Periodicities of paleoclimate variations in the first high-resolution non-orbitally tuned grain size record of the past 1 Ma from SW Hungary and regional, global correlations

Abstract

This paper presents the results of grain-size analyses of an independently-dated loess/paleosol record dating back ca. 1 Ma from SW Hungary. The record follows an upward coarsening trend with a clear prevalence of coarse silts and fine sands. Variations are mainly controlled by fluctuations in sand input highlighting iterative changes in dust aerodynamics over the past 1 Ma in the source region found 50-100 km NW of our site. Based on our results regional factors influenced the intensity and nature of dust accumulation. Contrasting trends with the Chinese Loess Plateau in certain periods reflect a greater importance of the Atlantic region driving the evolution of nearby continental ice sheets. Proximity and expansion of these had significant impact on local wind field. Low topography of the surrounding mountain belts allowed for the intrusion of stronger cold winds, higher abrasion in the source region and transportation of coarser particles to the site from 700 to 450 ka. Another marked upward increase in grain-size from 400 ka can be linked to increasing continentality which along with tectonic activity resulted in a drop in the groundwater table in the source region and intensified erosion of formerly relatively stable surfaces bringing more coarse material to our site.

Magnetostratigraphy and magnetic susceptibility of the best developed Pleistocene loess-palaeosol sequences of Ukraine: implications for correlation and proposed chronostratigraphic models

“…For strati graphic equiv a lents of palaeogeographic stages we have adopted a des ig na tion in the sys tem of Markoviae et al (2011Markoviae et al ( , 2015 by add ing the pre fix U indi cat ing Ukrai nian loess stra tig ra phy. A com par i son of magnetic sus cep ti bil ity, palaeomagnetic re sults (our data and ma teri als of Tretyak and Vigilyanskaya, 1994), cli ma tic con di tions (Veklich, 1982(Veklich, , 1987Lisiecki and Raymo, 2005;Matviishyna et al, 2010;Gozhik and Gerasimenko, 2011;Fitzsimmons et al, 2012;Head and Gibbard, 2015;Obreht et al, 2016;Sirenko, 2017Sirenko, , 2019Sümegi et al, 2019), palaeopedological prop er ties (Veklich, 1968;Sirenko and Turlo, 1986;Markoviae et al, 2012;Sümegi et al, 2018 and oth ers), as well as anal y sis of ac cu mula tion rates, has led us to the fol low ing in ter pre ta tion.…”

Environmental changes in southeastern Europe over the last 450 ka: Magnetic and pedologic study of a loess-paleosol profile from Kaolinovo (Bulgaria)

“…The persistence of consistently high CSI values within S 1 paleosol and L 1 loess suggests an increased wind intensity and severe glacial conditions during mid to late MIS 6 and MIS 4. Similar pattern was observed in other loess e paleosol records from Central and Europe (Fitzsimons et al, 2012;Sümegi et al, 2020), from the Ioannina basin, NW Greece, over MIS 6 (Wilson et al, 2021) or in Lake Ohrid record (e.g. Francke et al, 2016).…”

“…The mean value (22.7 10 À8 m 3 kg À1 ) observed within the upper part of the unit (380e420 cm) is the lowest in the studied sequence, suggesting low weathering of aeolian dust during the Penultimate glacial (MIS 6). Similar results, pointing to increasing wind intensity towards mid to late MIS 6 are reported by Sümegi et al (2020) for Udvari core (SW Hungary), suggesting that this is a common feature on a regional scale. Stronger westerly winds associated with lower temperatures and reduced rainfall in the region could be induced by a southward migration of the winter polar front during glacial (or stadial) periods as already pointed out from Black Sea sediments (Wegwerth et al, 2016).…”

Significance of the Ukrainian loess-palaeosol sequences for Pleistocene climate reconstructions: rock magnetic, palaeosol and pollen proxies

“…Despite of significant amount of data obtained by Quaternary geology and palaeogeography, the forecasts of future climate change differ significantly. Therefore, nowadays a great attention is paid to implementation of new research methods within a multidisciplinary approach, to the search of new complete sections within the terrestrial archives, and to analysis of the factors that have caused palaeoenvironmetal changes [Vandenberghe, Nugteren, 2001;Buggle et al, 2013;Sümegi et al, 2015Sümegi et al, , 2019Marković et al, 2018;Zeeden et al, 2018;Chmielowska, Woronko, 2019;Molnár et al, 2021;Scheidt et al, 2021;Wacha et al, 2021].…”