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The mineralogical composition of soil horizons in different soil types of different ages was estimated by applying the NORMA software, which was developed originally for calculating the normative mineralogical composition of young podsols. Ten soil profiles from six sites in NW Russia, two in Finland, and one in NE Norway were sampled in 1999 as a part of the pilot phase of a large geochemical mapping project. Total element concentrations were determined from the <2 mm fraction by XRF from powdered pellets for Al, Ca, Cr, Fe, K, Mg, Mn, Na, P, S, Si, Ti, and Zr, and for Ba by ICP-AES after HF+HClO4 extraction. Extractable concentrations for Al, Ca, Cr, Fe, K, Mn, Mg, Na, P, S, Ti, Zr, and Ba were determined by ICP-MS or ICP-AES after aqua regia (a 1:3 mixture of strong HCl and HNO3) extraction. Total C was determined using a thermal conductivity detector from a sample burned in an O2 stream. The NORMA software was used to calculate the percentage of normative soluble minerals pyrite, apatite, titanite, calcite, biotite, chlorite, weathered albite, hydrous Al-silicate, goethite and soluble residue. The percentages of non-soluble normative minerals rutile, hornblende, K-feldspar, albite, anorthite, tremolite, wollastonite, kaolinite, magnetite, zircon, quartz, carbon (graphite), and non-soluble residue were calculated after soluble minerals.The calculated mineralogical composition of C-horizon samples in each profile reflected the known geological composition of the bedrock from which the soil parent material was derived during geological processes. Secondary minerals including goethite and hydrous Al-silicates, were detected in upper soil horizons reflecting the development of soils. Rather than age, the local bedrock geology together with the mineralogical composition and chemical properties of the parent material proved to be the controlling factor in the formation of secondary minerals. The results showed that the NORMA method can be used in defining the mineralogy of soil horizons in a large variety of soil types. 相似文献
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Reijo Salminen Igor Bogatyrev Victor Chekushin Sergey P. Glavatskikh Virgilija Gregorauskiene Heikki Niskavaara Lubov Selenok Markku Tenhola Olga Tomilina 《Geostandards and Geoanalytical Research》2004,28(2):333-341
The geochemical baselines of nickel and chromium were studied from the data produced by the Barents Ecogeochemistry project, a large international regional geochemical mapping exercise. The project surveyed major and trace element distributions in stream water, organic and mineralogically-modified soil horizons, and terrestrial moss in the northwestern part of Russia and in Finland. Other materials were collected during the pilot phase and later from thirty special sites. The results on respective materials by XRF, ICP-MS and ICP-AES showed that both geological and anthropogenic factors have an influence on the geochemical baseline concentrations of Ni and Cr in organic soil and stream water. The main explanation of the observed distribution patterns in terrestrial moss is human activity, but geological factors can also affect the baselines. The variation of geochemical baselines in the mineral-rich soil horizon depends only on variations in bedrock. The mineralogy of samples mainly controls the leachability properties of soil samples. 相似文献
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Since 1980 the main goal of geochemical investigations in Lithuania has been the estimation of technogene changes of microelements in the earth's surface sediments. For this purpose the geochemical mapping at various scales has been employed: at regional scale (1:2,500,000-1:500,000), at large scale (1:50,000-1:25,000), and at local scales 1:10,000-1:1000. The most important tasks are to determine and to establish the geochemical background for technogene changes in the topsoil layer and in the water reservoir bottom sediments. When mapping the zones of increased technogenical load the increase of concentration for most microelements in soils (ground) and in water reservoirs were established. Zn, Pb, Cu, Sn. Ag, Cr and Ni are the main elements-pollutants of these zones, concentrations of which exceed the background values from a few up to a dozen times. In certain cases their concentrations and the concentrations of specific elements, such as Sb, Bi. Ce, La, exceed thousands times the background value. At such zones the danger of pollution is increased due to the occurrence of mobile and potentially mobile toxic elements. During the soil mapping within the towns and factories not only the concentration of elements and the associations of elements-pollutants have been ascertained, but also the approximate contamination dangerous for biota -the total index of contamination (Zs) — has been calculated. The additional index that shows dangerous pollution is the maximum permissible by general sanitary concentration of chemical elements in soil (MPLCs) used in Lithuania. At some extremely contaminated zones (Zs > 128) the migration forms of toxic elements were determined by AAS-ES (gradual extraction using reagents of various acidity). The geochemical mapping data are used for the land-use, for the selection of geochemical monitoring polygons, hydrochemical. ecomedical and other investigations. 相似文献
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