Naslov
Adsorption properties of loess and overlying topsoil of the continental loess sections in northwestern Croatia

Autori
Tomašić, Nenad ; Lučić, Mavro ; Vučetić, Tajana ; Kampić, Štefica ; Juranović Cindrić, Iva ; Pikelj, Kristina

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstracts, 6th Mid-European Clay Conference (MECC'12) / Štasny, Martin ; Žigova, Anna - Průhonice : Czech National Clay Group, 2012, 145-145

Skup
6th Mid-European Clay Conference (MECC'12)

Mjesto i datum
Průhonice, Češka Republika, 04.09.2012. - 09.09.2012

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
loess ; soil ; clay ; CEC

Sažetak
Four loess sections situated in northwestern Croatia (Gušćerovec, Rovišće, Ludina and Kloštar Ivanić), approximately 10 m in depth, were investigated for their adsorption properties. In each section the samples were collected at three horizons: topsoil excluding the uppermost 15 cm, intermediate zone (soil- loess transition) being 40-50 cm in depth, and loess horizon at various depths. A change in bulk mineralogical composition, iron and manganese oxyhydroxides and organic matter content was monitored and compared to a change in cation exchange capacity throughout the investigated sections. Granulometric analysis of the loess samples showed that the silt fraction predominated ranging 55-75%. Clay fraction ranged between 24-43%. The sediment can be classified as very fine grained silt. Bulk mineral composition was determined by X- ray diffraction, and clay minerals were mutually differentiated upon saturation with ethylene glycol, and heating at 400 and 550°C. Content of iron and manganese oxyhydroxides was determined by oxalate method (in darkness), and that of organic matter by heating at 375 °C overnight. Cation exchange capacity (CEC) was determined by copper ethylenediamine complex at pH 7. Mineral composition of topsoil, intermediate zone and loess comprises quartz and illite-muscovite as main constituents with subordinate plagioclase, chlorite, kaolinite and, in some cases, vermiculite. In the investigated profiles the mineral composition does not vary significantly with only illite- muscovite being slightly more abundant in loess than in topsoil. Iron and manganese oxyhydroxides, with iron compounds being more abundant (1.12-7.02% Fe2O3), decrease with depth. Their higher content in topsoil can be related to mineral weathering and pedogenesis. Organic matter content changes irregularly through the sections. CEC values range from 7 to 21 mEq/100 g, and generally increase with depth. Topsoil CEC values range 7-11 mEq/100 g, those in intermediate zone 8-14 mEq/100 g and in loess 14-21 mEq/100 g. The observed trends of CEC value distribution throughout the investigated loess sections indicate its predominant relation to the phyllosilicate content, especially illite-muscovite. Also, the CEC values correspond well to the mean CEC values of phyllosilicate minerals determined in both topsoil and loess horizons.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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