Iron Oxides As Weathering Indicator and the Origin of Luvisols from the Vistula Glaciation Region in Poland
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J Soils Sediments (2016) 16:396–404 DOI 10.1007/s11368-015-1201-8 SOILS, SEC 2 • GLOBAL CHANGE, ENVIRON RISK ASSESS, SUSTAINABLE LAND USE • RESEARCH ARTICLE Iron oxides as weathering indicator and the origin of Luvisols from the Vistula glaciation region in Poland Hanna Jaworska1 & Halina Dąbkowska-Naskręt1 & Mirosław Kobierski1 Received: 10 March 2015 /Accepted: 9 July 2015 /Published online: 30 July 2015 # The Author(s) 2015. This article is published with open access at Springerlink.com Abstract in luvic horizons, while the profile distribution of iron is sim- Purpose The aim of the research was to determine the effect ilar to the distribution of clay. The (Fed/Fet) ratio indicates a of lithogenic and pedogenic processes on the formation of low degree of weathering; the highest values were observed in Luvisols from the area of Vistula glaciation on the base of argic (Bt) horizons, which confirms the effect of the process profile distribution of iron oxides and total iron in relation to of pedogenesis on the value of that index. In the soils investi- texture and physicochemical properties. The indices of gated, crystalline iron oxides generally dominate over the weathering of the soil material in genetic horizons were cal- amorphous forms. The mineralogical composition of clay culated, and changes in the content and forms of iron oxides fraction separated from the upper part of soils was different were evaluated. as compared to the underlying material. Materials and methods The predominant type of soil in the Conclusions The results of the study showed that iron con- study area is Luvisols under agricultural use, formed from silt tents (together with the other indicators) and its forms can be formations on loam. The analyses were made applying the used to distinguish soil layers of different origin. The depth following methods: grain size composition using the sieve distribution of Fed,Feo and Fet within soil profiles indicates method and hydrometer method, the interpretation of the re- that the soil material may be of different lithogenic origin in sults was performed according to the World Reference Base the studied pedons. for Soil Resources classification, the pH of soils was measured with the potentiometric method, C-organic with the Walkley- Keywords Iron oxides . Lithogenesis . Luvisols . Black dichromate method, the content of the following iron Pedogenesis . Vistula glaciation forms was determined (total iron (Fet) after the mineralization of soils in the mixture of HF and HClO4 acids), free iron oxides were extracted using dithionite-citrate-bicarbonate 1 Introduction method, and amorphous iron oxides after the ammonium ox- alate extraction (using the Philips 9100PU apparatus). The The Pleistocene deposits formed as a result of Scandinavian clay mineralogy was estimated by X-ray diffraction analysis. continental glaciations cover much of northern and central Results and discussion It was observed that total iron enrich- Poland. The Vistula glaciation in Poland is consistent with ment occurs in argic horizons accompanied by iron depletion the Weichsel glaciation in Germany, the Warta glaciation (Lindner 1984) in the eastern part of Europe, and the Responsible editor: Fabio Scarciglia Wisconsin glaciation (Flint 1971) in North America and ac- counts for the formation of glacial deposits with various mor- * Hanna Jaworska phological and physicochemical properties. Date ranges for [email protected] the Poznań phase and Kujawsko-Dobrzynska subphase are 18400kaBP (Wysota et al. 2008). The Luvisols is formed dur- ń 1 Department of Soil Science and Soil Protection, Faculty of ing the Kujawy-Dobrzy subphase of the Vistula glaciation Agriculture and Biotechnology, UTP University of Science and demonstrating a morphological profile variation, which could Technology, Bernardyńska 6 St, 85-029 Bydgoszcz, Poland be due to the processes of lithogenesis and pedogenesis. The J Soils Sediments (2016) 16:396–404 397 soil formation processes in the Luvisol profiles result in the stage (Lindner 1992). Luvisols (IUSS Working Group WRB differentiation of the chemical and mineralogical composition 2007) are predominant and under agricultural use, formed of soil material (Ranney and Beatty 1969). from silt formations on loam, with the following genetic ho- One of the generally accepted methods in research on soil rizon sequence: Ap-Et-Bt-C. Soil texture and the morphology genesis is the analysis of iron forms, depending on the direction of soil pedons suggest a lithological discontinuity within soil of the soil-forming processes, their type and intensity (Blume profiles in the region. Selected profiles were located on the flat and Schwertmann 1969; Cornell and Schwertmann 2003). The area of ground moraine plane formed during the Poznań Phase iron compounds, especially their complex associations with hu- of the Vistula Glaciation (Lindner 1984;Marks2002). The mus colloids, determine the profile distribution of other elements samples for analyses were taken from the each genetic horizon (Tack et al. 1997) in soils. They affect the colour of soils and are of seven profiles. The location of the soil profiles (P1– indicators of their properties (Kabata-Pendias and Pendias Zarzeczewo; P2–Glewo; P3–Dyblin; P4–Strachoń;P5– 2010). Soils containing goethite are yellow or brown. Mokowo; P6–Grochowalsk; P7–Bachorzewo) was deter- Ferrihydrite is dark reddish-brown. Variations in crystal size mined by using a GPS system (Fig. 1, Table 1). and morphology may cause variations in these mineral- The analyses were made applying the following methods: specific colours. With decreasing particle size, the colour of grain size composition using the hydrometer method, based goethite changes from yellow for crystals in the micrometre size on Stoke’s law governing the rate of sedimentation of particles range to dark brown for crystals of ca. 0.01 μm in length. Mn for suspended in water, the interpretation of the results is based on Fe substitution causes goethite to develop on olive (1–6%Mn) the World Reference Base for Soil Resources classification to blackish colour (10 % Mn) (Schwertmann and Cornell 1991). (IUSS Working Group WRB 2007), the pH of soils was mea- Iron dynamics can be studied by different extractions. The ratio sured with the potentiometric method (pH in KCl −3 of oxalate to dithionite-extractable iron (Feo/Fed) indicates the (1 mol dm ) and pH in H2O), C-organic with the Walkley- degree of iron oxide crystallinity and can be used as a reliable Black dichromate method, and the content of the following indicator of soil age (McFadden and Hendricks 1985). Hence, iron forms was determined: the Feo/Fed ratio tends to decrease with soil age (Moody and Graham 1995). The absence of a clear time trend of Feo/Fed ratio – Total iron (Fet) after the mineralization of soils in the can be explained by other factors (climatic conditions, parent mixture of HF and HClO4 acids (Crock and Severson material, redox processes and organic matter content) having 1980) greater impact on the Feo/Fed ratio than the time factor. The – Free iron oxides (Fed) were extracted using dithionite- degree of weathering and formation of pedogenic iron oxides citrate-bicarbonate method according to Mehra-Jackson and hydroxides is expressed by the ratio of Fed/Fet. An increas- (Mehra and Jackson 1960) ing Fed/Fet ratio reflects the progressive weathering of Fe- – Amorphous iron oxides (Feo) after ammonium oxalate bearing minerals with time (Arduino et al. 1986). extraction according to Tamm (Schlichting and Blume Soils formed from glacial deposits often show genetic het- 1962) with the ASA method (using the Philips 9100PU erogeneity and lithological discontinuity (Birkeland 1999; apparatus) Kühn 2001). Defining the relationship between lithogenesis and pedogenesis is one of the key problems on studying those The total content of zirconium in the soil samples was deter- soils. Evaluating the soil-formation pattern and the origin of mined by the fusion of soil with potassium pyrosulphate, and its soils based on the chemical composition of the soil mass re- concentration in the solutions was determined with the spectro- quires reference to soil parent materials. fluorimeter Hitachi F-2000 according to Wang et al. (2000). The aim of the present study was to determine the effect of For the characterization of lithogenic and pedogenic pro- lithogenesis and pedogenesis on the formation of Luvisols cesses in the soils, the following indices were calculated: from Vistula glaciation sediments on the base of profile distri- bution of iron compounds, particularly iron oxides and hy- – Weathering index (Fed/Fet) droxides in relation to texture, the content of hardly weathered – Iron activity index (Feo/Fed) mineral-zircon, clay mineralogy and the physicochemical – Crystalline iron content (Fec=Fed−Feo) properties of soils. Micromorphology study was done on undisturbed soil samples collected from the selected horizons of the studied 2 Material and methods profiles. The micromorphological features were described ac- cording to Fitzpatrick (1984). The thin sections were The soil profiles selected for the study are located in the area interpreted using the nomenclature of Stoops (2003). of the South Pomerania Lake District on the flat bottom- The clay mineralogy was estimated by X-ray diffraction anal- moraine plains formed during the Vistula stadial, the Poznań ysis of the clay fraction (<2 μm) separated by centrifugation on 398 J Soils Sediments (2016) 16:396–404 Fig. 1 Research area parallel (oriented specimens), Mg (saturated), Mg (satu- 3 Results and discussion rated and ethylene glycol solvated), K (saturated) and K (saturated after heating at 550 °C). Analyses were per- The soils were classified as Haplic Luvisols (IUSS Working formed on X-Pert Powder instrument, with Cuk α radi- Group WRB 2007). The following genetic horizons were ationat30mA,40kV. identified: Ap-Et-Bt-C. The feature differentiating the soils Statistical evaluation of results was performed using is the variation in thickness of diagnostic horizons: Et Statistica 10 software by setting Pearson’s linear correlation and Bt, across the profiles, which suggests a varied coefficients.