Loess deposits are recorders of aeolian activity during past glaciations. Since the size distribution of loess deposits\ud depends on distance to the dust source, and environmental conditions at the source, during transport, and at deposition,\ud loess particle size distributions and derived statistical measures are widely used proxies in Quaternary\ud paleoenvironmental studies. However, the interpretation of these proxies often only considers dust transport\ud processes. To move beyond such overly simplistic proxy interpretations, and toward proxy interpretations that\ud consider the range of environmental processes that determine loess particle size distribution variations we provide\ud a comprehensive review on the physics of dust particle mobilization and deposition. Furthermore, using\ud high-resolution bulk loess and quartz grain size datasets from a last glacial/interglacial sequence, we show\ud that, because grain size distributions are affected by multiple, often stochastic processes, changes in these distributions\ud over time allow multiple interpretations for the driving processes. Consequently, simplistic interpretations\ud of proxy variations in terms of only one factor (e.g. wind speed) are likely to be inaccurate. Nonetheless\ud using loess proxies to understand temporal changes in the dust cycle and environmental parameters requires\ud (i) a careful site selection, to minimize the effects of topography and source distance, and (ii) the joint use of\ud bulk and quartz grain size proxies, together with high resolution mass accumulation rate calculations if possible

Centennial-scale mineral dust peaks in last glacial Greenland ice cores match the timing of lowest Greenland temperatures, yet little is known of equivalent changes in dust-emitting regions, limiting our understanding of dust−climate interaction. Here, we present the most detailed and precise age model for European loess dust deposits to date, based on 125 accelerator mass spectrometry ¹⁴C ages from Dunaszekcső, Hungary. The record shows that variations in glacial dust deposition variability on centennial–millennial timescales in east central Europe and Greenland were synchronous within uncertainty. We suggest that precipitation and atmospheric circulation changes were likely the major influences on European glacial dust activity and propose that European dust emissions were modulated by dominant phases of the North Atlantic Oscillation, which had a major influence on vegetation and local climate of European dust source regions. Significance Atmospheric dust is a major component of climate change. However, the relationship between glacial continental dust activity and abrupt centennial–millennial-scale climate changes of the North Atlantic is poorly known. Recent advances in high-precision radiocarbon dating of small gastropods in continental loess deposits provide an opportunity to gain unprecedented insights into dust variations and its major drivers at centennial–millennial scales from a near-source dust archive. Here, we show that Late Quaternary North Atlantic temperature and dustiness in Greenland and Europe were largely synchronous and suggest that this coupling was driven via precipitation changes and large-scale atmospheric circulation.

The Paks loess-paleosol sequence is one of the most important terrestrial records of Middle and Late Pleistocene environmental changes in East Central Europe, spanning the last ca. 0.8 Ma. While geochemical proxies demonstrate a general decreasing chemical weathering trend over the last 0.8 Ma in the Carpathian Basin, mineralogy and derived indices reflect intensifying physical erosion. In theory, the observed chemical weathering trend can be accounted for both by enhanced input of relatively unweathered material and by climate deterioration during the Quaternary, as the used proxies like CIA are not capable of distinguishing between pre- and post-depositional weathering. Enhanced physical erosion of the source areas, driven by tectonism, and resulting increased sedimentation of fresh mineral dust at the depositional site are demonstrated by increasing dolomite, illite and chlorite contents and sme/ill, sme/(ill+chl) ratios from older to younger sediments in the profile, together with increasing thickness of loess layers towards the youngest part of the sequence. At the same time, constant smectite contents (30-40%) in paleosols appear to disprove progressive aridization of interglacials through time and suggest that the duration of pedogenesis played an important role in determining soil types. Further, the increasing proportion of inherited phyllosilicates (illite and chlorite) would, in theory, raise the possibility that the decreasing values of chemical weathering indices are just artifacts of enhanced physical erosion and resulting increased dust deposition by a dilution effect. The above findings highlight the fact that our general view on chemical weathering is oversimplistic, as its ’equation’ includes two basic variables, tectonism and time beyond climate and the interplay of these equally important factors will eventually determine its final value. To get a better grasp of these processes one needs further data (more age control in loess profiles, data on uplift in and around sedimentary basins) and more sophisticated proxies, as the mineralogical data presented here can be considered only semi-quantitative.\ud Regarding the provenance of sediments in the Paks profile, geochemical data demonstrate that felsic rocks dominated the source areas and there have been only very little variations in provenance over the last ca. 0.8 Ma. Significant contributions from mafic/ultramafic rocks to the sediments can be ruled out as revealed by lower abundances of ferromagnesian trace elements. The appearance of amphiboles and high dolomite contents suggest that loess material was at least partly sourced from local rocks and geochemical data reveal a genetic link between floodplain sediments and loess deposits.\u