Naslov

Morphological, Chemical and mineralogical properties of pseudogley on loess along a precipitation gradient in the Pannonian region of Croatia
(Morphological, Chemical and mineralogical properties of pseudogley on loess along a precipitation gradient in the Pannonian region of Croatia)

Autori

Durn, Goran, Rubinić, V. ; Husnjak, Stjepan, Tadej, Neven

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

Izvornik
Book of Abstracts / Marjanac, Ljerka - , 2013

Skup
3rd Scientific Meeting on Quaternary Geology in Croatia

Mjesto i datum
Zagreb, Hrvatska, 21.03.2013. - 22.03.2013

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
morphological; chemical; mineralogical; properties; pseudogley; loess; Pannonian; region; Croatia

Sažetak
We sampled theree pseudogleys developed on loess across a zon of 300 mm mean annual precipitation (MAP) gradient in the Pannonian region of Croatia in order to determine their morphological, Chemical and mineralogical properties and to evaluate the degree to which climate influenced their genesis. Soil profiles 1, 2 and 3 were opened within MAP zones of 900-1000, 800-900 and 700-800 mm, respectively. The same provenance of pedogenetically modified loess parent material was confirmed by the almost identical La/Ce and Sm/Nd ratios of C horizons in all three profiles. In all three profiles clear redoximorfic reatures (RMF) were observed from A horizons downwards. Generally, the aboundancy of RMF was highest in Btg and Cg horizons, in whic highest Fe d values were also observed. Substantial morphological (A and Eg horizons thicknesses and colors, Btg horizons stagnic color patterns) and Chemical (pH, base saturation, topsoil organic C content) properties of the investigated profiles are consistent with the precipitation gradient. On the other hand, vertical distribution of clay size fraction along soil profiles appears to be a function of actual soil pH, rather than MAP. Nevertheless, we consider clay illuviation to have been the main process in creationo of vertical texture contrast between the eluvial and illuvial soil horizons of all investigated profiles. This is supported with illuvial nature of accumulated clay observed in thin sections, as well as with Chemical Indeks of Alteration (CIA) and Ti/Al ratio distributions along analyzed soil profiles. Significant differences in clay minerals distribution among investigated profiles were observed. While he content of illitic material, kaolinite and NN mixed-layer clay mineral is fairly constant with depth in all profiles, distributions of chlorite, smectite, vermiculite and chlorite-vermiculite mixed layer mineral (C-V MLM) vary among analyzed profiles. We consider that chlorite, illitic material, kaolinite and probably smectite are inherited from parent material, while C-V MLM and vermiculite are formed as a result of chlorite destabilization. C-V MLM, an intermediate mineral phase during the process of vermiculization, is most stable in profile 3 with the lowest MAP. Its complete transformation to vermiculite in profile 1 can probably be attributed to the low pH of the profile 1 compared to profiles 2 and 3. We conclude that, due to partial heterogeneity of loess parent material, investigations and interpretations of pseudogley climosequences in the Pannonian region of Croata need to be approached with caution.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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