 Ge distribution in the Baltic Soil Survey (BSS)

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The Baltic soil survey (BSS) was carried out in Norway, Sweden, Finland, Germany, Poland,

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Russia, Lithuania, Belarus, Latvia and Estonia (Reimann et al., 2000; 2003). Ge

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concentrations were determined by ICP MS using a near total 4 acid extraction, a method not

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fully comparable with those used in the GEMAS project.

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At the regional scale, there is a difference of a factor 2 in the median Ge-

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concentrations among the BSS participating countries. Sweden and Norway show the highest

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median (4.2 and 3.8 mg/kg), Belarus and Germany the lowest (both 2.3 mg/kg). The boxplots

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in Fig. 7 show the difference in the TOP/BOT (TOP: 0-25 cm, BOT: 50-75 cm, collected on

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regularly ploughed agricultural fields) ratio between all countries. Germanium is clearly

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enriched in the TOP-soils of Belarus, Germany, Poland, Russia and Sweden and clearly

368

depleted in the other 5 countries. In the cumulative distribution function CDF-diagram, the

369

lines for TOP-and BOT cross several times (Fig. 8). The overall median is slightly higher in

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the TOP-layer, while variation (min-max) larger in the BOT-layer. The BOT samples are

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characterized by a larger amount of outliers and considerably higher maximum values. The

372

correlation between the TOP and BOT-layer is only 0.58. This rather low correlation is

373

caused by Ge enrichment in the TOP-layer in countries like Sweden, Germany, Belarus,

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Poland and Russia, while Ge is depleted in the TOP-layer in e.g. Norway, Finland and

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Lithuania. Interestingly, the BSS Ge median values are clearly higher than the estimated Ge

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crustal abundance (1.35 mg/kg, Hu and Gao, 2008) and higher than the value for world soil

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reported by Koljonen (1992, value of 2.1 mg/kg). The correlation coefficient of other

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elements with Ge in the TOP-layer was only presented for elements for which the r-value was

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>0.5. In fact, germanium does, for example correlate (r>0.6) with all Rare Earth Elements

380

(not only Ce and La). The Ge BSS maps (Fig. 9) show a striking difference between the TOP- and BOT-

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horizon. The BOT layer is marked by considerably higher concentrations in many parts of the

383

Nordic countries, most pronounced in Norway and within the Caledonian mountain chain. In

384

central Norway, the pronounced BOT Ge anomaly marks the old Røros and Grong mining

385

areas. The Swedish soils also show almost exclusively high to median Ge-concentrations,

386

with a remarkable depletion in southern Sweden. In Finland, the southern tip of the country is

387

marked by a large Ge anomaly present in the BOT-layer which is controlled by the local

388

bedrock composed mainly of magmatic rocks (plutonic and volcanic), e.g. rapakivi granites

389

and the presence of numerous sulphide mineralisations. In general, there is a major break in

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Ge-concentrations between the Baltic Shield/Caledonides (Norway, Sweden and Finland) and

391

the Eastern and Western European Platform (Central and Eastern Europe) where low Ge

392

levels predominate.. In the southern part of the survey area (Poland), increasing Ge-

393

concentrations mark the border where the soil has developed on bedrock instead of

394

Quaternary deposits (including glacial deposits), i.e. the Sudetes (Variscan Orogeny) and

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Carpathian mountains (Alpine Orogeny).

396

6 – Conclusions

397

The GEMAS agricultural soil dataset of Europe provides an excellent base for studying

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chemical variations in soil composition at the continental scale related to various factors such

399

as lithology, climate, topography and soil texture. The distribution of Ge in European

400

agricultural (Ap) and grazing (Gr) soils gives a global view of element mobility and its

401

source(s) at the continental scale and helps to identify patterns that are related mainly to

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bedrock geology and weathering.

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Mapping Ge in agricultural and grazing land soil at the European scale at a sample density of 1 site per 2500 km2 delivered the following key results: -

The spatial distribution for Ge in the two different sample materials, Ap and Gr is very similar, highlighting that the low density sampling approach delivers robust and

407

reliable maps at the European scale.

408

-

409

The detection limit for Ge in an aqua regia extraction is at present still too high to deliver a complete dataset.

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The aqua regia extraction results from GEMAS project differ from the BSS survey

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which presents near-total concentrations. The roughly estimated extractability (based

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on a comparison of the BSS and GEMAS results) of Ge in aqua regia in the GEMAS

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samples may be as low as 1% and very selective (e.g. only certain minerals or coatings

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release Ge), and thus provides only partial information about the presence of Ge in

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soil. -

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The distribution of Ge in agricultural soil at the European scale is clearly dominated by geology and mineralisation, a likely anthropogenic source can only be assumed on

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a rather local scale at some few sites (coal fired power plant or smelter).

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-

pathfinder element for detecting sulphide mineralization (sulphides are soluble in aqua

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regia while for example Ge-bearing feldspar from granitic rocks – is not).

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Germanium as measured in an aqua regia extraction has potential to be used as a

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Finally, Zaunbrecher et al. (2015) suggested that Ge can be used in investigations of

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clay distribution at the continental scale. Results presented here show that at the

426

continental European scale, Ge is not preferentially enriched in clay-rich regions,

427

probably because the primary source of Ge does not exists in large clay-dominated

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ACCEPTED MANUSCRIPT sedimentary and river basins and certainly Ge is depleted in sandy soils. On the other

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hand, in Fennoscandia such a relation can be observed when the primary source of

430

germanium is the bedrock and sulphide mineralisation and the secondary source of Ge

431

occurs in glacial and postglacial clays as a result of remobilization and redeposition of

432

Ge from the primary source.. This phenomenon can be observed in central Sweden

433

and southern Finland, the region submerged under the sea after the last glaciation, and

434

highlighted by the strong correlation between Ge and Al and K, and the correlation

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between Ge and the clay content in these areas. -

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Thus, we can postulate that Ge in soil can be used as an indicator of clay fraction but under specific local conditions and at a scale that does not match that of a continental

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study.

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Acknowledgements

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The GEMAS project is a cooperative project of the EuroGeoSurveys Geochemistry Expert Group with

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a number of outside organisations (e.g., Alterra, The Netherlands; Norwegian Forest and Landscape

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Institute; Research Group Swiss Soil Monitoring Network, Swiss Research Station Agroscope

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Reckenholz-Tänikon, several Ministries of the Environment and University Departments of

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Geosciences, Chemistry and Mathematics in a number of European countries and New Zealand;

446

ARCHE Consulting in Belgium; CSIRO Land and Water in Adelaide, Australia). The analytical work

447

was co-financed by the following industry organisations: Eurometaux, European Borates Association,

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European Copper Institute, European Precious Metals Federation, International Antimony Association,

449

International Lead Association-Europe, International Manganese Institute, International Molybdenum

450

Association, International Tin Research Institute, International Zinc Association, The Cobalt

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Development Institute, The Nickel Institute, The (REACH) Selenium and Tellurium Consortium and

452

The (REACH) Vanadium Consortium. The Directors of the European Geological Surveys, and the

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additional participating organisations, are thanked for making sampling of almost all of Europe in a

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tight time schedule possible. The Federal Institute for Geosciences and Natural Resourced (BGR), the

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Geological Survey of Norway and SGS (Canada) are thanked for special analytical input to the

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project.

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References

459

Aitchison, J., 1986. The Statistical Analysis of Compositional Data. Chapman & Hall, London, 416

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RI PT

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pp.

461

Albanese, S., Sadeghi, S., Lima, A., Cicchella, D., Dinelli, E., Valera, P., Falconi, M., Demetriades,

462

A., De Vivo, B. and The GEMAS Project Team, 2015. GEMAS: Chromium, Ni, Co and Cu in

463

agricultural and grazing land soil of Europe. J. Geochem. Explor.154, 81-93.

Amiotte Suchet, P., Probst, J.-L., Ludwig, W., 2003. Worldwide distribution of continental rock

465

lithology: Implications for the atmospheric/soil CO2 uptake by continental weathering and

466

alkalinity river transport to the oceans. Global Biogeochemical Cycles 17, 1038-1051.

M AN U

SC

464

467

Angerer, G., Marscheider-Weidemann, Lüllmann, A., F., Erdmann, L., Scharp, M., Handke, V.,

468

Marwede, M., 2009. Rohstoffe für Zukunftstechnologien. Einfluss des branchenspezifischen

469

Rohstoffdebarfs in Rohstoffintensiven Zukunftstechnologien auf die zukünftige Rohstoffnachfrage.

470

ISI-Schriftenreihe

471

Innovationsforschung. Fraunhofer IRB-Verlag, 330-340.

473 474 475

Fraunhofer

Institut

für

System-

und

Bernstein, L.R.1985. Germanium geochemistry and mineralogy. Geochim. Cosmochim. Acta 49, 2409-2422.

TE D

472

’’Innovationspotenziale’’,

Burton, J.D., Culkin, F., Riley, J.P. 1959. The abundances of gallium and germanium in terrestrial materials. Geochim. Cosmochim. Acta 16, 151-180. Caritat, P. de, Reimann, C., NGSA Project Team and GEMAS Project Team. 2012. Comparing results

477

from two continental geochemical surveys to world soil composition and deriving Predicted

478

Empirical Global Soil (PEGS2) reference values. Earth Planet. Sci. Lett. 319-320, 269–276.

EP

476

Cassard, D., Chabod, J.C., Marcoux, E., Bourgine, B., Castaing, C., Gros, Y., Kosakevich, A., Moisy,

480

M., Viallefond, L., 1996. Mise en place et origine des minéralisations du gisement à Zn, Ge, Ag,

481

(Pb, Cd) de Noailhac-Saint-Salvy (Tarn, France). Chro. Rech Min 514, 3–37.

AC C

479

482

Davidson, C.M., Thomas, R.P., McVey, S.E., Perala, R., Littlejohn, D., Ure, A.M. 1994. Evaluation of

483

a sequential extraction procedure for the speciation of heavy metals in sediments. Anal. Chim Acta

484

291, 277-286.

485 486

De Argollo, R., Schilling, J.-G. 1978. Ge-Si and Ga-Al fractionation in Hawaiian volcanic rocks. Geochim. Cosmochim. Acta 42, 623-630.

487

Dürr, H.H., Meybeck, M., Dürr, S.H. (2005): Lithologic composition of the Earth’s continental

488

surfaces derived from a new digital map emphasizing riverine material transfer, Global

489

Biogeochemistry Cycles, 19(4): 1-23.

19

ACCEPTED MANUSCRIPT 490

EC, 2006. Regulation (EC) No 1907/2006 of the European Parliament and of the Council of 18

491

December 2006 concerning the Registration, Evaluation, Authorisation and Restriction of

492

Chemicals (REACH), establishing a European Chemicals Agency, amending Directive 1999/45/EC

493

and repealing Council Regulation (EEC) No 793/93 and Commission Regulation (EC) No 1488/94

494

as well as Council Directive 76/769/EEC and Commission Directives 91/155/EEC, 93/67/EEC,

495

93/105/EC and 2000/21/EC. Official Journal of the European Union L 396, 1-849.

497

El Wadarni, S.A. 1957. On the geochemistry of germanium. Geochim. Cosmochim. Acta 13, 5-19.

RI PT

496

Goldschmidt, V.M. 1954. Geochemistry, Oxford University, London, 730pp. Goldschmidt, V.M. 1954. Geochemistry, Oxford University, London, 730pp.

499

Goodman, S., 1988. Therapeutic effects of organic germanium. Med Hypoth 26, 207-215.

500

Guberman, D.E., 2015. Germanium. In: U.S. Geological Survey, 2015, Mineral commodity

501

SC

498

summaries 2015: U.S. Geological Survey, 64-65, http://dx.doi.org/10.3133/70140094 Günther, A., Reichenbach, P., Malet, J.-P., Van Den Eeckhaut, M., Hervás, J., Dashwood, C.,

503

Guzzetti, F. 2013. Tier-based approaches for landslide susceptibility assessment in Europe.

504

Landslides 10, 529–546.

505 506 507 508

M AN U

502

Haller, E.E., 2006. Germanium: from its discovery to SiGe devices. Materials Science in Semiconductor Processing 9, 408-422.

Harris, P.G. 1954. The distribution of germanium among coexisting phases of partly glassy rocks. Geochim. Cosmochim. Acta 6, 185 - 195.

Hartwich, R., Baritz, R., Fuchs, M., Krug, D., Thiele, S. (2005): Explanation to the Soil Regions Map

510

of the European Union and Adjacent Countries 1: 5 000 000 (Version 2.0). European Soil Bureau

511

Research reports, Luxembourg, 122 pp.

513 514 515

Höll, R. Kling, M., Schroll, E. 2007. Metallogenesis of germanium—A review. Ore Geol. Rev. 30, 145–180.

EP

512

TE D

509

Hu, Z., Gao, S. 2008. Upper crustal abundances of trace elements: A revision and update. Chem. Geol. 253, 205–221.

Jorgenson J.D., 2002. Germanium. U.S. Geological Survey Minerals Yearbook - 2002, pp32.1 – 32.5.

517

Koljonen, T. (Editor). 1992. The Geochemical Atlas of Finland, Part 2: Till. Geological Survey of

518

AC C

516

Finland, Espoo, Finland, 218 pp.

519

Kriete, C., 2011. Results of the GEMAS ring test as supplied to the participating laboratories. BGR-

520

Report on the GEMAS project proficiency test. Bundesanstalt für Geowissenschaften und

521

Rohstoffe, Hannover, p. 57.

522 523

Kurtz, A.C., Derry, L.A., Chadwick, O.A. 2002. Germanium–silicon fractionation in the weathering environment. Geochim. Cosmochim. Acta 66, 1525–1537.

20

ACCEPTED MANUSCRIPT 524

Ladenberger, A., Demetriades, A., Reimann, C., Birke, M., Sadeghi, M., Uhlback, J., Andersson, M.,

525

Jonsson, E. and the GEMAS Project Team. 2015. GEMAS: Indium in agricultural and grazing land

526

soil of Europe – its source and geochemical distribution patterns. J. Geochem. Explor. 154, 61–80.

527 528

Lugolobi, F., Kurtz, A.C., Derry, L.A. 2010. Germanium–silicon fractionation in a tropical, granitic weathering environment. Geochim. Cosmochim. Acta 74, 1294–1308. Madrid, F., Reinoso, R., Florido, M.C., Dıaz Barrientos, E., Ajmone-Marsan, F., Davidson, C.M.,

530

Madrid, L. 2007. Estimating the extractability of potentially toxic metals in urban soils: A

531

comparison of several extracting solutions. Env. Poll. 147, 713-722.

RI PT

529

Melcher, F., Oberthur, T., Rammlmair, D. 2006. Geochemical and mineralogical distribution of

533

germanium in the Khusib Springs Cu–Zn–Pb–Ag sulfide deposit,Otavi Mountain Land, Namibia.

534

Ore Geol. Rev. 28, 32–56.

535 536

SC

532

Melcher, F., Buchholz, P., 2014. Germanium. In: Gunn G. (Ed) Critical Metals Handbook. BGS, John Wiley and Sons Ltd, Chichester, 177-203.

Négrel, Ph., Sadeghi, M., Ladenberger, A., Reimann, C., Birke, M., the GEMAS Project Team. 2015.

538

Geochemical fingerprinting and source discrimination of agricultural soils at continental scale.

539

Chem. Geol. 396, 1–15.

M AN U

537

540

Ottesen, R.T., Birke, M., Finne, T.E., Gosar, M., Locutura, J., Reimann, C., Tarvainen, T. and the

541

GEMAS team. 2013. Mercury in European agricultural and grazing land soils. App. Geochem. 33,

542

1-12.

Reimann, C., Kriete, C., 2014. Trueness of GEMAS Analytical Results - the Ring Test, in: Reimann,

544

C., Birke, M., Demetriades, A., Filzmoser, P., O'Connor, P. (Eds.), Chemistry of Europe’s

545

Agricultural Soils. Part A: Methodology and Interpretation of the GEMAS Data Set. Schweizerbart

546

Science Publishers, Stuttgart, pp. 61-66.

TE D

543

Reimann, C., Siewers, U., Tarvainen, T., Bityukova, L., Eriksson, J. Gilucis, A., Gregorauskiene, V.,

548

Lukashev, V., Matinian, N.N., Pasieczna, A. 2000. Baltic soil survey: total concentrations of major

549

and selected trace elements in arable soils from 10 countries around the Baltic Sea. Sci. Total

550

Environ. 257, 155-170.

AC C

EP

547

551

Reimann, C. Siewers, U., Tarvainen, T., Bityukova, L., Eriksson, J. Giucis A.; Gregorauskiene, V.,

552

Lukashev, V.K., Matinian, N.N., Pasieczna, A. 2003. Agricultural Soils in Northern Europe. A

553

Geochemical Atlas. ISBN 978-3-510-95906-8 279pp.

554

Reimann, C., Demetriades, A., Eggen, O.A., Filzmoser, P., the EuroGeoSurveys Geochemistrv Expert

555

Group, 2011. The EuroGeoSurveys GEochemical Mapping of Agricultural and grazing land Soils

556

project (GEMAS) Evaluation of quality control results of total C and S, total organic carbon

557

(TOC), cation exchange capacity (CEC), XRF, pH, and particle size distribution (PSD) analysis.

558

NGU Report No. 2011.043, 90pp.

21

ACCEPTED MANUSCRIPT 559

Reimann, C., Caritat, P. de, and GEMAS team and NGSA team. 2012. New soil composition data for

560

Europe and Australia: Demonstrating comparability, identifying continental-scale processes and

561

learning lessons for global geochemical mapping. Sci. Total Environ. 416, 239-252. Reimann, C., Filzmoser, P., Fabian, K., Hron, K., Birke, M., Demetriades, A., Dinelli, E.,

563

Ladenberger, A., and GEMAS team. 2012a. The concept of compositional data analysis in practice-

564

-total major element concentrations in agricultural and grazing land soils of Europe. Sci. Total

565

Environ. 426, 196-210.

RI PT

562

566

Reimann, C., Flem, B., Fabian, K., Birke, M., Ladenberger, A., Négrel, Ph., Hoogewerff, J. 2012b.

567

Lead and lead isotopes in agricultural soils of Europe - the continental perspective. App. Geochem.

568

27, 532–542.

Reimann, C., Birke, M., Demetriades, A., Filzmoser, P., O'Connor, P. (Eds.), 2014a. Chemistry of

570

Europe's Agricultural Soils - Part A: Methodology and Interpretation of the GEMAS Dataset.

571

Geologisches Jahrbuch (Reihe B), Schweizerbarth, Stuttgart, 528pp.

SC

569

Reimann, C., Birke, M., Demetriades, A., Filzmoser, P., O'Connor, P. (Eds.), 2014b. Chemistry of

573

Europe's Agricultural Soils - Part B: General Background Information and Further Analysis of the

574

GEMAS Dataset. Geologisches Jahrbuch (Reihe B), Schweizerbarth, Stuttgart, 352pp.

575 576

M AN U

572

Rosenberg, E. 2009. Germanium: environmental occurrence, importance and speciation. Rev Environ Sci Biotechnol 8, 29–57.

Rudnick, R.L., Gao, S., 2003. Composition of the Continental Crust. In: Holland, H.D., Turekian,

578

K.K. (eds-in-chief), Treatise on Geochemistry Volume 3: Rudnick, R.L. (ed.), The Crust, 1–64.

579

Elsevier-Pergamon, Oxford.

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Saaltink, R., Griffioen, J., Mol, G., Birke, M. and the GEMAS team. 2013. Geogenic and agricultural

581

controls on the geochemical composition of European agricultural soils. J. Soils Sediments, 14,

582

121–137.

EP

580

Sadeghi, M., Petrosino, P., Ladenberger, A., Albanese, S., Andersson, M., Morris, G., Lima, A.M., De

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Vivo, B. and the GEMAS team. 2013. Ce, La and Y concentrations in agricultural and grazing-land

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soils of Europe. J. Geochem. Explor. 133, 202-213.

AC C

583

586

Scheib, A.J, Flight, D.M.A., Birke, M., Tarvainen, T., Locutura, J.and GEMAS Project Team. 2012.

587

The geochemistry of niobium and its distribution and relative mobility in agricultural soils of

588

Europe. Geochemistry: Exploration, Environment, Analysis 12, 293-302.

589 590 591 592

Scribner, A.M., Kurtz, A.C., Chadwick, O.A. 2006. Germanium sequestration by soil: Targeting the roles of secondary clays and Fe-oxyhydroxides. Earth and Planetary Science Letters 243, 760–770. Tarvainen, T., Albanese, S., Birke, M., Ponavic, M. Reimann, C. and the GEMAS team. 2013. Arsenic in agricultural and grazing land soils of Europe. App. Geochem. 28, 2-10.

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Vilà, M., Martínez-Lladó, X. 2015. Approaching earth surface geochemical variability from

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representative samples of geological units: The Congost River basin case study. J. Geochem.

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Explor. 148, 79–95.

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Wedepohl, K.H. 1978. Handbook of Geochemistry. Springer-Verlag Berlin.

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Zaunbrecher, L.K., Elliott, W.C., Wampler, J.M., Perdrial, N., Kaplan D.I. 2015. Enrichment of

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cesium and rubidium in weathered micaceous materials at the Savannah River Site, South Carolina.

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Figure captions

607 Figure 1. Modified from Négrel et al., 2015. (a) Map of parent materials in Europe showing

609

the distribution of various lithologies across the continent (modified from Gunther et al.,

610

2013 and adapted from Négrel et al., 2015). (b) Sample locations of the ploughed

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agricultural soil sample sites (dots); (Ap-samples as example, n=2108) from the

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EuroGeoSurveys GEMAS Project participating countries are shaded dark grey. Map

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projection: Lambert Azimuthal Equal Area (ETRS_1989_LAEA), with central meridian at

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10°. (c) Generalised geological map of Europe with major lithotectonic units, Variscan and

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Alpine belts, Transeuropean Suture Zone (TESZ) and the extension of maximum glaciation

616

(modified from Reimann et al., 2012b).

617

SC

RI PT

608

Figure 2. Combination plot of histogram, density trace, one-dimensional scatter-diagram and

619

boxplot of the Ge distribution in European Ap and Gr soil samples following an aqua regia

620

extraction.

M AN U

618

621

Figure 3. Cumulative probability plot of aqua regia extractable Ge concentrations in ploughed

623

agricultural (Ap) and grazing land (Gr) samples. X-axis truncated to 99th percentile value

624

for Gr data.

625

TE D

622

Figure 4. Boxplots comparing Ge in agricultural (Ap, red) and grazing (Gr, green) land soils

627

in the countries participating in this survey. The countries are sorting according to

628

decreasing median concentrations. AUS: Austria, BEL: Belgium, BOS: Bosnia and

629

Herzegovina, BUL: Bulgaria, CRO: Croatia, CYP: Cyprus, CZR: Czech Republic, DEN:

630

Denmark, EST: Estonia, FIN: Finland, FOM: Former Yugoslavian Republic of Macedonia

631

(FYROM), FRA: France, GER: Germany, HEL: Hellas, HUN: Hungary, IRL: Republic of

632

Ireland, ITA: Italy, LAV: Latvia, LIT: Lithuania, LUX: Luxemburg, MON: Montenegro,

633

NEL: The Netherlands, NOR: Norway, POL: Poland, PTG: Portugal, SIL: Switzerland,

634

SKA: Slovakia, SLO: Slovenia, SPA: Spain, SRB: Serbia, SWE: Sweden, UKR: Ukraine,

635

UNK: United Kingdom. Numbers correspond to the number of samples per country. Red

636

and green lines correspond to the median of Ge in Ap (red) and Gr (green) samples.

AC C

EP

626

637 638

Figure 5. Boxplots for the aqua regia extractable Ge concentrations (mg/kg) in Ap soil

639

samples according to soil parent material: alk: alkaline rock; chalk: calcareous rock; 24

ACCEPTED MANUSCRIPT 640

granite: granitic bedrock; green: greenstone, basalt, mafic bedrock; loess: loess; org:

641

organic soil; other: unclassified bedrock; prec: predominantly Precambrian bedrock

642

(granitic gneiss); quartz: soil developed on coarse-grained sandy deposits (e.g., the end

643

moraines of the last glaciation); schist: schist. Red diamonds correspond to outliers

644 Figure 6. Soil geochemical maps for Ge concentrations in aqua regia extraction: (a) ploughed

646

agricultural soils (Ap, n=2108) and (b) grazing land soils (Gr, n=2024). Mapping tool

647

IDW, cell size = 10 000 m, search radius = 80 000 m.

RI PT

645

648

Figure 7. Boxplots for TOP horizon comparing Ge in the countries participating in the Baltic

650

soil survey (BSS). The countries are identified by a three digit code (BEL: Belarus, POL:

651

Poland, SWE: Sweden, GER: Germany, RUS: Russia, LAV: Latvia, NOR: Norway, EST:

652

Estonia, FIN: Finland and LIT: Lithuania). To focus on the main body of data the outliers

653

are not shown in the plot. #NUMBER corresponds to the number of samples analyzed per

654

country. Modified from Reimann et al., 2003.

M AN U

SC

649

655

Figure 8. Cumulative probability plot and combination plot of histogram, density trace, one-

657

dimensional scatter-diagram and boxplot of the Ge concentrations for topsoil (TOP) and

658

subsoil (BOT) of the Baltic soil survey (BSS). Modified from Reimann et al., 2003.

TE D

656

659

Figure 9. Soil geochemical maps for Ge concentrations in a near total (4 acid, including HF)

661

extraction: (a) topsoil TOP (Ap-horizon, n=750) and (b) subsoil BOT (bottom samples,

662

usually B- or C-horizon, n=750) the Baltic soil survey (BSS). Modified from Reimann et al.,

663

2003.

AC C

664

EP

660

665

Table 1. Explanation of the most prominent aqua regia extractable Ge anomalies in

666

agricultural soil (Ap; 0–20 cm) listed in Fig. 6a. These listed anomalies correspond to the

667

Ge concentrations ranging between 0.094 and 0.21 mg/kg.

25

ACCEPTED MANUSCRIPT 1 Geographical area

Explanation (possible sources)

France France

1 2

Southern Massif Central Southern Massif Central

France France France France France France Germany

3 4 5 6 7 8 9

Cantal, Massif Central Northern Massif Central Southern Paris Basin NE Paris Basin NE Paris Basin Charente SSE Dillenburg

Germany

10

East Black Forest

Czech Republic Slovenia

11 12

Moldanubicum Črnomelj

Italy

13

Veneto Region

Croatia/Bosnia Herzegovina/ Montenegro

14

Montenegro Serbia/FYROM/ Bulgaria/N Hellas (Macedonia)

15 16

Radošić (Croatia) /StrujićiRavno (Bosnia & Herzegovina) /Grahovo (Montenegro) Grahovo-Berane Konjino (Serbia) Hamzali (FYROM)

Lithology: Mons Granite Lithology: Aigoual Granite. Mineralisation: Pb–Zn deposits Lithology: Basalts Lithology: St Genest Granite Lithology: Jurassic sedimentary rocks Lithology: Lias sedimentary rocks Lithology: Lias sedimentary rocks Lithology: Jurassic sedimentary rocks Lithology: Sedimentary hematite occurences Mineralisation: Sedimentary Fe-Mn mineralisations Lithology: High-potassic plutonites Lithology/Weathering: residual soil formed on limestone, karst areas with terra rossa. Enrichment in several elements: Cd, Ba, Be,Co, Cs, Ga, Gr, Hg, In, Mn, P, Sr, Tl, Y Soil type: Floodplain sediment deposits related to the Piave river Lithology: Carbonate dominated bedrock with the old residual soil (terra rossa)

Hellas

17

Italy

SC

M AN U

TE D

18

AC C

Hellas

RI PT

Anomaly No

EP

Country

Kos Island

Eastern Sterea

19

Sardinia

Italy

20

Apulia Region

Italy Italy Italy

21 22 23

Campania Region Latium Region Tuscany Region

Soil type: Old residual soil (terra rossa) Pb-Zn deposits in Karamanica (Serbia); and porphyry Cu-Au at Ilovitza (FYROM); three mines and flotation plants for Pb and Zn: Zletovo, Sasa and Toranica (FYROM) Lithology: Recent alluvial sediments; granite nearby, pyrite-Cu mineralization north of Lamia. Lithology: Recent alluvial sediment on limestone bedrock; ophiolite and Fe-Ni mineralisation nearby Mineralisation: Epithermal Cu+Au deposits and porphyry Cu deposits (related to Oligocene-Miocene intrusions) in NW and SW parts of Sardinia. Pb-Zn (±Ag±Cd) deposits in the Iglesiente district, one of the oldest mining districts in the world (production dates back to pre-Roman time), with more than 50 major deposits known (e.g. Pb, Ag, Cu, Zn, Ba) Mineralisation: Presence of small deposits of bauxite in limestone Lithology: alkaline Volcanic rocks Lithology: alkaline volcanic rocks Lithology: flysch sedimentary rocks

1

ACCEPTED MANUSCRIPT

Spain/Portugal

26

Iberian Massif

Spain

27

Galicia

Great Britain

28

Leicester

Great Britain

29

Scotland

Norway

30

SW Norway Setesdal

Norway

31

Sweden Sweden Sweden

32 33 34

Sweden

35

Sweden

36

Sweden Sweden

37 38

Oslo

Småland

TE D

Mälaren region

Gävle (Northern Uppland) Langdal

Västerbotten Southern Norrbotten (Boden)

EP 39

AC C

Finland

Finland

40

German/Polish/ Czech border

41

Ukraine

42

Lithology: Floodplain sediment deposits Mineralisation: Massive sulphide deposits of the Spanish part of the Iberian Pyrite Belt (more than 150 polymetallic massive sulphide deposits). Small veins and disseminations with Cu-Zn-Ag mineralisation in schist, greywacke and rhyolite Mineralisation: mineralisation (Sn-AgW-As) in Variscan granite Mineralisation: anomalies which are to mineralisation zones in a shear zone Lithology: Calcareous sedimentary ironstone, enriched in Cr, V and As. Mineralisation: Minor Zn mineralisation. Industry: Zinc plating factories in Leicester, former steel factory in Corby. Mineralisation: Sulphide mineralisations in Caledonian rocks Lithology: Multi-element anomaly (REE enrichment) related to Western gneiss region. Mineralisation: Sauda Sinkgruver (Birkeland sinkgruver) in Rogaland – Sveconorwegian Massive Sphalerite Ore. Industry: Slightly enhanced values can be related to Odda Norway's largest Zn smelter. Lithology: Oslo rift, black shales as additional Ge source Lithology: gabbro-granitoid-syenitoid Skarn with sulphide mineralization Lithology: gneiss and paragneiss; glacial clay and postglacial clay deposits Lithology:granit, rhyolite, postglacial clay Lithology: Greywacke, migmatite, granite Lithology: granite, Zn-Cu mineralisation Lithology: Greywacke, migmatite, granite. Numerous mineralisations with Fe, Zn, Cu, Au Soil type: Organic-rich soil. Mineralisation: Close to Au-Cu, W (Tampere) mineralisation and Ni-Cu mineralisation in mafic rocks Soil type: Clay-rich soil. Mineralisation: numerous Fe and Zn mineralisation with magnetite and sphalerite, Cu-rich quartz veins, Ni-Cu (Co) mineralisations in ultramafic and mafic rocks, felsic volcanic rocks with Cu-Zn-Pb (Au-Ag) mineralisation Mineralisation: location of one or Europe’s largest brown coal fired power plants Lithology: sedimentary rocks with anomalous concentrations of Hg, Ba,

RI PT

Romagna Region Central Spain

SC

24 25

M AN U

Italy Spain

Hirvensalmi

Southern Finland

Carpathians

2

ACCEPTED MANUSCRIPT Austria

2

43

Oetztal Alps (Tyrol)

Cd and F related to Alpine orogenesis Mineralisation: polymetallic Cu-Fe-ZnPb mineralisation/small scale mining sites in the Oetztal nappe unit (Upper Austroalpine basement)

Table 1

AC C

EP

TE D

M AN U

SC

RI PT

3

3

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT Germanium concentration of European soils in aqua regia extraction.

-

Agricultural soil dataset of Europe (GEMAS) allows studying the large scale variations.

-

Distribution of Ge in European soils is clearly dominated by geology and mineralization.

-

Ge measured in aqua regia extraction in soils has potential to detect sulphide mineralization

AC C

EP

TE D

M AN U

SC

RI PT

-