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Paleoclimatic constraints from mountain ranges separating major climate systems are important in understanding past climatic changes. Using the present-day glacial geomorphology combined with the GlaRe model, the last glacial maximum (LGM) of seven representative valley glaciers of the Pir Panjal Range (PPR), Kashmir Himalaya was reconstructed. The Range lies at the interface of the tropical and temperate climates in the NW Himalayas. The glacier reconstructions showed that the glaciers in the Range advanced ~10 km down the present-day cirque margins and attained a thickness of more than 200 m during the LGM. Using six different methods, the equilibrium line altitude (ELA) changes in the selected valleys of the PPR were estimated for which the LGM was reconstructed. ELA depressions calculated for the LGM vary from 374 m to 416 m with a mean of 395 m. The weighted average ELA of the Range lies at an altitude of 3922 m a.s.l showing a general increasing trend from SE to NW of the Range. The published chronology of the loess deposits, a proxy for glacial aridity, shows the evidence of significant glacial advances starting around 350 kya in the valley, which is consistent with the evidence of both the pre- and post-LGM advances observed in this study. The presence of extensive glacier features all across the PPR and the presence of a few small heavily debris-covered glaciers in the Range points towards the rapid deglaciation in the area.

The lowest section of the Upper Dniester River Valley (DRV), located between the uplands of Opillia and Eastern Subcarpathians, was a separate and specific Pleistocene geoecosystem, interesting for the hunter-gatherer communities. This is evidenced by three main (Yezupil, Mariampil and Halych), and a dozen or so additional Palaeolithic open-air sites. They occur as cultural layers within the loess-palaeosol sequences (LPSs) and represent semi-permanent settlement (except for the periods with the maximum intensity of the loess sedimentation); the oldest occur in the Eemian palaeosol. All sites are located on both sides of the river. In the past, the DRV was characterized by local environmental diversity changing with time. In consequence, it has very individual features, so the analysis of environmental changes is a local case study. In order to obtain information about the changes of climate and environment, the multi-proxy analyses were carried out. Chronology was based on the luminescence and radiocarbon dating. The diversity of habitats was local. Its degree was changing with time: it was minimal in the periods with extreme climatic conditions, such as the climate optimum and pessimum, and clearly greater in the climatically intermediate periods with fluctuations. Based on the materials indicating the mesoclimate and local vegetation diversity during the human occupation episodes as well as the location of the Palaeolithic sites, we found that generally the possibilities of choosing a warmer or sheltered place for a camp were not significant for hunters representing different cultures of different ages. Palaeolithic groups very often occupied the same places in the DRV. The camps had a hunting function, the choice of places was dictated primarily by the need to find a good place to observe game animals and to organize hunting – first of all – in the mouth sections of the tributaries of the Dniester River, regardless of the situation of localities relative to riverplains. The settlement attractiveness of such places was essentially timeless.

Sites identified as the Early Upper Palaeolithic (EUP or transitional industries) in Central Europe (CE) have become subject to extensive discussion on the possible interactions between anatomically modern humans and indigenous human species which inhabited the area in the Marine Isotopic Stage 3 (MIS 3, 50–35 ka BP). An open-air site Dzierzyslaw 1 (SW Poland), known for nearly a hundred years, played a crucial role in envisaging scenarios associated with the development and adaptation of the EUP society. In the late 20th c., due to the excavations in the southern part of the site, it was given status of a multicultural site, with artefacts assigned to the Micoquian, Bohunician and Szeletian culture. This paper presents the findings of the multi-faceted revision of this site. We present the results of field work and chronometric analyses based on a new set of samples and archaeological study of archive records. The use of optically stimulated luminescence (OSL) showed that all the sediments of the site should be assigned to the Plenivistulian (MIS 4/3 and MIS 2). The new chronometric assessment indicates the absence of deposits corresponding to the transitional industries' time window. The sedimentological data integrating with spatial distribution of finds and raw material variation as well as state of preservation and typo-technological features of lithic artefacts indicate that the inventory represents a compilation of the late Middle Palaeolithic (MP, Micoquian) and classical Upper Palaeolithic industries (Aurignacian or Gravettian) with very few pieces corresponding with indeterminate EUP industry. The revision throws a light on the situation in the Moravian Gate and areas north of the Carpathians and Sudetes. The results suggest that sites from the late MP are more numerous than those from the EUP. It seems that the over-representation may result from a long time of accumulation during the MP period. It cannot be excluded that the small number of EUP sites reflects a marginal role of the area north of the Sudetes and Carpathians in the human occupation system of that time.

Current dust storms, originating from afar, are common in Israel and the eastern Mediterranean, and thus most dust sources are considered to be distal. However, recent studies suggest that the latest Quaternary loess accreted in the Northern Negev can also serve as a proximal source of dust. These sources were mostly neglected in past discussions as contributors of dust. Here, we demonstrate that such proximal dust sources, mostly the Negev loess, currently contribute relatively large amounts of recycled dust to the regional dust cycle. We conducted a sampling campaign of deposited dust during individual dust storms and identified high content of coarse silt grains and quartzo-feldspathic minerals within and adjacent to the Negev loess that gradually decreases toward the north. These grains, characteristics of the Negev loess, indicate a short transport distance. In addition, our data reveal that local wind speed is the limiting factor for emitting proximal dust, regardless of the synoptic system. We determined that proximal sources in Israel emit dust during either local events or as a part of regional dust storms originating from afar. We evaluate the minimal contribution of this proximal dust to the total mass of deposited dust as 58–74%, 54–70%, 52–64%, and 26–34% for the northern Negev, central Negev, central mountainous region, and northern Israel, respectively. These estimates indicate that at the desert fringe, both proximal and distal sources of dust should be considered when inferring dust sources from dust geochemistry that can sometimes be similar due to the long dust history.

Typical patterns of the Late Pleistocene loess–paleosol units are preserved in the Novo Orahovo brickyard, Northern Serbia. Presented preliminary luminescence chronology supports the chronostratigraphic interpretations of global isotopic marine climate reconstructions. Magnetic susceptibility and sedimentological evidence exhibit general similarities with the marine oxygen-isotope stratigraphy. These records provide new insights into the dust accumulation regimes over the eastern side of the Bačka loess plateau and offer new paleoenvironmental information for the region. They represent an important step forward towards the establishment of a catena from the thin loess-like sediments of the Banat foothills in the east towards the thicker and seemingly more complete loess sections of the southeastern and central Carpathian Basin. Grain-size data from the loess record of Nova Orahovo explain the regional differentiation in dust deposition.

Loess deposits are widely spread all over Eastern Europe, extending as far south as the Sea of Azov and the northern Black Sea. For many decades these regions have been noted for series of key sections. However, despite prolonged investigations, a lack of absolute dating and detailed lithological data has left many unresolved problems in the correlation of the regional stratigraphic schemes. In this study, integrated studies were undertaken on the loess-paleosol sequence exposed on the northern coast of the Taman Peninsula, separating the Sea of Azov from the Black Sea. The exposure in the coastal scarp near Cape Pekla was sampled in detail for standard lithological and stratigraphic analyses, and for the first time, detailed data on the sediments lithology and petromagnetic properties were obtained, as well as the first optically stimulated luminescence age estimates. The data lead us to conclude that the formation of continental series exposed in the Pekla section started at the beginning of the Middle Pleistocene. There are five well pronounced buried soil complexes (PS 1–5) exposed in the sequence, covering sedimentation from the Middle Pleistocene to the present day. We attribute two lower paleosols (PS 4 and PS 5) to two main warm intervals of the Middle Pleistocene – MIS 9 and MIS 13, and the Kamenka interglacial paleosol, correlated with MIS 7 from other parts of the Azov loess area, is represented in the Pekla section by a sand layer formed at the time of the marine transgression dated to interval 220–280 ka (MIS 7). The upper soil horizons (PS1, PS2 and PS3) developed between 20 and 220 ka. The Pekla section contains a considerable proportion of sand fraction – presumably, due to active eolian processes that developed in immediate vicinities of sources of the material. The paleosol characteristics and the structure of loess horizons in the Pekla subaerial series differ considerably from the well described loess-paleosol series of the Northern Azov Sea coasts. In all probability, this region of the Taman Peninsula belongs to a specific province located south of the North Azov loess-soil province.

Chinese loess deposits provide a valuable archive of East Asian monsoon variations and compare well with marine oxygen isotope records. However, post-depositional pedogenesis disturbances during some long and warm interglacials may decrease the time resolution and recording efficiency of loess deposits. In this study, we build a simple multiple-state model that involves deposition and pedogenesis processes to simulate loess-paleosol grain size variations and evaluate the recording efficiency under the impact of pedogenesis disturbance. Meanwhile, the modeling results are compared with the measured grain size time series of Xifeng profile from the center of the Chinese Loess Plateau (CLP). The results show that the recording efficiency of the loess deposits in the central CLP has been stepwise enhanced since the early Pleistocene. High-latitude signals in the Chinese loess record between 2.5 and 1.6 Ma were partly erased by post-depositional pedogenesis and only those from several intense glacial periods remain better preserved. Three finer-grained loess units appear at ~550 ka (marine isotope stage (MIS) 14), ~1045 ka (MIS 30), and ~1500 ka (MIS 52), which were likely caused by low dust accumulation rates, suggesting the moderate growth of ice sheets in the Northern Hemisphere. After the mid-Pleistocene transition (~0.9 Ma), the occurrence of grain size changes related to precessional cycles within the long-term glacial periods did not appear in our modeling results. Such variations may thus represent changes of the dust source areas controlled by the East Asian summer monsoon. However, the suppression of precessional variations in the major paleosol layers indicates that loess deposits at least in the central CLP are a low time-resolution archive for capturing precession-scale paleoclimatic changes during interglacial periods.

The variability and dynamics of the Asian monsoon (AM, hereafter indicates both of the summer and winter monsoons.) at orbital and millennial timescales has attracted wide interest. Chinese loess deposits, covering an area of ~500 × 103 km2 and with a thickness of several tens to more than three hundred meters, is an ideal continental archive to reconstruct AM variations during the Quaternary epoch. Over the past thirty years, since the earliest paper published in an international journal that linked the Asian monsoon and Chinese loess deposits, many studies have been undertaken focusing on this research topic. These results have greatly deepened our understanding of the variations of the AM climate and their driving mechanisms during the past ~2.6 Myr. In this paper, we emphasize recent progress on the AM variability and dynamics revealed by Chinese loess records; in particular, we discuss the reliability and precision of the timescale and the monsoon proxy indicators for the loess-paleosol sequences, which are two fundamental aspects for understanding AM behavior. We analyze what we know and discuss what we do not know about the AM. We refine the timescale for the typical loess-paleosol sequence in the central Chinese Loess Plateau (CLP), which can be used as a new timescale to study palaeoclimate and palaeoenvironmental changes in the monsoonal Asia. We conclude that low-latitude insolation changes induced by precession, and global ice volume, temperature at high-latitudes, as well as sea-level changes forced variations of the AM at orbital time scales. High-latitude cooling events and low-latitude hydroclimate process at millennial time scales, such as climate changes associated with Heinrich events and Dansgaard-Oeschger cycles in Northern Atlantic and Greenland, have also modulated AM variability. We suggest that high-latitude forcing of AM variations occurs through ocean and atmospheric circulation linkages, although the roles of atmospheric CO2, ocean and vegetation feedbacks need further investigation. In future study, high-resolution independent dating, novel proxy indices and transient numerical simulations are still basic tools to understand the loess deposition and AM variations that require considerably more work. Issues such as reliable spatial comparison and regional linkages of records (dependent on precise and accurate numerical chronologies), and quantitative reconstruction of the AM variations, should be given priority in the study the past climate change in Asia, and low-latitude hydroclimate process.

© 2020 Elsevier Ltd and INQUA Eurasian loess-paleosol sequences provide continuous records of global change in mid-latitude Northern Eurasia. The loess-paleosol sequence of West Siberia located in the central part of the mid-latitude Eurasian loess belt extending from West Europe to Yakutia is an outstanding paleoclimate archive in Northern Asia. The stratigraphy has been best documented on the left bank of the Ob River, in the so-called Ob Loess Plateau. This study focuses on the stratigraphy of the most complete Middle-Late Pleistocene loess-paleosol sequence at the Belovo section. The suggested high-resolution model of the Belovo Late Pleistocene stratigraphy is based on magnetic and sedimentological proxies and is correlated with other Eurasian loess records and with the global marine δ18O stratigraphy. The enviromagnetic signal at Belovo Loess-paleosol sequences shows a transitional pattern comparable with both typical Eurasian loess magnetic records. Detailed paleopedological interpretations of the magnetic and sedimentological data from the Belovo section have important implications for appropriate linking different Late Pleistocene climates and environments of other the well-known Eurasian loess provinces.

The Nihewan Basin is one of the most important areas for the study of early human evolution and land mammals in East Asia. More than 100 Paleolithic sites have been discovered in the basin, spanning the Early Pleistocene to the Late Pleistocene. The chronological framework for the Early Pleistocene sites is well established using magnetostratigraphy. However, few independent ages are associated with Middle Pleistocene sites; one such example is the Hougou Paleolithic site, where interpolated magnetostratigraphic ages are not precise and accurate enough, owing to the artifact layer of the site is far relative to the Matuyama/Brunhens (M/B) boundary. In this study, we use the ESR signals of Al and Ti–Li centers in quartz to date the Hougou site. The advantages of the regenerative dose method over the additive dose method were discussed. Our ESR results indicate that the age of the Hougou Paleolithic site is between 436 ± 30 and 416 ± 42 ka, approximately with an average of 426 ± 36 ka, which corresponds to Marine Isotope Stage (MIS) 12 or loess layer L5. In addition, the disappearance time of the eastern part of the Nihewan paleolake may be approximately 430 ka.

We present results for three sections with a representative loess record of the end of the Late Pleistocene from the south-east of Western Siberia. These sections are characterized by different structure and formed in different geomorphological position of Ob Loess Plateau and Cis-Salair plain. The age of deposits within MIS 1 - MIS 3 is determined by radiocarbon and OSL dating. Data on the quartz grain morphology confirmed that aeolian processes were the main factor in the accumulation of studied profiles, the influence of cryogenic weathering was also noted. Evidence of the MIS 2 warmings have been recorded in the northwestern Salair region (Ust’-Chem section), presented by two weakly developed Late Glacial paleosols formed 14.9–12.3 kyr ago. The distribution of magnetic susceptibility and grain size records in the Lozhok and Klyuchi sections reveals a period of relatively long term aridization with an increase in atmosphere dustiness in the lower part of the Eltsovka loess (MIS 2). The trend of increase in humidity with decrease in the atmosphere dynamics is observed during the second part of MIS 2. An event of activation of local aeolian processes with dune formation took place 47 kyr ago (the first half of the Karga interstadial; MIS 3) in the Klyuchi section. It is supposed that the geomorphological situation and the presence of nearby material available for local redeposition was a significant agent in the formation of the lower layer of Klyuchi and Ust-Chem sections. It was formed by combined deposition of silt material from the atmosphere flow and by the local aeolian transportation of sand. Permafrost-solifluction event was established in the northeastern part of the Ob Loess Plateau at about 23 ka.

This review serves as an explanatory note to the sketch map of loessoids, i.e. loess and various loess-like deposits. The map is a byproduct of the ongoing project of Quaternary Map of the Russian Federation, scale 1:2,500,000 in GIS-format. The primary information is derived from the standard National Geological Map scale 1:1,000,000 of the last two generations supplemented by literary data. The map polygons present all mappable loessoid units, including thick southern carbonate loess with paleosols, loess-like silts of northern terrains, intercalations of loessic sediments with waterlain facies and icy silts of the Arctic and Subarctic type. The loessoid formations are classified according to their stratigraphic intervals: 1) the radiocarbon dated Upper Pleistocene of northern terrains, 2) the Middle plus Upper Pleistocene of central Russia, 3) the late Lower Pleistocene to Upper Pleistocene series of southern regions and 4) the Lower Pleistocene red clays of the south. The distribution of diverse loessoids is an imprint of: i) the diverse sedimentary environments of the basically arid periglacial zones of the Pleistocene and ii) the modern geographical zonality changing from subtropics to the icy High Arctic and responsible for post-depositional alteration of subaerial dust. Whatever the origin of the primary dust and geographical varieties of the diagenesis, all loessoids share the same fundamental feature – paleosols, whether numerous and expressive or scarce and weak. They underline the climatically driven intermittent process of loessoid formation – basically subaerial and independent of any aqueous agencies.

The geochemical composition and magnetic susceptibility (MS) of three sections (Weinan, Jingchuan and Jingbian) in the central Chinese Loess Plateau, located along a north-south climate gradient, were analyzed at high resolution in order to reconstruct changes in weathering intensity and hence Asian monsoon evolution during the Holocene. The results show distinct differences in element composition between the loess and paleosol layer, as well as spatial differences which reflect changes in mean annual temperature and annual precipitation along the climatic gradient. The measured major element compositions, combined with the results of previous research, indicate that the provenance of the Holocene loess-paleosol sequences in the central Chinese Loess Plateau was constant over time and space. The degree of chemical weathering in the study area is relatively weak and at an intermediate weathering stage. Based on a magnetic susceptibility age model, the East Asian summer monsoon changes recorded by the loess-paleosol sequences show a distinct two-stage pattern of evolution, with a gradual increase during 13.1–8.5 ka and a gradual decrease thereafter. Comparison of the results with climate records from elsewhere indicates that the East Asian monsoon evolution was mainly controlled by changes in Northern Hemisphere summer insolation and ice sheets.

The interglacial periods of the Pleistocene (MIS 5) and Holocene have been widely studied as analogs, whereas the records of the penultimate interglacial complex (MIS 7) are relatively sparse. In this study, based on a multitude of proxies, such as magnetic susceptibility, geochemical elements and their ratios, and grain size spanning MIS 7 of Xiashu Loess, the paleoclimatic changes that are synchronous with the five episodes during MIS 7 are reconstructed in the Chaohu Lake Basin, East China. It is proposed that the paleoclimate change in the Chaohu Lake Basin during MIS 7, on orbital time scale, might be controlled by low-latitude insolation; on millennium scales, might be directly driven by the global ice volume variations.

To better understand interglacial paleosol development by quantifying the paleosol development processes on the Chinese Loess Plateau (CLP), we need a soil genesis model calibrated for long timescales. Here, we calibrate a process-based soil genesis model, SoilGen2, by confronting simulated and measured soil properties for the Holocene and MIS-13 paleosols formed in the CLP for various parameter settings. The calibration was made sequentially on three major soil process formulations, including decalcification, clay migration and soil organic carbon, which are represented by various process parameters. The order of the tuned parameters was based on sensitivity analyses performed previously on the loess in West European and the CLP. After the calibration of the intrinsic soil process parameters, the effect of uncertainty of dust deposition rate on calibration results was assessed. Our results show that the simulated soil properties are very sensitive to ten reconstructed dust deposition scenarios, reflecting the propagation of uncertainty of dust deposition in model simulations. Our results also show the equal importance of calibrating soil process parameters and defining correct external forcings in the future use of soil models. Our calibrated model allows interglacial soil simulation in the CLP over long timescales.

A combined survey including infrared thermography (IRT) and field-laboratory tests were conducted to analyze the thermal responses and thermal properties of loess on a landslide-prone loess slope in the Heifangtai terrace in Northwest China aiming at preliminarily demonstrating the potential of IRT as a complementary technique to the investigation of irrigation-induced loess landslides. Multitemporal thermographic surveys corresponding to various solar radiation intensities during the afternoon were carried out on the landslide-prone loess slope. Accordingly, the spatiotemporal distribution of the thermal responses within the observed slope surface was analyzed qualitatively and quantitatively. Meanwhile, field and laboratory investigations were also performed on the thermal properties of different landslide materials. The results indicate that loess, a landslide-prone deposit that usually has a relatively high water content, exhibits different thermal properties and anomalies, including a lower surface temperature and greater thermal inertia, compared to surrounding zones without landslides. The groundwater table and corresponding seepage line could also be obtained by determining the potential boundary between the thermal response distribution of landslide scarps and that of saturated deposits in the presence of landslides. The results of these investigations are expected to provide insight for future endeavors combining infrared thermography with other efficient survey methodologies (e.g., InSAR, which can monitor the active displacement of a loess slope) to evaluate the activity of this kind of excessive irrigation-induced loess landslide.

Loess landslides are one of the most serious geological disasters in the Chinese Loess Plateau. Research has revealed that earthquake, rainfall, and human activities are common triggers for loess landslides. In order to study the relationship and characteristics of these landslides triggered by different factors, the paper uses historic landslide data to expound the basic motion indices of landslides triggered by different factors. More than half of loess landslides occurred on concave surface slopes, while nearly 40% of the loess landslides occurred on convex surface slopes. Human activities have a great effect on the occurrence of landslides, and the distribution density of landslides on residential land was almost five times that of bare land. Additionally, earthquake-induced loess landslides had the largest sliding volume, whereas the excavation-induced loess landslide had the smallest sliding volume. The sliding volume of irrigation-induced and rainfall-induced loess landslides were between earthquake-induced loess landslides and excavation-induced loess landslide. Many of loess landslides were induced by a combination of these factors, such as rainfall and excavation, irrigation and excavation. Then a model that described the impact of these factors on the loess landslides was proposed.

Purpose Suspended sediment transport, which represents the majority of the sediment load, has been studied across very different scales and in a wide variety of regions and climates. Despite numerous studies, data for European watersheds are generally limited and correspond to large rivers systems. Especially, in Belgium, little data is available outside the Belgian loess belt. Moreover, the high heterogeneity of soil erosion and sediment transport makes it difficult to measure or model at watershed scale. The purpose of this research is to estimate the median sediment yields in different geographical regions and to detect their explanatory variables. Materials and methods Gathering data from 1994 to 2016, more than 2000 measurements of suspended sediment concentration at 72 river stations mainly located in South-Belgium were sampled according to a flood-event-based manual methodology. This allowed fast acquisition of data in watersheds ranging from 7 to 3600 km2 in different geographical regions. Median area-specific sediment yields (SSY) were calculated at watershed scale while looking for regional differences. Results and discussion Median area-specific sediment yields computed for the period 1996–2018 show regional differences: 19.2 t km−2 year−1 on sandy substrate (Lorraine), 24.9 t km−2 year−1 on schisto-sandstone substratum (Ardenne), and up to 119 t km−2 year−1 in the loamy Brabant plateau, with a link to the agricultural land cover and, to a lesser extent, to the watershed slope. The high temporal and spatial variability of rainfall has great effects on the SSY, necessitating the gathering of more than 20 years of data to smooth the high variability of SSY. A multiple correlation of land cover variables and the average slope of the watershed with SSY managed to explain 48% of the variance within the SSY observations. Conclusions The agricultural land cover has an important effect on median SSY values. While the regionalization of Belgium is largely based on lithology, soils, and altitude, the land use resulting from these physical and climatic characteristics explains the differences in SSY. Field values of clogged dams and waterways confirm the matching of the SSY computation from discrete samples, despite the high temporal variability of sediment transport.

Micromorphological investigations of loess-paleosol sequence offer the potential for understanding pedogenic and paleoclimate change at the microscopic scale. However, the micromorphological study is comparatively scarce in the south Qinling Mountains, China. Here, micromorphological analysis (coarse particles, pedofeatures and voids) in conjunction with physicochemical indexes of pedogenesis (i.e., clay content, CaCO3 and Fe2O3) were carried out from two Holocene loess profiles in the upper Hanjiang River. These results show that: (i) Paleosol is considered as strongly-developed soils on basis of much finer and rounder particles, channels, more reddish color and abundant illuvial clay coatings; (ii) Lessivage (clay formation, eluviation and illuviation), intensive carbonate eluviation and rubification were identified as the major pedogenic processes of paleosol; (iii) Comparative study with Chinese Loess Plateau (CLP) indicates that loess deposits in the south Qinling Mountains experienced a much stronger pedogenesis as evidenced by multiple generations of illuvial clay and almost completely eluviation of carbonate, which implies a warmer and wetter paleoclimate in the subtropical monsoon zone. The pedogenic differences across the Qingling Mountains are mainly controlled by regional paleoclimatic differences and provide a good response to monsoon climate change in the East Asian.

The gully is the most dynamic and changeable landform unit on the Loess Plateau, and the characteristics of gully landforms are key indicators of gully evolution. Different gully profiles are connected and combined through runoff nodes. Thus, it is necessary to cluster gully profiles into a gully profile combination (GPC) to reveal the spatial variation in gully landforms throughout the Loess Plateau. First, the gradient and gully evolution index (GEI) of two sample areas in Changwu and Suide in Shaanxi Province, China are calculated and analysed based on GPC. Then, the gradient and GEI are calculated by using 90-m-resolution digital elevation model (DEM) data for the severe soil erosion area with the basin as the research unit. On this basis, the spatial variation in the development degree is analysed with Getis-Ord Gi*. The results show that the degree of gully undercutting decreases from southeast to northwest under the influence of rainfall. Due to the soil properties, the loess in the northwest is more prone to collapse, resulting in the decrease of GEI from northwest to southeast. The development degree of gullies is closely related to rivers. The strong erosive capacity of rivers leads to greater differences in gullies within the basin. At the same time, the skewness and kurtosis of the gully index in the basin are correlated; when the distribution of the gully index in the basin is less normal, the distribution of the gully index is more concentrated. These results reveal the spatial variation characteristics of the Loess Plateau based on GPC.

Although there are still some conflicts, previous studies based on lacustrine or aeolian deposits provide an overall understanding of the Holocene environment in the Qinghai Lake Basin. Compared to lacustrine deposits, aeolian sediments have received less attention, and the loess on the south coast and the Hudong Sandy Land on the east coast has received the most attention. The Ganzihe Sandy Land, the second largest sandy land in the Qinghai Lake Basin, is far from lakeshore areas and shows an obvious degradation trend. Very few reports have been published on the Ganzihe Sandy Land, especially regarding the Holocene environment. Here, we report a new and well-reserved aeolian sand-paleosol profile found in the Ganzihe Sandy Land. We used 7 optically stimulated luminescence (OSL) and accelerator mass spectrometry (AMS) 14C dating to establish the chronological framework and measured the magnetic susceptibility (MS), grain size, color parameters and total organic carbon (TOC) in the profile. Combined with lithologic changes and chronological data from published aeolian profiles, the results indicate that the aeolian activity in the Ganzihe Sandy Land during the Holocene was mainly affected by climate change in marginal monsoon areas by at least ~10 ka; the climate then improved, and vegetation began to develop from ~10 ka-~8 ka; from ~8 ka-~4 ka, the climate was warm/wet and stable, dunes were fixed and the sandy land entered the “Holocene climatic optimum”; since ~4 ka, the regional climate has gradually become drier and cooler, and aeolian sand has again accumulated on a large scale, particularly in the past thousand years. To prevent further environmental deterioration in the Ganzihe Sandy Land, we believe that straw-breaks should be established and increasing efforts should be made to artificially enclose the mobile dune region inside the sandy land, control the amount of animal husbandry and emphasize water conservation in the marginal areas. Further, sand control stations should be set up to carry out land monitoring and forecasting, and local residents should be educated about scientific and legal issues.

The sediment transport capacity provides a theoretical basis for accurate prediction of soil erosion. The aim of this study is to develop a sediment transport capacity prediction model applicable to a variety of soils. Sandy loess and loess soil (d50 = 0.095 mm and d50’ = 0.04 mm) were used to conduct indoor sediment transport experiments under different hydraulic conditions. Moreover, the experimental data of cohesive soil and cohesionless sand was combined, and the response relationship between sediment transport capacity and each flow intensity parameter was analyzed through dimensionless processing. Results showed that the sediment transport capacity had an exponential function relationship with unit discharges and energy slopes. The sediment transport capacity also varied with the changing flow intensity parameters, and through analysis, the effective stream power was observed as an optimum predictor (R2 = 0.9692). Considering the effective stream power and volumetric sediment concentration, this study derived a formula for calculating the sediment transport capacity. In conclusion, this study innovatively established a prediction model of sediment transport capacity on loessial slopes though regression analysis and dimensionless method. The proposed model is capable of considering flow intensities and volumetric sediment concentration simultaneously, and has a superior applicability to both cohesive soil and cohesionless sand compared with the four main existing models.

In recent years, the acceleration of urbanization in loess areas has prompted frequent dismantling and reconstruction of old urban areas. Demolition and reconstruction of buildings involve multiple collapses of the foundation. To study microstructure evolution of loess under multiple collapsibility, this paper selects undisturbed loess samples from Guyuan, Northwest China for multiple compression tests. Using nuclear magnetic resonance (NMR) imaging and scanning electron microscopy (SEM) as auxiliary methods, a combination of qualitative and quantitative analyses was used to study the microstructure of loess samples before and after various number of collapses under different pressures. Results show that the loess does undergo multiple collapse under 200 kPa pressure. Pore is an important reason for loess collapse. The initial collapse comes primarily from the compression of macropores and mesopores, and the second collapse comes primarily from mesopore compression. The compression process of loess can be roughly divided into two stages. First, under the action of dissolution and compression, the relative displacement of soil particles occurs. Macropores and mesopores are destroyed first, generating small pores. Second, with increasing pressure and times of collapses, pore compression gradually transforms into small pore compression. During the first collapse, particle aggregates disintegrate due to water and pressure. However, with increasing times of collapses, the contact relationship between particles gradually changes from the point contact to face contact. Loess particles tend to gradually become rounded. The study of the microstructure provides the possibility to further reveal the mechanism of multiple collapsibility of loess.

Terracing greatly affects soil properties, ecosystem services, human welfare and geographical sustainability. The purpose of this article is to determine the influence of terracing on soil properties across diverse regions in China. Three representative terrace types, including dryland loess terraces, dry-stone terraces, and paddy terraces, were selected as case study areas. Soil sampling was stratified according to thickness of soil layers in each terraced area. Based on field investigations and soil sampling, combined with the means of variance, correlation, redundancy and regression analysis, we analyzed the characteristics of soil properties in the terraces across three areas. Results showed that: (1) alterations of soil physicochemical properties mainly depend on differences between soil parent materials in such regions; (2) Due to the existence of “four-element isomorphism” in the ecosystem and reasonable human activities, paddy terraces had the greatest impact on soil properties which is mainly reflected in decreasing soil pH and increasing SOC, TN, and TK; (3) The content of SOC and TN in different areas was higher in terraced fields than in the sloped lands and decreased with soil deepening; (4) To maintain sufficient supply of soil nutrients and support the sustainability of agricultural terraces, it is necessary to apply manure to improve soil fertility and accelerate its aggregation in the terraces. For example, an increase in the application of nitrogen fertilizer in terraced fields in Hebei and Gansu provinces, which have a serious deficiency in soil available phosphorus (AP), is necessary to get greater amounts of P fertilization. The present study offers a theoretical foundation for the sustainability of terraced ecosystems through efficient crop production, which is the basis for strengthening the ecological security of terraced areas and promoting regional sustainability in those fragile mountains.

Whereas loess-mudstone landslides are widely distributed and frequently occurred at the loess Plateau, this type of landslides is hard to detect due to its particularity, and easily generates serious losses. To clarify the shear characteristics and formation mechanism of loess-mudstone landslides, field investigations, ring shear tests and numerical simulation analyses were performed on the loess specimens collected from the Dingjiagou landslide in Yan’an city, China. The test results showed that both the peak strength and residual strength of slip zone soils have a decreasing tendency with moisture content, while the increasing of normal stress caused an increase in the shear strength. These phenomena indicate that the rise in the moisture content induced by precipitation or the decreasing of normal stress due to excavation activities would result in the weakening of slip zone soils. Numerical simulations of the evolution process of slope failure using the finite element method were conducted based on the Mohr-Coulomb criterion. It was found that the heavy precipitation played a more important role in the slope instability compared with the excavation. In addition, the field investigation showed that loess soils with well-developed cracks and underlying mudstone soils provide material base for the formation of loess-mudstone landslides. Finally, the formation mechanism of this type of landslides was divided into three stages, namely, the local deformation stage, the penetration stage, the creeping — sliding stage. This study may provide a basis for understanding the sliding process of loess-mudstone landslides, as well as guidelines for the prevention and mitigation of loess-mudstone landslides.

We conducted the first detailed mineral magnetic investigation of more than nine loess–paleosol couplets of the composite Titel-Stari Slankamen loess section in Serbia, which provides one of the longest and most complete terrestrial record of paleoclimatic changes in Europe since ~1.0 Ma. The results show that the ferrimagnetic mineral assemblage of the loess units is dominated by partially oxidized multidomain (MD) and pseudo-single domain (PSD) magnetite; however, with an increasing degree of pedogenesis, the eolian contribution is gradually masked by pedogenic superparamagnetic(SP) and single-domain (SD) ferrimagnets (mainly maghemite). The overall consistency of ferrimagnetic grain-size parameters indicates an absence of dissolution of the fine-grained ferrimagnetic fraction despite changes in climate regime over the past 1.0 Ma. The variations of normalized dJ/dT@120Kand normalized χheating@530°Creflect a long-term stepwise increase in aridity during glacials with a major step at ~0.6–0.5 Ma, over the last 1.0 Ma. Overall, the results provide an improved basis for the future use of the magnetic properties of Serbian loess deposits for paleoclimatic reconstruction.

Wind erosion, or the transportation and deposition of sand into desert dunes and aeolian loess, is one of the most important aeolian activities. The progression of aeolian landforms expands arid and barren landscapes, leading to the degradation of adjacent areas. The Gonghe Basin, as a typical plateau with abundant sand sources, is highly sensitive to changes in the local climate conditions. In order to quantify the spatial-temporal variations in the aeolian landforms in the Gonghe Basin, we conducted field surveys and also analyzed twelve remote sensing (Landsat5 TM and Landsat8 OLI) images that sample the Gonghe Basin from 1989 to 2019. In the Gonghe Basin, we identified aeolian landforms such as climbing dunes on the windward slopes of the foothills, checkerboard dunes in the southeastern part of the basin, flat dunes, parabolic dunes and crescent dunes on the east and west sides of Longyangxia Reservoir, shrubby sandbanks on the valley slope in Shazhuyu, Tanggemu, and Indel, and sandy thickets at the bottom of the valley near the Dalian Sea, the Longyangxia Reservoir, and the tributaries of the Yellow River. From 1989 to 2005, the area of the aeolian regions expanded by 816.7 km2, with an annual conversion rate of 0.05%. From 2015 to 2019, the area of the aeolian regions shrunk by 2411.9 km2, with an annual conversion rate of −0.15%. The number and size of the fixed and semi-fixed dunes (e.g. the shrubby sandbanks on the valley slope and the sandy thickets at the bottom of the valley) were more stable than those of the mobile dunes (e.g. the checkerboard dunes, the flat dunes, the crescent dunes, the parabolic dunes, and the climbing dunes). The fixed and semi-fixed dunes were arranged in an irregular ring shape, and the location of the center of gravity of this ring did not change significantly from 1989 to 2019; in this time, the mobile dunes migrated to the northwest.

The Quaternary aggradation red earth (QARE) deposit in the middle reaches of the Yangtze River (MRYR) in southern China provides important evidence for understanding the paleoenvironment. However, its provenance remains controversial. In this study, the surface microtextures of grains from the QARE were observed, and compared with those of grains from the loess deposit on the Loess Plateau in northern China. The results show that the surface microtextures and morphologies of the quartz grains in the QARE are distinctly different from those in the northern loess, indicating that the deposits in the two regions have different provenances. The Gobi and deserts in inland northwestern China are not considered as the primary provenance for the QARE in southern China. It is suggested that the large areas of dry and bare river and lake beds and floodplains in the MRYR, which became exposed during glacial periods, provided the dominant source for materials in the QARE. We suggest that against the background of the middle-Pleistocene climate transition (MPT), regional aridification and a strengthened east Asian winter monsoon (driven by global cooling and the rapid uplift of the Tibetan Plateau) were primary drivers for the initiation of the QARE deposit in the MRYR region in southern China. The development of large areas of aeolian red earth deposit is direct evidence of environmental deterioration in the MRYR, indicating a cold and dry environment with frequent aeolian activity, in an area that now experiences a warm and humid subtropical monsoon climate. The results are also evidence of a regional response in the mid-subtropics of southern China to the MPT global cooling event around 1.2 Ma.

This review paper presents a comprehensive study of all available up to date anthracological assemblages recovered from 79 archaeological settlements of the Neolithic and Bronze Age periods from the loess regions of southern-Poland. The aim of the research is to reconstruct the character of the woodland developed in the loess belt (1) in the Atlantic phase, with a focus on the primeval forests, the successive cultural phases and their impact on local forests, and (2) in the Subatlantic phase, characterized by a late-migrating of trees such as hornbeam, beech and fir. For the Early Neolithic period, related with the first appearance of the stable and agrarian settlement, the research aims at testing the hypothesis about the existence of open oak-dominated forests in the Atlantic phase , with patches of steppe-like vegetation. The anthracological data indicate that indeed open canopy forests prevailed in the loess-mantled areas and this result has important implications for understanding the expansion of the first farmers into Central Europe, who settled mainly in loess belt zones. It is likely that open oakwoods played a significant role in the selection of the landscape suitable for settle down as well as was an indicator of rich soils developed on loess-substratum. Finally, the last-arriving trees in southern Poland, that are principal constituents of present-day forests communities, appeared in high shares in the second half of the 2nd millennium BC, but became important forest components mostly in the Carpathian Foothills.

Unsaturated loess in natural sites loses stability as the overburden load continuously increases. Traditional soil modifiers such as cement and fly ash affect the surrounding environment. A new type of material, i.e., lignin, is environmentally friendly and able to increase the strength of loess. However, the engineering characteristics of the improved loess under unsaturated conditions are not yet clear. In this study, the soil-water characteristic curves (SWCCs) of lignin-improved loess samples were determined from 0 kPa to 700 kPa using a pressure plate instrument, and then, they were fitted using the van Genuchten (VG) model and the Fredlund and Xing (FX) model. In addition, the effects of the lignin content and sample preparation methods on the SWCCs were investigated to determine the optimal lignin content and a suitable sample preparation method for loess foundations. As the lignin content increases, the matric suction and residual water content of the improved loess increase. The suction stress increases with the increasing lignin contents of 1%–2%. At lignin contents of 3%–4%, the suction stress begins to decrease and the samples prepared using the slurry method has a lower suction stress than that prepared using the wet mixing method. The air entry value (AEV) increases with increasing lignin content. In addition, scanning electron microscopy (SEM) was used to investigate the microstructural variations. It was found that after the addition of lignin, the entrapment of the loess particles by the lignin fibers created some larger particles and smaller pore diameters, which in turn led to poor connectivity of the loess pores. These changes cause the matric suction of the modified loess to increase.

Srednaya Akhtuba outcrop provides a detailed record of the Late Pleistocene continental and marine deposits and paleosols from MIS5 to MIS1. The MIS5 chronozone is presented by a continuous pedosedimentary sequence with three well-developed paleosols. The paper is based on the study of depositional environment and pedostratigraphy, with OSL chronological framework and precise altitude references. Field data are supported by chemical analyses, micromorphology, and clay mineralogy. A detailed study of MIS5 paleosols was first conducted for the Lower Volga area. Pedosedimentary sequence at that time developed on the river terrace in a backswamp and/or wetland influenced by extremely slow-moving stream after long seasonal floods. Thin loess layers were deposited during the brief episodes of low flood activity, while fluvial heavy loams – at the time of more intensive flooding. Mollic Gleysols and Fluvic Chernozems have been formed in the arid or semi-arid climate with seasonal freezing under productive wet meadows. Changes in the depositional environment resulted in the formation of welded paleosols, marked by textural difference, cryogenic levels, and accretionary humus horizons. Despite the complicated depositional pattern and the influence of seasonal floods, the MIS5 pedosedimentary sequence may serve as a good stratigraphic marker for the onset of Late Pleistocene allowing correlation with loess-paleosol sequences of the whole Ponto-Caspian region and linking it with the global stratigraphic schemes.

Permafrost is considered to be one of the important sources of additional water for the vast Late Quaternary Caspian Sea transgressions. The insufficiency of proxy evidence on landscape and climate dynamics during the long Atelian regression (MIS 4 – MIS 3) complicates the analysis of changes in the Caspian water balance. Traces of Late Pleistocene cryogenesis structures were catalogued in the alluvial and loess-soil deposits of the Srednyaya Akhtuba reference section. Four stages of permafrost development were described for the first time in the Lower Volga region. Under conditions of seasonal and longer-term freezing in the Late Pleistocene, cryogenic transformation of the deposits took place; this determined the composition, structure and properties of the loess-paleosol complex at the site. Cryolithological, micromorphological analyzes and particle size distribution of mineral matter were carried out for each horizon, and traces of cryogenic processes were described in order to evaluate the regional paleoclimatic conditions that prevailed during their formation. Optically stimulated luminescence dating was used to establish a chronological framework for the main phases of the development of cryogenic modification in the Lower Volga region. The fourth stage of formation involved deep cracking of the substrate, which occurred during freezing in MIS 4, coincident with the Atelian regression of the Caspian Sea. The third stage is expressed as large wedge-shaped structures (pseudomorphs) on the border of loess and alluvial packages, with their formation known to be associated with the degradation of ice wedges. During the second and first stages of freezing, plastic deformation of deposits occurred.

Due to the high preservation of the loess series and the availability of coastal outcrop sections loess cover of Western Ciscaucasia has ample opportunities for spatial paleogeographical reconstructions for the Middle and Late Pleistocene. Currently, the level of knowledge on the structure and composition of the loess-paleosol sequences of Western Ciscaucasia remains unequal. The Azov coast is studied in more detail in comparison with the inner part of the region. The structure and composition of the loess-paleosol sequences of different parts of Western Ciscaucasia (the Sea of Azov coast and western macroslope of the Stavropol Upland) for the Middle and Late Pleistocene are compared. Comparison of the key sections are based on litho- and pedostratigraphy, magnetic susceptibility, grain size, elemental and mineral composition, and luminescence dating. Recent results of luminescence dating allowed correcting the structure of the Mezin pedocomplex (S1). It was found out that this pedocomplex includes three phases of soil formation (S1SS1, S1SS2, S1SS3), which approximately correspond to the warm stages of marine isotope stage 5 (MIS 5) – 5a, 5c, 5e. In all sections, a clear trend towards an increase in the accumulation rates over the last three climatic macrocycles is observed. The last interglacial-glacial macrocycle (MISs 2–5) is characterized by the most significant increase in average accumulation rates, which were ∼1.8 times higher compared to MISs 6–7 and ∼2.3 times higher than during the MISs 8–9. A likely reason for the regional increase in the average dust accumulation rate was the directional increase in climate aridity. The patterns of the spatial distribution of the loess thickness and material composition indicate that the main source of aeolian dust is situated in the east. We suppose that the main sources of dust are sand masses of the alluvial plains of Lover Volga, Terek, Kuma and Kura rivers in the Caspian lowland. The Lower Don sandy province is reconstructed to be a secondary source. Dust is blown from the sandy terraces of the Don, and in the past - from the Don deltas, during the period when the Sea of Azov dried up.

The paper presents the results of the newly discovered Epigravettian site situated in the San river valley in the Carpathian foreland close to the Przemyśl Gate – sub- and cross-mountain route. The site lies at the edge of that culture's post-LGM re-settlement of that area. It is a unique remnant documenting the presence of an Epigravettian Culture community in areas at the very same time occupied by Magdalenian Culture people. The geological multiproxy record allows for the reconstruction of a loess plateau with an open landscape, with marked presence of trees, plus a short episode of more favourable climatic conditions following shortly after Heinrich event 1. At that time, a group of Epigravettian hunters established a short term camp close to the edge of the loess terrace on the left San River bank.

The Wufo Basin at the margin of the northeastern Tibet Plateau connects the upstream reaches of the Yellow River with the lowland catchment downstream, and the fluvial terrace sequence in this basin provides crucial clues to understand the evolution history of the Yellow River drainage system in relation to the uplift and outgrowth of the Tibetan Plateau. Using field survey and analysis of Digital Elevation Model/Google Earth imagery, we found at least eight Yellow River terraces in this area. The overlying loess of the highest terrace was dated at 1.2 Ma based on paleomagnetic stratigraphy (two normal and two reversal polarities) and the loess-paleosol sequence (12 loess-paleosol cycles). This terrace shows the connections of drainage parts in and outside the Tibetan Plateau through its NE margin. In addition, we review the previously published data on the Yellow River terraces and ancient large lakes in the basins. Based on our new data and previous researches, we conclude that the modern Yellow River, with headwaters in the Tibet Plateau and debouching in the Bohai Sea, should date from at least 1.2 Ma. Ancient large lakes (such as the Hetao and Sanmen Lakes) developed as exorheic systems and flowed through the modern Yellow River at that time.

Here we present loess deposits since the late glacial dated by OSL technique in the southeast of the Caspian Sea, bordering continents of Asia and Europe. Chronology of Holocene loess deposits are rarely reported in Eastern Europe and Western Asia, especially for their spacious mid-latitude adjacent region, between Balkans to the west and Pamirs to the east. In this study, an OSL-based chronology was developed for loess deposits in northern Iranian Plateau, based on the YBD loess profile which locates close to center of hilly Iranian Loess Plateau in the southeast of the Caspian Sea and on the northern slope of the Alborz Mountains. The OSL characteristics and their reliability were investigated on coarse-grained quartz (63–90 μm) of the profile, a preheat plateau test and dose recovery test of which reveal that the lower preheat is suitable for loess equivalent dose determination in the area. In addition, the SAR-OSL is an appropriate methodology for dating loess deposited since the late glacial in situ. With preservation of a complete record of loess accumulation since the late glacial, YBD section contains a potentially valuable paleoclimatic record for Caspian region and hence the vast transitional region between Asia and Europe.

This paper reviews the current state of knowledge about environmental changes at the MIS 3/2 transition in the northern Alps and their foreland, covering the time frame from 35 to 25 ka. Lake and peat deposits, cave sediments, loess and glacial deposits are presented and the response of their biotic and abiotic proxies to climate change is discussed. During late MIS 3, interstadial conditions, albeit weak, occurred at c. 36–32 ka. At climatically favourable sites, small patches of trees (mainly Pinus and some Betula) existed together with some shrubs. The environmental conditions during late MIS 3 are also reflected by a boreal brown soil horizon, a cambisol called Lohne soil, found in many loess sequences. Subsequently, the environmental conditions became harsher as shown by the proxy data. From c. 30 ka onwards the absence of pedogenesis sensu stricto and the plant assemblages point to an Arctic climate in the northern Alpine foreland. Accentuating, glaciers advanced beyond the northern limit of the Alps around the MIS 3/2 boundary and reached their maximum extent in the foreland at about 25 ka.

Aeolian deposits, widely distributed in the Qinghai Lake area, provide independently palaeoclimatic information. Herein we report the detailed investigation results of Gangcha (GC) and Reshui (RS) sections, located at the northern Qinghai Lake area. The chemical index of alteration (CIA) and Al2O3–(CaO*+Na2O)–K2O (A−CN–K) ternary diagram suggest that most of the sediments experienced the degree of weak and moderate chemical weathering. The study area had undergone the great alternation between wet and dry climate, reflected by the variation of CIA values. The accumulation hiatus in the palaeosol layer was identified in the RS section. Our comprehensive results indicate that the relatively dry climate conditions and strong aeolian activity occurred from 11.0 to 7.5 ka in the Qinghai Lake area, in agreement with widespread aeolian sand deposits and loess deposits in the investigated aeolian sections. The middle Holocene (from 7.5 to 3.0 ka) was characterized by humid climate conditions and weak aeolian activity, supported by commonly developed palaeosol deposits in the Qinghai Lake area. After 3.0 ka, the aeolian activity was again strengthened due to drier climate conditions. The variations of summer insolation and the Asian monsoon may cause the increase or decrease of effective moisture, thereby result in the climate changes between dry and wet in the Qinghai Lake area.

Loess is prone to collapse upon wetting due to its open metastable structure, which poses a considerable threat to the environment, construction processes and human life. In this study, double oedometer tests and scanning electron microscopy and mercury intrusion porosimetry analyses were conducted on loess from Yan’an to study the macroscopic and microscopic characteristics of loess wetting deformation and the underlying mechanism. The wetting collapse of loess under loading depends on the changes in different microstructure levels and elements. This collapse chain reaction is manifested by the dissipation, scattering and recombination of the cementation, deformation and reorganization of the particles, blocking of the pore channels, decrease in the dominant size and volume of unstable macropores (>14 µm) and abundant mesopores (2.5–14 µm), increase in the volume of small pores (0.05–2.5 µm), and volume contraction at the macroscale. This process is dependent on the initial water content, stress level and wetting degree. These findings can facilitate collapsible loess hazard prevention and geological engineering construction.

The aeolian loess-paleosol sequences in the Chinese Loess Plateau (CLP) are an excellent archive of variations in atmospheric circulation in the geological past. However, there is no consensus regarding the roles of the East Asian winter monsoon and westerly winds in transporting the dust responsible for loess deposition during glacial and interstadial periods. We conducted detailed measurements of the anisotropy of magnetic susceptibility (AMS) on two parallel loess profiles covering the most recent 130 ka in the western CLP to determine paleowind directions. Results show that the magnetic lineations of the loess and paleosol units in both sections are significantly clustered along the northwest to southeast direction. These observations demonstrate that the prevailing wind system responsible for dust transport in the western CLP was the northwesterly winter monsoon, rather than the westerly winds. The AMS-derived dust-bearing wind direction was relatively stable during the last glacial and interglacial cycle in the western CLP, consistent with sedimentary and AMS evidence from the eastern CLP. Accordingly, it is reasonable to conclude that large areas of deserts and Gobi deserts areas located in the upwind direction were the dominant sources for the aeolian deposits of the Loess Plateau.

Loess sequences provide some of the most important continental records of climatic change, and various pedogenesis proxies from Chinese loess deposits have provided humidity records for the Miocene through Holocene. Amongst these proxies, magnetic properties have often been used to reconstruct paleoprecipitation; however, an increasing number of studies have recognized that magnetic records from loess deposits are also influenced by temperature and hence they can be used to reconstruct paleotemperatures. In the present study, the magnetic characteristics of modern loessic soils and loessic paleosols from five regions spanning a broad climatic gradient were studied to investigate the temperature dependence of the pedogenic production of magnetic minerals. The results indicate that the magnetic characteristics are dependent on the temperature of particularly season, rather than mean annual temperature in temperate region. The findings can potentially provide insights into changes in climatic seasonality on geological timescales.

Paleoclimatic reconstruction is critical for understanding present-day climate and for testing models that are currently used to predict future climatic changes. Different climatic conditions produce different clay minerals that can be recorded in geological archives providing insights into past weathering scenarios. However, in southern South America, scarce information is available from clay mineral assemblages found in aeolian sediments, such as loess deposits. Moreover, there is a lack of studies employing clay minerals for paleoclimatic reconstruction at dust sources and loess deposits. Therefore, this work explores clay mineral composition of modern dust source areas in southern South America and in the pampean loess records to gain insight into paleoenvironmental conditions prevailing during the late Pleistocene-early Holocene in the region. Clay minerals recovered from the loess deposits are of an allochthonous origin, implying their formation at the ‘arid diagonal’, then blown away, and deposited downwind in the Pampas without post-depositional changes. Clay mineral assemblages indicate that these minerals and rare earth elements (REE) analyzed in two loess sections of the Pampean Plain helped to reconstruct past climatic scenarios in the dust source areas during the transition from the last glacial to the current interglacial period. Furthermore, our work contributes to the assessment of the strengthening/weakening of the different South American dust sources in light of recent published geochemical and textural evidence.

Loess-paleosol bluffs can be unstable, but in the course of urbanization, houses may be built in such locations to take advantage of the view. One factor affecting the stability of such bluffs is water, the role of which in mass movements is well established. In this study, the connection of mass movements to meteorological conditions, such as rainfall and subsequent water level changes, was researched using new statistical methods. The periodicity of the water level of the Danube was analyzed using wavelet spectrum analyses, while changepoint analysis was used to determine variations in the quantity of precipitation. These results were compared to the chronology of six mass movements in Kulcs, Hungary. This study also focused on the changes in geochemical properties of loess in different weather conditions (dry periods, wet periods, and flooding). The results showed that only two mass movements were connected to hydrological conditions, and in the other case human activity and geochemical changes may have been factors. The results of geochemical models created using PHREEQC showed calcite and kaolinite precipitation, and albite and dolomite dissolution as the main mineral changes over the course of a year. Albite was found to dissolve only in wet periods, and kaolinite precipitation was significant during flood periods.

In the Loess Plateau in Northern China, repeated freeze-thaw (FT) cycles deteriorate the strength and structure of loess as a foundation soil, resulting in the instability or failure of supporting structure. Lignosulfonate is an eco-material, utilized as an effective and nontraditional stabilizer to improve the engineering properties of metastable soils. A series of laboratory tests, including unconfined compression tests, cyclic loading-unloading tests and scanning electron microscopy, on calcium lignosulfonate (CL)- and sodium lignosulfonate (SL)-stabilized loess were performed to investigate the stabilization effect, deterioration mechanisms of the FT cycles, and the resistance to FT cycles. Two traditional stabilizers, quicklime (QL) and sodium silicate (SS), were selected, and the engineering properties of QL- and SS-stabilized loess were compared with those of CL- and SL-stabilized loess. The results showed that the strength values of CL- and SL-stabilized loess specimens decreased by 34.2% and 50% respectively, after 20 FT cycles, whereas those of the traditionally SS- and QL- stabilized specimens decreased by 85.3% and 82.87%, respectively. The elastic moduli of SL- and QL-stabilized loess specimens decreased by 22.1% and 92.0%, respectively. The mean energy dissipations of nontraditionally treated specimens also decreased significantly less than those of traditionally treated specimens. Overall, the results showed CL and SL had better stabilization effects on engineering properties of loess than QL and SS, and their stabilized loess specimens exhibited stronger resistance to FT cycles. The study findings demonstrated the significant potential of lignosulfonate for extensive application in cold loess areas.

Paleoenvironmental reconstructions are commonly based on isotopic signatures of a variety of carbonate types, including rhizoliths and land-snail shells, present in paleosol-loess sequences. However, various carbonate types are formed through distinct biotic and abiotic processes over various periods, and therefore may record diverging environmental information in the same sedimentological layer. Here, we investigate the effects of carbonate type on δ13C, δ18O, and clumped isotope-derived paleotemperature [T(Δ47)] from the Quaternary Nussloch paleosol-loess sequence (Rhine Valley, SW Germany). δ13C, δ18O, and T(Δ47) values of co-occurring rhizoliths (-8.2‰ to -5.8‰, -6.1‰ to -5.9‰, 12–32°C, respectively), loess dolls (-7.0‰, -5.6‰, 23°C), land-snail shells (-8.1‰ to -3.2‰, -4.0‰ to -2.2‰, 12–38°C), earthworm biospheroliths (-11‰, -4.7‰, 8°C), and “bulk” carbonates (-1.9‰ to -0.5‰, -5.6‰ to -5.3‰, 78–120°C) from three sediment layers depend systematically on the carbonate type, admixture from geogenic carbonate, and the duration of formation periods. Based on these findings, we provide a comprehensive summary for the application of the three isotopic proxies of δ13C, δ18O, and Δ47in biogenic and pedogenic carbonates present in the same sediment layer to reconstruct paleoenvironments (e.g., local vegetation, evaporative conditions, and temperature). We conclude that bulk carbonates in Nussloch loess should be excluded from paleoenvironmental reconstructions. Instead, pedogenic and biogenic carbonates should be used to provide context for interpreting the isotopic signature for detailed site- and time-specific paleoenvironmental information.

This paper describes an assemblage of diverse floodplain facies of reworked loess (facies b, c) in a Middle Pleistocene monsoonal setting of the Hanzhong Basin, central China. The vertical and lateral sedimentary sequences show changing energy conditions. Apart from the highest energy in the channel facies (facies a), a relatively high energy floodplain environment (facies b) prevailed in waterlogged conditions, with small, laterally migrating (sub)channels. Facies b generally interfingers with aggrading horizontal sheets of overbank deposits in alluvial pools and swamps in a floodplain with much lower energy (facies c), in which phases of stability (soil formation) occasionally interrupted overbank deposition. Reworked loess forms the main part of the floodplain deposits. The paleosols are considered to have been formed under low hydrodynamic conditions in an interglacial environment. These interglacial conditions follow the commonly assumed glacial conditions of channel facies a. The sedimentary successions in the floodplain show a recurrent composition and cyclicity between wet and dry floodplain sedimentation terminated by stability with soil formation. The cyclic rhythm of stacked high- and low-energy floodplain sediments is attributed to varied intensity of different hydrodynamic flooding events that may have been due to changing monsoonal rainfall or simple intrinsic fluvial behavior.

Purpose: Loess in Northern Italy has been usually considered deposited during the MIS 4-2 period, which corresponds to the last Pleistocene glacial cycle. In particular, no absolute dating evidenced loess depositions older than ca. 89 ka. We investigated two strongly rubified soil profiles in the southern margin of the Alpine range in Lombardy to prove their aeolian origin and age of formation. Methods: We analysed the granulometry of all genetic horizons of these strongly rubified soils, and a total of 8 samples were collected for luminescence dating purpose. Results: Most of the analysed soil horizons were dominated by silt and were characterized by the s-shaped granulometric curve, typical of loess materials. A particularly high clay content evidenced a strong weathering degree. A deep horizon was particularly clay rich, and it was interpreted as a typical Terra-Rossa horizon. Luminescence dates increased with depth, reaching 122 ka for the deepest loess layer and 453 ka (minimum age) for the Terra-Rossa horizon. Conclusions: The deepest observed loess layer represents the oldest quantitatively dated aeolian deposition in Northern Italy up to now.