Palaeolithic tools preserved in the loess-palaeosol sections of southern Tajikistan as early as ~800 ka evidence the episodic presence of ancient hominins across major Quaternary climate shifts, such as the Mid-Pleistocene and Mid-Brunhes Transitions (MBT). The richest assemblage of lithic tools found in the region, the Karatau Culture, is found mainly in palaeosols associated with Marine Isotope Stages (MIS) 15, 13, and 11, with intervening glacial periods as well as previous and subsequent interglacial periods characterised by a near absence of tools, except for MIS 14 which contains a smaller number of artefacts. Curiously, the disappearance of the Karatau culture coincides with an abrupt increase in magnetic susceptibility in the palaeosol units. Currently, the cause of the alternating phases of occupation and their possible connection to wider-scale climate remain unclear.The Khovaling Loess Plateau loess-palaeosol sequences provide an opportunity to understand the climatic and environmental context of the appearance and disappearance of early hominins. Since the Khovaling Loess Plateau is located in a transitional zone between climate systems (Mid-Latitude Westerlies, Siberian High and Indian Monsoon) regional climate may be sensitive to global climate reorganisations within the Quaternary. Based on the observed abrupt increase in magnetic susceptibility following MIS 11, it has been hypothesized that monsoon incursions may have occurred during some interglacials, and that these incursions may have ceased after MIS 11, coinciding with the disappearance of the Karatau culture. However, evidence for potential monsoon incursions is highly debated, and the cause for the change in the magnetic susceptibility record remains unclear. In this study, we apply a novel multi-frequency magnetic susceptibility approach, complemented by elemental composition data from XRF and XRD, and by paleoclimate simulations, to investigate possible variations of the hydroclimate in Central Asia. The simulations, performed with the fully-coupled HadCM3 global climate model, allow us to assess the relative and combined effects of orbital, greenhouse gas and ice sheet forcings on the hydroclimate variability including possible moisture transport pathway changes in Central Asia around MIS 13 and 11.Based on the combined evidence, we argue that the abrupt increase in bulk magnetic susceptibility after MIS 11, observed across different sites in southern Tajikistan, is best explained by a sediment provenance change. It appears to be unrelated to any change in rainfall seasonality, and to a lesser degree, intensity. We demonstrate that relative frequency dependence of magnetic susceptibility (χFD %) is the most suitable proxy for calculating quantitative palaeoprecipitation estimates in this region. Our magnetic susceptibility results, calibrated against a modern-analogue based transfer function, indicate that the demise of the Karatau culture coincides with an approximate +25% increase in regional annual mean precipitation. Combined with the other proxy data, this result indicates a relatively stable regional climate across periods of hominin occupation and the MBT.

The Gravettian site of Bodrogkereszt & uacute;r-Henye in northeastern Hungary has long been considered the oldest of its kind in the region. Fieldwork in 2019 revealed a stratigraphic succession spanning from the Late Aurignacian to the Late Gravettian. The Late Aurignacian component is represented by few artefacts and lacks archaeozoological remains, suggesting a short-term occupation, whereas the Late Gravettian yielded an abundant archaeological record indicative of a base camp within a highly mobile settlement system connected to Eastern Central (ECE) and Eastern Europe. The Late Aurignacian corresponds to a climatically milder phase, while the Late Gravettian is associated with colder conditions. The sequence is incomplete, lacking Early Gravettian and Pavlovian layers, comparable to Early-Middle Upper Palaeolithic sequences in Poland, Slovakia, and Hungary. These data suggest that the Early Gravettian in western ECE was contemporaneous with the Late Aurignacian in eastern ECE, and that eastern ECE experienced a brief human occupation hiatus during the Pavlovian. The Late Gravettian represents the Middle Upper Palaeolithic cultural that spread across Eastern Central and Eastern Europe with the onset of colder conditions at the MIS 3-2 transition, likely reflecting adaptive strategies to cold environments, including long-distance human mobility.

Abstract Central Asia represents a key region for our understanding of early human dispersal patterns, because it served as a migration corridor that linked the Levant and southern Caucasus with Northeast Asia. However, no Early Palaeolithic sites in Central Asia are anchored with reliable age constraints, including the thick loess-palaeosol sections in Tajikistan that recorded early human activities and environmental changes over multiple glacial-interglacial cycles. This lack of absolute age constraints is presently a key factor limiting our understanding of the early human occupation history of this region. Here, we provide a comprehensive description and an absolute chronological framework for the Early Palaeolithic Karatau Culture; defined by the rich lithic assemblages found in palaeosols in the Khovaling Loess Plateau, Tajikistan. Age constraints are provided through multi-method analysis of three loess-palaeosol sections in the Khovaling Loess Plateau, combining luminescence ages, cosmogenic 26 Al- 10 Be concentrations, and magnetostratigraphic boundaries into a probabilistic inverse age-depth model. This model shows that the Karatau Culture flourished with the onset of Marine Isotope Stage 15, thrived during Marine Isotope Stage 13 and 11, but disappeared around onset of Marine Isotope Stage 10. We frame the archaeological occupations within local and regional ecological settings to better understand the drivers of Pleistocene human migrations in Central Asia.

Quantitative reconstruction of temperature remains the major focus and challenge of paleoclimate research, especially in the terrestrial realm. This study is aimed at testing the usefulness of Δ47 of earthworm’s biospheroids (EBS) as a temperature proxy by comparing the EBS-derived T47 values to those obtained from previously studied land snails. For this purpose, the Dunaszekcső loess record in southern Hungary has been selected, which is an extensively studied section with a high resolution 14C chronology [1,2,3], revealing stadial-interstadial variations in sedimentation rates.Sixteen samples were collected in 10 cm resolution from the loess layers between 850-770 cm and 695-615 cm representing the GI-5.1 (30.6-30.8 ka) and GI-3.1 (27.5-27.8 ka) periods and surrounding stadials [4]. The associated temperature was calculated previously between 8-15 °C [4] based on the clumped isotope compositions of mollusc shells of these layers.The impact of sample preparation methods on Δ47 values of secondary carbonates is unknown and is a potential concern. To test this, two different sample preparation methods were applied on Trochulus hispidus shells recovered from the mentioned loess layers: 1) treatment in 1 m/m% HCl solution and 2) treatment with 3 m/m% H2O2 solution under vacuum and in ultrasonic bath in ultrapure water. The reconstructed temperatures based on the Δ47 values of the snail shells typically fell between 7-15 °C (HCl pretreatment) and 9-14 °C (H2O2 pretreatment), in very good agreement with previous published land snail T47 data [4]. The average temperatures obtained from biospheroids reveal the same stadial-interstadial temperature pattern previously reconstructed by molluscs. The mean T47 values of the two pretreatment methods are within the expected temperature range derived from the snail shells.Clumped isotope analysis was also performed on biospheroid samples from the same layers, and the calculated temperatures were compared with those obtained from snail shells by Újvári et al. [4]. To demonstrate that the biospheroid carbonates from the same layers are of the same age as the examined molluscs, we performed radiocarbon dating on the biospheroids. Our primary goal is to investigate whether the Δ47 compositions are affected by the so-called vital effect and to what extent the formation of biospheroid carbonates is influenced by these kinetic effects. To achieve this goal, a long-term experiment is going on. We perform climate chamber experiments [5,6,7] at temperatures of 8, 11 and 15 °C. Other variables, including relative humidity, CO2 concentrations and the stable isotope compositions of diet and spray liquid are also controlled. The first results will be presented. References:[1] Újvári, G. et al. 2014, Quaternary Science Review Vol. 106, 140-154[2] Újvári, G. et al. 2016, Quaternary Geochronology Vol. 35, 43-53[3] Újvári, G. et al. 2019, Palaeogeography, Palaeoclimatology, Palaeoecology Vol. 518, 72–81[4] Újvári, G. et al. 2021, AGU, Advancing Earth and Space Science, Paleoceanography and Paleoclimatology, Volume 36, Issue 8[5] Canti, M.G. 2009, Soil Biology & Biochemistry Vol. 41, 2588-2592[6] Lambkin, D.C. et al. 2011, Applied Geochemistry Vol. 26, S64-S66[7] Versteegh, E.A.A et al. 2014, Soil Biology and Biochemistry Vol. 70, 159-

The loess-paleosol sequences of Khovaling, southern Tajikistan preserve signatures of prehistoric human settlement during the Early Paleolithic. Archaeological finds excavated from Early Paleolithic sites located adjacent to the Obi-Mazar River indicate this part of Central Asia served as an early hominin migration corridor between Africa and destinations further east. The region has been reinvestigated by the "Timing and ecology of the Human Occupation of Central Asia" (THOCA) project since 2021, and > 2000 lithic artifacts have been recovered in pedocomplexes (PCs) 4, 5, and 6 with ages spanning similar to 600-400 thousand years before present (ka). This is the first study to analyze novel biomarkers preserved in the loess-paleosol samples collected from on-site, near-site, and off-site contexts on the Khovaling Loess Plateau (KLP) to study early human occupation in Central Asia. Average chain length (ACL) of straight chain alkanes (n-alkanes) and wood/grass proxies reveal wetter climates with more trees during interglacial periods and drier climates with more grass vegetation during glacial periods. High abundances of total polycyclic aromatic hydrocarbons (PAHs) and high molecular weight PAHs (HMW PAHs) were also found during the interglacial periods of Marine Isotope Stages (MIS) 11, 13, and 15 suggesting landscape-scale fires occurred during similar to 600-400 ka. Based on our results in conjunction with lithic artifacts excavated from Early Paleolithic sites in Khovaling, Tajikistan, we suggest early hominin occupation and existence of pyrotechnology among early groups of hominins in this territory.

The Eocene period experienced several hyperthermal events with the Paleocene-Eocene Thermal Maximum being the most significant. During this event, global mean surface temperatures were 5-6 degrees C higher and latitudinal temperature gradients were reduced compared to the late Paleocene. Unlike marine temperature records, terrestrial archives are limited, posing challenges for testing climate model competence in simulating the magnitude and spatial patterns of temperature change under a high carbon dioxide climate. Here we analysed mudstone paleosols from the Tremp Group in Spain to reconstruct soil temperatures using carbonate nodules. Clumped isotopes revealed median calcification temperatures of 33.9 and 39.2 degrees C for the Late Paleocene and Paleocene-Eocene Thermal Maximum, respectively. The findings suggest a similar to 5 degrees C summer soil temperature increase during the Paleocene-Eocene Thermal Maximum. Continental proxy and model data indicate reduced (0.7-0.4 degrees C/degree) meridional temperature gradients between 25 and 75 degrees N latitudes, indicating more uniform heat distribution across latitudes than at present.

During the last glacial period (~118 to 11.7 ka), the Arctic has been characterized by a major redistribution of flora and fauna as a consequence of extreme climatic fluctuations, with associated glacial advances and retreats, sea-level changes, and shifting sea ice extent. In the high-latitude regions of Northern Europe that are currently subject to rapid climate warming, we lack a comprehensive understanding of faunal biodiversity in the last glacial period due to the extreme rarity of preserved organic remains. Here, we present a stratified sediment deposit with a diverse faunal composition preserved in a bone-bearing layer in Arne Qvamgrotta, part of the Storsteinhola cave system (68.10° N 16.38° E) in Northern Norway. Chronological analyses of sediments and bones including radiocarbon, optically stimulated luminescence, uranium-thorium, and phylogenetic dating place the faunal assemblage in Marine Isotope Stage 5a (MIS 5a, Odderade interstadial, ~85 to 71 ka). Combining comparative osteology and bulk-bone metabarcoding, we identify 46 taxa, including mammals, birds, and fish, with several species not previously found in Fennoscandia. The fauna implies a nonanalogous cold-adapted coastal community, with close proximity to sea ice and nearby freshwater bodies. Mitogenome analyses of a subset of taxa identify extinct lineages which attest to a lack of habitat tracking and the absence of a local refugium during the subsequent fully glaciated periods. This faunal record demonstrates long-term faunal dynamics and coastal environmental conditions during MIS 5a in the European Arctic.

Greenland ice cores demonstrate that transient last glacial cold climate events (stadials) were associated with greatly enhanced atmospheric dust loading. Detailed radiocarbon dating of loess in central Europe reveals concurrent increases in dust activity in dust-emitting regions. However, the causes of these changes in dust emission and the role of dust in rapid climate change remain unclear. We address this uncertainty through multi-proxy analysis of loess sources in Hungary. Our results demonstrate that loess particles were dominantly produced by subglacial grinding processes in the eastern Alps. These particles were released along with stadial Alpine Ice Sheet-driven meltwater pulses, turning major river systems into efficient dust sources for loess deposition in Europe. Concurrent strengthened anticyclonic circulation over northern Europe would have caused wider dispersal of Alpine Ice Sheet-derived dust as far as Greenland. Resultant continental-hemispheric scale changes in atmospheric dust loading likely amplified concomitant North Atlantic climate cooling and ice sheet decay during Greenland stadials.

Az észak-atlanti térség éghajlata meglehetősen változatos volt az utolsó eljegesedés során, ami a poláris jégmagok és mélytengeri üledékek proxy adatsoraiban igen jól dokumentált. Az általánosan hideg klímát hirtelen, néhány évtized alatt bekövetkező felmelegedési fázisok szakították meg, amelyek hosszabb, ezeréves időskálájú ciklusoknak voltak a részei. Ezek az úgynevezett Dansgaard–Oeschger (D–O) ciklusok sokszor igen hideg, Heinrich-stadiálisokban kulmináltak, ami intenzív jéghegyborjadzással járt a Labrador-félsziget körüli térségben. Ezek a gyors klímakilengések globális hatást gyakoroltak és érintették az eurázsiai kontinens éghajlatát is, valamint kihatottak a növényzetre és a kontinentális porkibocsátá­ra, amely direkt és indirekt visszacsatolásokon keresztül visszahatott a globális klímára. A közepes földrajzi szélességek (például Eurázsia) nagy területeit fedték be ebben az időszakban a szél által szállított por kiülepedéséből származó löszüledékek, amelyek unikális lehetőséget kínálnak a környezeti átalakulások és a porciklus változásainak együttes megismerésére a kontinenseken. Ezenfelül a szárazföldi porforrások és a poláris jégmagokba zárt ásványi por közötti kapcsolatok felderítése az északi félteke glaciális légkörzési mintázataiba enged bepillantást. Ebben a tanulmányban, amely az MTA doktori rövid értekezésem alapján született, két fő kutatási irányra koncentráltam: egyfelől arra, hogy a löszüledékek nagy pontosságú radiokarbon kormeghatározásával és újszerű, kvantitatív proxyk felhasználásával a korábbiaknál pontosabban érthessem meg a D–O események hatásait a Kárpát-medencében és tágabb értelemben Közép-Európában, és rávilágítsak az ezek mögött álló mechanizmusokra. Másfelől a NGRIP (North Greeland Ice Core Project) jégmag glaciális aeroszolmintáinak és az északi félteke különböző kontinentális porforrásrégióiból származó porminták felhasználásával, valamint agyagásványos, tradicionális (Sr-Nd) és új izotóp-geokémiai (Hf, δ2H) indikátorok segítségével világosabb képet szerettem volna kapni a fő porforrás(ok)ról.

Massive additions of 13C-depleted carbon to the atmosphere-ocean system at 55.9 Myr ago led to global warming of 5–8 °C, profound floral/faunal turnovers and alteration of the global hydrological cycle at the Paleocene-Eocene boundary. Climate and environmental changes over the late Paleocene and Paleocene-Eocene Thermal Maximum (PETM) are well-preserved in continental deposits, formed in the subtropical zone (paleolatitude ~35 °N), in the Tremp-Graus Basin, northern Spain. One of the key exposures is the Esplugafreda section, which is made up of ~250 m of red mudstones with abundant paleosols and contains numerous multi-episodic channel-like bodies of calcareous conglomerates and calcarenites. The paleosols contain abundant centimeter-sized soil nodules and gypsum indicating a semi-arid to arid paleoenvironment. The Paleocene-Eocene (P-E) boundary is located near the top of the continental section, based on a 6‰ negative carbon isotope excursion (CIE). The CIE spans more than 15–20 m of yellow cumulate paleosols formed during the Paleocene-Eocene Thermal Maximum (PETM). The post-PETM interval in the Esplugafreda section comprises 20 m of red paleosols rich in gypsum and characterized by normal soil nodule δ13C values.Here, we report the first carbonate clumped isotope thermometry data of selected soil carbonate bearing paleosol layers of the Esplugafreda sequence to quantify the magnitude of warming recorded in the sediments of this terrestrial subtropical site across the Paleocene-Eocene boundary. Soil nodules originated from red mudstone paleosols making up the upper part of the upper Paleocene Esplugafreda Formation and PETM yellow soils collected at two nearby sites. The nodules were sampled with a hand driller for Δ47 measurements, which were done using a Kiel IV carbonate device coupled to a Thermo Scientific 253 Plus IRMS at the Institute for Nuclear Research, Debrecen, Hungary. Stable carbon, oxygen isotope and clumped isotope compositions were calculated as the average of 8–16 replicate analyses of 100–150 μg of carbonate. The carbon and oxygen isotope ratios are reported in δ notation in per mil (‰) relative to the Vienna Pee Dee Belemnite (VPDB), while the temperature-dependent mass 47 anomaly on the I-CDES90°C scale. Temperatures were calculated using the Kele et al. (2015) calibration modified by Bernasconi et al. (2018) and the Anderson et al. (2021) calibrations.Soil carbonates of the Esplugafreda formation yield δ13Ccarb values between –8.55 and –5.85 ‰, while the PETM yellow soil carbonates are significantly more negative (–13.84 to –10.12 ‰), in good agreement with previous measurements. A much smaller, ~1.2 ‰ difference can be observed in the oxygen isotope compositions between these carbonates (δ18Ocarb: –5.46 to –4.13 versus –6.35 to –4.47 ‰). The Δ47-based paleotemperatures (T47carb) indicate mean soil carbonate formation of 33.8±9.5 °C during the late Paleocene, which are close to modern summer temperatures of subtropical regions. By contrast, a much higher mean temperature was recorded by soil carbonates of the PETM yellow soils (39±8.5 °C) with extreme (>40 °C) temperatures occurring 4 times more frequently than over the late Paleocene.This study was supported by the NKFIH through the OTKA K-137767 project.

Reconstructing source to sink relationships or the origin of sediments and sedimentary rocks is the main goal of sedimentary provenance analysis. Several processes alter the source signal during transport and deposition and the extraction of the initial provenance signal is usually realized by combination of multiple single grain methods determining mineralogy, chemical composition or radiometric ages. However, such methods are mostly applied to sand-sized sediments or sedimentary rocks, while finer grained material is usually analyzed by whole-rock geochemical means and seldom by single-grain methods. Considering the abundance of fine-grained sedimentary archives and that short lived climatic signals are frequently encoded in such archives (e.g. loess, varves, etc.), a strong need for single-grain, multi-method analyses of silt-sized sediments is obvious.Therefore, we developed a highly automated approach to modal mineralogy of silt-sized sediments and sedimentary rocks based on image segmentation and object detection capabilities of machine learning methods, which allows for correlative analysis (e.g. optical microscopy, Raman spectroscopy, SEM, EPMA, LA-ICP-MS) and increased sample throughput.To test if our approach is feasible for silt-sized sediments, we sampled three loess-paleosol-sequences (LPS) of similar age and from different loess domains. Based on heavy mineral compositional data and zircon U-Pb age distributions the LPSs can readily be differentiated, verifying the feasibility of our approach. Consequently, we hypothesize that this novel multi-method, high-throughput data acquisition within a highly automated workflow will allow for hitherto unprecedented spatial and temporal resolution as well as statistical significance of provenance information, potentially enabling new research pathways in sedimentary provenance analysis.

Central Asia represents a key region for our understanding of early human dispersal patterns, because it served as a migration corridor that linked the Levant and southern Caucasus with Northeast Asia. However, no Early Paleolithic sites in Central Asia are anchored with reliable age constraints, including the thick loess-paleosol sections in Tajikistan that recorded early human activities and environmental changes over multiple glacial-interglacial cycles. This lack of absolute age constraints is presently the key factor limiting our understanding of the early human dispersal history. Here, we provide a new comprehensive description and the first absolute age framework for the Early Paleolithic Karatau Culture; defined by the rich lithic assemblages found in paleosols in the Khovaling Loess Plateau (KLP), Tajikistan. Age constraints are provided through multi-method analysis of three loess-paleosol sections in the KLP, combining luminescence ages, cosmogenic 26 Al- 10 Be concentrations, and magnetostratigraphic boundaries into a probabilistic inverse age-depth model. This model shows that the Karatau Culture flourished with the onset of Marine Isotope Stage (MIS) 15, thrived during MIS 13 and 11, but disappeared around onset of MIS 10. We frame the archaeological occupations within local and regional ecological settings to better understand the drivers of Pleistocene human migrations.

The sulfur (S) isotope composition of ice cores represents a novel proxy to quantify variability in the sources of atmospheric sulfate. Sulfate aerosols exert a crucial but highly uncertain feedback on the climate system, acting as cloud condensation nuclei and scattering incoming solar radiation. Ice cores from Antarctica indicate that the majority of sulfate aerosols are sourced from marine biogenic activity, with little variability in emissions between glacial and interglacial periods. However, there are currently no published S isotope studies from the Arctic extending beyond the Common Era, and it is unclear how processes could differ between hemispheres. We present a high-resolution S isotope record of the NEEM ice core from Greenland, covering an entire glacial cycle from 0-128 ka BP. S isotope values appear to co-vary with the climate, exhibiting far lighter isotopic compositions during the Last Glacial compared to the Holocene or Last Interglacial. Systematic variability of S isotope values across Dansgaard–Oeschger events and strong linear relationships with water isotope compositions and calcium concentrations of the ice are also observed. We interpret these trends to show climatically controlled changes in the key sources of sulfate reaching the NEEM ice core site. During peak glacial conditions, the budget is dominated by sulfate sourced from terrestrial dust and volcanic emissions, with a negligible marine biogenic component. This finding suggests that we can use S isotopes to identify time periods when the source region for marine biogenic emissions reaching Greenland may have been completely ice-covered. Overall, this study provides new insights into the processes controlling sulfate aerosols in the Arctic and how the S cycle interacts with the climate.

Pleistocene loess records of the Khovaling Loess Plateau (KLP) in Tajikistan provide rich collections of lithic artifacts demonstrating past human presence in the region. To understand the timing of human activity and environmental conditions prevailing at that time U-Th dating and clumped/stable C/O isotope measurements have been applied to modern and Pleistocene soil carbonates (SCs) collected at several sites on the KLP and surroundings. U-Th ages were corrected by two methods: 1) assuming an initial [Th-230/Th-232] activity ratio of 0.85 +/- 0.25 based on gamma spectrometry of loess/paleosol samples, and 2) the isochron technique using leachates and fully dissolved subsamples. Diagenetic alteration and potential U/Th mobilization and related isotope fractionation due to alpha-recoil was also modelled and found to be minor in the studied soil carbonates. Compared to model ages as references, uncorrected 230 Th ages are only acceptable if measured [Th-230/Th-232] activity ratios of leachates are high (>30), while Th-230 ages derived using method 1 are mostly overcorrected. It appears that SCs can be reliably dated by the U-series disequilibrium method in this sedimentary setting, but isochron dating cannot be spared. Application of the isochron method is required to derive (230)Thmodel ages, which ensures that the non-zero initial (230) Th and possible U-Th gain/loss due to alpha-recoil can be simultaneously corrected and reliable U-Th ages obtained. U-Th ages of Pleistocene SCs clearly demonstrate postpedogenic ingrowth of multiple, non-contemporaneous populations of SCs within loess/paleosol units, and that SC formation happened in many cases under cold, presumably dry glacial climate conditions. Considering that U-Th ages of SCs provide minimum ages of the sediment in which they form, these ages can be useful in developing loess stratigraphic models and for correlation of paleosols with marine isotope stages. This implies that the age of a given paleosol and any lithic artifacts it may contain, indicating human activity, cannot be younger than the age of SCs formed in that paleosol. This is due to the nature of soil carbonates, which can be the product of both syn- and post-depositional processes. Clumped isotope thermometry of SCs collected from modern soils at three sites in Tajikistan provide evidence for SCs dominantly recording summer season soil temperatures, while the calculated soil water oxygen isotope signatures reflect annual signals and carbonate precipitation from source waters incorporating rainfall from prior to and during SC formation. In contrast, some Pleistocene SCs record soil temperatures and stable isotope compositions more appropriate to glacial conditions, confirming the findings of U-Th ages, and highlighting the primary role of aridity-driven soil moisture changes in SC precipitation in this setting. Considering the interpretative complexities of SC stable isotope compositions, involving issues such as SC formation depth within a soil/paleosol profile, seasonality of SC growth and violation of the law of superposition, SC stable isotope proxy records of past climates cannot be considered as a set of clearly sequential data through time. This implies that such SC-based stable isotope records must be accompanied by U-Th dating of carbonates to be meaningful.

Dansgaard-Oeschger (D-O) climate variability during the last glaciation was first evidenced in ice cores and marine sediments, and is also recorded in various terrestrial paleoclimate archives in Europe. The relative synchronicity across Greenland, the North Atlantic and Europe implies a tight and fast coupling between those regions, most probably effectuated by an atmospheric transmission mechanism. In this study, we investigated the atmospheric changes during Greenland interstadial (GI) and stadial (GS) phases based on regional climate model simulations using two specific periods, GI-10 and GS-9 both around 40 ka, as boundary conditions. Our simulations accurately capture the changes in temperature and precipitation as reconstructed by the available proxy data. Moreover, the simulations depict an intensified and southward shifted eddy-driven jet during the stadial period. Ultimately, this affects the near-surface circulation towards more southwesterly and cyclonic flow in western Europe during the stadial period, explaining much of the seasonal climate variability recorded by the proxy data, including oxygen isotopes, at the considered proxy sites.

Sediments of the Lena River represent an important environmental archive for understanding the Quaternary history of North-Eastern Siberia. However, at present, the structure, origin and age of the Lena River terraces are poorly known. This article presents results of lithofacies analysis and absolute dating of the Ust'-Buotama section exposing the fourth (Bestyakh) terrace of the Lena River. We report the first quartz and K-feldspar luminescence ages, the reliability of which was argued by age relations and standard tests. Three stratigraphic units have been recognized in the section (depths from the top): lacustrine-alluvial deposits (85-120 m) of the Mavrinka Formation; aeolian sand deposits of the Dolkuma Formation (23-85 m), and Holocene aeolian dune sediments (0-23 m). The resulting chronology suggests that the sediments of the Mavrinka Formation were deposited no later than 300 ka (MIS 9 or later). Deposition of the Dolkuma Formation occurred from -30 ka to -15 ka (late MIS 3 - late MIS 2). Holocene aeolian dune formed during initial Neoglacial cooling post climatic optimum (c. 5.5 cal ka BP). More extensive Late Holocene dune sediments which formed -400 years ago are coeval with Little Ice Age (11th-19th centuries).

Clumped isotope composition (Delta 47) of aragonitic shells of terrestrial molluscs allow the quantitative reconstructions of continental paleotemperatures from loess-paleosol records of the last 2.5 million years, but it needs testing the method under controlled laboratory conditions and using natural populations. In this study the stable carbon, oxygen and clumped isotope compositions of cultured individuals and field-collected specimens of three species (Clausilia pumila, Succinella oblonga and Trochulus hispidus), widespread in Quaternary loess deposits in Europe, were measured in the Debrecen (ATOMKI) and ETH Z & uuml;rich laboratories. Our data of cultured snails demonstrate that shells of the three species record Delta 47 signatures close to equilibrium conditions with mostly positive (C. pumila), both positive/negative (T. hispidus), and mostly negative (S. oblonga) offsets on the order of 0.0158 f 0.0105 parts per thousand (mean offsetf1 SD) compared to the Anderson et al. (2021) unified calibration. Calcification temperatures (T Delta 47) derived from C. pumila shells were found to be in excellent agreement with chamber temperatures of 12, 18 and 24 degrees C, especially in the ATOMKI laboratory (mean T offset: 2.1 f 2.2 degrees C, 1 SD), while the other two species exhibited larger discrepancies on the order of 5-8 degrees C (mean offset). Single shell-based mean T Delta 47 values of field-collected molluscs indicated growth temperatures spanning values from the frost-free period to summer season, or even above summer maxima. The sites of natural populations, characterized by different climate conditions, could be grouped using the aridity index (AI) with values of 0.96-1.06 representing mean temperature of the frost-free period (TFFP), and AI ranging either from 0.85 to 0.91 or 1.14 to 1.51 reflecting mean summer season or July temperatures (TJJA/TJ). Multi-shell T Delta 47, obtained by homogenizing the material of 3-5 shells of C. pumila and T. hispidus, reflect TJJA in most cases. We observed a dependence of the shell oxygen isotope compositions of the three species on oceanity/continentality with more negative/positive values characteristic for more continental/oceanic sites, likely due to moisture source distance and depletion of rainfall in 18O towards the continental interior. In addition, deviation of body fluid delta 18O values (derived from delta 18Oshell and Delta 47shell) from seasonal precipitation delta 18O is also controlled by an additional temperature effect, being independent of the climate zone of the collection site, but co-varying with the site-specific difference between single shell T Delta 47 and TJJA.

Massive additions of 13C-depleted carbon to the atmosphere-ocean system at 55.9 Myr ago led to global warming of 5–8 °C, profound floral/faunal turnovers and alteration of the global hydrological cycle at the Paleocene-Eocene boundary. Climate and environmental changes over the late Paleocene and Paleocene-Eocene Thermal Maximum (PETM) are well-preserved in continental deposits, formed in the subtropical zone (paleolatitude ~35 °N), in the Tremp-Graus Basin, northern Spain. One of the key exposures is the Esplugafreda section, which is made up of ~250 m of red mudstones with abundant paleosols and contains numerous multi-episodic channel-like bodies of calcareous conglomerates and calcarenites. The paleosols contain abundant centimeter-sized soil nodules and gypsum indicating a semi-arid to arid paleoenvironment. The Paleocene-Eocene (P-E) boundary is located near the top of the continental section, based on a 6‰ negative carbon isotope excursion (CIE). The CIE spans more than 15–20 m of yellow cumulate paleosols formed during the Paleocene-Eocene Thermal Maximum (PETM). The post-PETM interval in the Esplugafreda section comprises 20 m of red paleosols rich in gypsum and characterized by normal soil nodule δ13C values. Here, we report the first carbonate clumped isotope thermometry data of selected soil carbonate bearing paleosol layers of the Esplugafreda sequence to quantify the magnitude of warming recorded in the sediments of this terrestrial subtropical site across the Paleocene-Eocene boundary. Soil nodules originated from red mudstone paleosols making up the upper part of the upper Paleocene Esplugafreda Formation and PETM yellow soils collected at two nearby sites. The nodules were sampled with a hand driller for Δ47 measurements, which were done using a Kiel IV carbonate device coupled to a Thermo Scientific 253 Plus IRMS at the Institute for Nuclear Research, Debrecen, Hungary. Stable carbon, oxygen isotope and clumped isotope compositions were calculated as the average of 8–16 replicate analyses of 100–150 μg of carbonate. The carbon and oxygen isotope ratios are reported in δ notation in per mil (‰) relative to the Vienna Pee Dee Belemnite (VPDB), while the temperature-dependent mass 47 anomaly on the I-CDES90°C scale. Temperatures were calculated using the Kele et al. (2015) calibration modified by Bernasconi et al. (2018) and the Anderson et al. (2021) calibrations. Soil carbonates of the Esplugafreda formation yield δ13Ccarb values between –8.55 and –5.85 ‰, while the PETM yellow soil carbonates are significantly more negative (–13.84 to –10.12 ‰), in good agreement with previous measurements. A much smaller, ~1.2 ‰ difference can be observed in the oxygen isotope compositions between these carbonates (δ18Ocarb: –5.46 to –4.13 versus –6.35 to –4.47 ‰). The Δ47-based paleotemperatures (T47carb) indicate mean soil carbonate formation of 33.8±9.5 °C during the late Paleocene, which are close to modern summer temperatures of subtropical regions. By contrast, a much higher mean temperature was recorded by soil carbonates of the PETM yellow soils (39±8.5 °C) with extreme (>40 °C) temperatures occurring 4 times more frequently than over the late Paleocene. This study was supported by the NKFIH through the OTKA K-137767 project.

Provenance information from recent and ancient sedimentary archives is obscured by several factors and for disentangling these intermingled signals, analysis by multiple methods is paramount. In sedimentary provenance analysis (SPA), single-grain methods determining mineralogy, chemical composition, or radiometric ages are of key importance but are mostly applied to sand-sized sediments or sedimentary rocks. Finer grained sediments or sedimentary rocks are usually analyzed by whole-rock geochemical means and seldom by single-grain methods. Considering the abundance of fine-grained sedimentary archives, a strong need for single-grain, multi-method analyses of silt-sized sediments is obvious. Thus, we propose a workflow that is optimized for sample throughput and correlative analysis of fine-grained sediments based on machine learning methods. The feasibility of the workflow is demonstrated by differentiating three Central European loess-paleosol-sequences. The increased sample throughput enables access to sedimentary archives at high spatial and/or temporal resolution, which will open up new research pathways in SPA of silt-sized sediments. Deciphering the origin of sediments and sedimentary rocks is the main goal in sedimentary provenance analysis (SPA). This is usually done by determining the mineralogical and chemical composition or absolute age of the mineral grains that make up the sediment. However, the information gained from a single method is often insufficient to provide a complete picture in sedimentary provenance. Thus, many different methods are used, preferably on individual grains. Since analysis is easier and potentially more precise when done on larger grains, the sand-size fraction is usually investigated. Consequently, samples of finer grain size (e.g., silt) are less often measured. This is contrasting the fact that about 50% of sedimentary rocks are of such finer grain sizes. Therefore, an approach is required that allows to apply different micro-analytical tools to the same silt-sized minerals and combine the gained data. Here, we propose such an approach, which is based on machine learning methods and has been optimized for sample throughput. We successfully tested it's feasibility by differentiating Central European loess sequences. The high sample throughput of the approach will allow analyzing fine-grained sedimentary archives at high temporal resolution, thereby enabling new research pathways in SPA. Sedimentary provenance analysis relies on information derived from single-grain methods usually applied to sand-sized mineralsAn innovative workflow for correlative, single-grain analysis of silt-sized minerals is presentedAccess to sedimentary archives at high temporal and/or spatial resolution is enabled by the workflow