Late Pleistocene Paleosol Formation in a Dynamic Aggradational Microenvironment - a Case Study from the Mala´ Nad Hronom Loess Succession (Slovakia)
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Catena 199 (2021) 105087 Contents lists available at ScienceDirect Catena journal homepage: www.elsevier.com/locate/catena Late Pleistocene paleosol formation in a dynamic aggradational microenvironment - A case study from the Mala´ nad Hronom loess succession (Slovakia) a,* b ´ b,c d ˇ e f B. Brada´k , D. Csonka , A. Novothny , J. Szeber´enyi , A. Medvedova´ , P. Rostinsky , K. Feh´er g, G. Barta b, T. V´egh b, K. Kiss b, M. Megyeri b a Department of Physics, University of Burgos, Av. de Cantabria, s/n 09006, Burgos, Spain b ELTE Eo¨tvo¨s Lora´nd University, Institute of Geography and Earth Sciences, Department of Physical Geography, Pa´zma´ny P´eter s´eta´ny 1/C. H-1117, Budapest, Hungary c Leibniz Institute for Applied Geophysics (LIAG), Stilleweg 2, 30655 Hannover, Germany d Geographical Institute, Research Centre for Astronomy and Earth Sciences, 45 Budao¨rsi út, H-1112 Budapest, Hungary e University of Matej Bel Faculty of Natural Sciences, Banska´ Bystrica, Tajovsk´eho 40, 974 01, Slovak Republic f The Czech Academy of Sciences, Institute of Geonics, Department of Environmental Geography, Drobn´eho 28, 60200 Brno, Czech Republic g ELTE Eo¨tvo¨s Lora´nd University, Institute of Geography and Earth Sciences, Department of Environmental and Landscape Geography, Pa´zma´ny P´eter s´eta´ny 1/C, H- 1117 Budapest, Hungary A R T I C L E I N F O A B S T R A C T Keywords: The geomorphological characteristics of the loess succession at Mala´ nad Hronom (Slovakia) mean that it pro- Sedimentation vides a valuable opportunity for the investigation of differences in soil formation in various topographic posi- Pedogenesis tions. Along with the semiquantitative characterization of the paleosols (on the basis of physical properties, Paleogeomorphology texture, the characteristics of peds, clay films, horizon boundaries), high-resolution field magnetic susceptibility Multiproxy measurements and sampling were carried out along four different sections of the profile. Samples for lumines- Heatmap Principal component analysis cence dating were also taken, in order to establish the chronostratigraphical position of the paleosols studied. The comparison of various proxies revealed the differences in soil formation in a dynamic aggradational microenvironment for the same paleosol horizons located in various positions along the slope. Contrary to expectation, paleosols developed in local top or slope topographical positions did not display significant dif- ferences in e.g. in their degree of development, nor the characteristics of their magnetic susceptibility curves. In the case of paleosols in positions lower down the slope, signs of quasi-permanent sediment input could be recognized as being present as early as during the formation of the soil itself. This sediment input would seem to be surpassed in the case of pedogenesis strengthened by the climate of the last interglacial (marine isotope stage - MIS 5). Pedogenesis seems to be sustained by renewed intense dust accumulation in the Late Pleistocene, in MIS 3, though compared to MIS 5, the climate of MIS 3 did not favor intense pedogenesis. Despite the general belief that loess series formed in plateau positions can preserve terrestrial records without significant erosion, in the case of the Mala´ nad Hronom loess this is not so. Compared to the sequence affected by erosional events in the local top position, the sequence affected by quasi-continuous sediment input in the lower slope position seems to have preserved the soil horizons intact. 1. Introduction paleosol–landscape associations; and paleosols are also helpful in the reconstruction of paleoclimate (Kraus, 1999). There are many applications of paleosol horizons in geology. For On the local scale, lateral changes in the characteristics of paleosols example, paleosols can be used in stratigraphic studies as marker hori- formed on clastic sediments reflect the grain size of the parent material zons for the local and regional correlations; they can be used to interpret and, indirectly, the geomorphology (topography). At the regional level – and reconstruct paleogeomorphology via the analysis of so, say, in the case of a sedimentary basin – paleosol properties reflect * Corresponding author. E-mail address: [email protected] (B. Brada´k). https://doi.org/10.1016/j.catena.2020.105087 Received 12 June 2020; Received in revised form 23 November 2020; Accepted 28 November 2020 Available online 19 December 2020 0341-8162/© 2020 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). B. Bradak´ et al. Catena 199 (2021) 105087 local differences in clastic sedimentary characteristics (grain size), succession verified that the soil horizons represent the same warm, topography, climate and subsidence/accumulation rates (Kraus, 1999). humid period, namely, the MIS 5 interglacial; this, in turn, provided a A vast amount of knowledge concerning paleosol horizons and their unique opportunity for the comparison of the characteristics of pedo- significancein the reconstruction of interglacial climate is available – for genesis from the same paleoclimatic period, but in different paleo- useful summaries of paleosols in loess, see e.g. in Muhs and Bettis (2003) geomorphic positions. and Mush (2007a, b). Here the focus is on those studies, considerably Ghafarpour et al. (2016) studied the Mobarakabad and Aghband fewer in number, which go beyond this, attempting to map the influence loess (Iran). In the Mobarakabad succession “the pedocomplex sequence of paleogeomorphological variation and the differences in sedimenta- splits into fivedifferent paleosols that are intercalated in the loess with tion rate (i.e. the local variation of paleosol horizons) in the develop- anticlinal shapes” (Ghafarpour et al., 2016, p. 97). The relation of ment of what are considered to be the same paleosol units in loess- paleosol horizons may suggest the influence of tectonic activity (e.g. paleosol sequences. Machette, 1978), but since no tectonic activity is to be expected in the Although most studies of loess-paleosol sequences focus on so-called area (Ghafarpour et al., 2016, referring to Kehl et al., 2005), the anti- plateau loess (e.g. Markovi´c et al., 2015), in which the likelihood of clinal shape of the loess-paleosol sequence was interpreted as the result erosional hiatuses and redeposition is minimal, research revealing the of the mantling of a pre-existing land surface (Ghafarpour et al., 2016). potential of non-plateau loess in complex environment reconstructions The influence of tectonic processes may well require reconsideration does exist – it should be noted that here, ‘non-plateau’ refers to any type following the study by Motavalli-Anbaran et al. (2011), which suggests of loess succession formed in non-plateau paleotopographical position, tectonic activity in the region (in the Alborz Mountains): as indicated by such as Veroce,¨ H´evízgyork,¨ and Sütto} (see below). various (magnetic) proxies, the different slope position in the Iranian On the basis of the characterization of a loess-paleosol sequence successions in those studies might cause different levels of exposure to formed on a paleoslope, Bradak´ et al. (2011) and Bradak-Hayashi´ et al. climatic components (e.g. precipitation) during the forming of paleosols (2016) were able to describe complete climate cycles. The model pre- (Ghafarpour et al., 2016). In a precursor to the Iranian loess studies, Kehl sented involved redeposited loess horizons as a marker of the transition et al. (2005) had studied and characterized paleosols and soil forming environment between pedogenic (interglacial) and sedimentary environments in the Basin of Persepolis via the study of sequences (glacial) phases. The studies also used the redeposited loess to charac- consisting of loess, loess-like sediments (redeposited loess) and paleosol terize the paleoenvironment of such transition periods. horizons in various stages of development. One of the most complex studies of loess profilesinfluenced by slope The above examples show how variable the characteristic of the processes was conducted on the Late Pleistocene Krems-Wachtberg development of a loess succession in a non-plateau position can be. succession (e.g. Handel¨ et al., 2009a, b; Hambach, 2010; Terhorst Although the application of such successions as a key profile in strati- et al., 2014). The Krems-Wachtberg loess succession is famous for a graphic correlation can be called into question due to the possible hia- complex formation influencedin particular but not exclusively by slope tuses (Markovi´c et al., 2015), they may play a significant role in the processes: besides the dominant aeolian activity and stable and short description of paleoenvironments. Along with various methods (e.g. periods of pedogenesis, erosional processes contributed to the forming of micromorphology), the study of the relationship between sedimentation the sequence, while in the course of the reduced phases of aeolian and pedogenesis may provide essential information about the environ- sedimentation, the formation of Cryosols and permafrost processes ment in which the soil was formed. Due to the paleotopographical became dominant. What is more, some parts of the sequence were characteristics of the Mala´ nad Hronom loess profile (a succession affected by solifluctionand erosional processes on slope (for a summary, developed on a paleoslope; Szeberenyi´ et al., 2020), the study of pale-