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Aeolian sediments and landforms of the former continental ice sheets' periphery can be used as invaluable sources of information on palaeoenvironmental changes. In the Northeastern Europe, there is very limited knowledge on the structure and age of the aeolian deposits and landforms. This study presents the first data on distribution and chronology of aeolian sediments and landforms in the Vychegda River basin (northeast of the East European Plain). Using grain-size analysis, radiocarbon and OSL dating, we were able to determine the age of the sediments found in the region and study their lithological composition. We discovered aeolian sediments comprising the upper parts of the most river terraces throughout the valley; they come in forms of dunes, dune fields, and sandy or loess-like covers. Previously it was argued that the terraces' upper parts were comprised by glaciolacustrine deposits, but lithological composition of these sediments showed their aeolian origin. It was found that most of the aeolian sediments have formed in the Late Glacial, between 17 and 10.5 ka. We consider that increased fluvial activity and melting of permafrost were the main causes of the aeolian processes activization and that sediment availability was the most important controlling factor during that time. [ABSTRACT FROM AUTHOR]

In order to identify the sedimentary processes, depositional environment, and provenance, the study used sieving and SEM-EDS to analyze the particle size and quartz grain microtextures from sediments in the central part of the Gulf of Guinea. Samples were collected from three locations (Yoyo, Mbiako, Mouanko) for grain size analysis and particle size parameters such as mean, sorting, skewness, and kurtosis were determined. In general, the sediments are dominated by medium-grained sands (81.14%). The descriptive statistics and bivariate relationship plots of different particle size parameters show that the sediments are medium to fine, moderately well classified, fine-to-very fine skewed towards fine with platykurtic. Most of the sands come from a river-type environment, as well as beaches, and transported by saltation. The transport mode of the fine sands is dominated by suspension transport. Rolling is the dominant mode of transport for coarse sands. Twenty-five features were known and clustered according to their types of origin. Among them, eighteen features characterize the mechanical origin, four belong to the chemical origin, and three represents mechanical/chemical origin. Quartz microtextures show that the mechanical, mechanical/chemical, and chemical are mostly associated with fluvial, littoral, and aeolian processes. The quartz grains in the sediments from the central part of the Gulf of Guinea are resulting mostly from crystalline source rocks. Furthermore, shapes (angular, subangular, sub-rounded) indicate that these sediments were transported by a medium to high-energy environment, short transport or quick deposition. Moreover, occurrence of sub-rounded grains militated for far-source materials. [ABSTRACT FROM AUTHOR]

Beach placer gold has been mined around the world historically, but extraction of fine (~ 100 µm) gold particles is notoriously difficult. This study illustrates morphological and mineralogical changes that transform fine gold during aeolian processes on windy beaches and contribute to mine concentration inefficiencies. Sandblasting on exposed beaches in southern New Zealand has caused extreme attenuation of edges of gold flakes that were previously transported in rivers for > 200 km. Flakes have been transformed into complex but compact toroids and spheroids with thin (~ 20 µm) internal and external strands of attenuated gold. Most of the gold within the attenuated strands has recrystallised to fine (micron-scale) undeformed grains with little or no Ag (< 1 wt%). Some coarse (> 40 µm) gold grains remain from the precursor fluvial particles, and these retain original Ag contents (1–10 wt%). These coarse grains show substantial internal crystallographic deformation and sub-grain formation, although some of these strain effects may have been inherited from fluvial transport. Co-existing detrital platinum minerals are much less malleable than gold during sandblasting and have only minor (10-µm scale) toroidal deformation on edges of fluvial flakes. The complex frameworks of the fine toroidal and spheroidal gold particles can include air, water, and clay, which lowers their average density and so they commonly float on water and are readily entrained with other heavy minerals. The fine particle size, compact shapes, and clay coatings also resist mercury amalgamation. [ABSTRACT FROM AUTHOR]

Pasture loads are one of the key anthropogenic factors in the dynamics of the state of vegetation and soil cover of arid landscapes. The purpose of this study is to establish the spatial distribution of pasture loads in the Chyornye Zemli region using remote sensing data from space, geoinformation technologies, and statistical data. Mapping of livestock farms, sheepfolds, and other places of concentration of livestock for 1984–1986 and 2020 is carried out in this work. Both periods are characterized by a surge in desertification processes and a sharp increase in the areas of open sands and deflated lands. The areas of pastures with different loads during cattle grazing are established; patterns of spatial distribution of mobile sands depending on soil-forming rocks and distance from livestock farms are also determined. In recent years, compared with 1984–1986, the density of farms on sandy soils has increased, which has led to overgrazing, the destruction of vegetation, and the activation of Aeolian processes. Approximately 80% of pastures exceeded the permissible grazing standards, and 90% of pastures are located in a 3-km zone around the places of concentration of livestock. The results can be used to regulate pasture loads in the region to prevent the desertification of landscapes. [ABSTRACT FROM AUTHOR]

Summary: Shrub encroachment is a common ecological state transition in global drylands and has myriad adverse effects on grasslands and the services they provide. This physiognomic shift is often ascribed to changes in climate (e.g. precipitation) and disturbance regimes (e.g. grazing and fire), but this remains debated. Aeolian processes are known to impact resource distribution in drylands, but their potential role in grassland‐to‐shrubland state changes has received little attention.We quantified the effects of 'sandblasting' (abrasive damage by wind‐blown soil) on the ecophysiology of dryland grass vs shrub functional types using a portable wind tunnel to test the hypothesis that grasses would be more susceptible to sandblasting than shrubs and, thus, reinforce transitions to shrub dominance in wind‐erodible grasslands when climate‐ or disturbance‐induced reductions in ground cover occur.Grasses and shrubs responded differently to sandblasting, wherein water‐use efficiency declined substantially in grasses, but only slightly in shrubs, owing to grasses having greater increases in day/nighttime leaf conductance and transpiration.The differential ecophysiological response to sandblasting exhibited by grass and shrub functional types could consequently alter the vegetation dynamics in dryland grasslands in favour of the xerophytic shrubs. Sandblasting could thus be an overlooked driver of shrub encroachment in wind‐erodible grasslands. [ABSTRACT FROM AUTHOR]

The results of a comprehensive study of the Upper Cenozoic Ulan-Zhalga reference section in western Transbaikalia are presented. The paleontological, paleomagnetic and petromagnetic, lithological-mineralogical, and geochemical data obtained allowed us to identify and characterize the Lower, Middle, and Upper Pleistocene and Holocene deposits in the section and to reveal the features and conditions of sedimentation. Five members recognized in the section are combined into two sequences: the lower (Beds 1–27, units 1–3) and the upper (Beds 28–35, units 4–5). The boundary between Matuyama and Brunhes chrons (0.773 Ma) is determined at a depth of 15 m and the upper boundary of the Jaramillo subchron (0.990 Ma) is determined at a depth of 23 m. The Matuyama/Brunhes boundary coincides with the boundary of Lower and Middle Pleistocene faunal assemblages. The formation of the section corresponds to two major stages of sedimentation with the boundary between the units 3 and 4 (depth of 11.8 m). Changes in rock magnetic and grain size parameters through the section has a climatic nature and reflects environmental changes. The formation of the lower part of the section (unit 1), which was accompanied by active soil formation, is characterized by the most heat- and moisture-enriched conditions. The upper sequence of the section accumulated under colder and drier conditions with increased dynamics of aeolian processes. [ABSTRACT FROM AUTHOR]

Located at the modern junction of the Asian Summer Monsoon and the Westerlies, the northeastern Tibetan Plateau and western Chinese Loess Plateau are in distinct climatic setting from the middle and eastern Chinese Loess Plateau. Besides, Holocene climate variations near the Asian Summer Monsoon margin are highly debated with different models proposed. We carried out environmental magnetic analyses on the Minle loess section, with continuous deposition between 13.3–0.5 ka, located near this margin. Results show that the magnetic susceptibilities of palaeosols are dominantly contributed by superparamagnetic (SP) and single-domain (SD) maghemite and/or magnetite produced by pedogenesis. Limited changes in the content of haematite indicate that dust origin hardly influenced the magnetic mineral variations. The section is divided into four substages according to the changes in magnetic indices and provides a full scene of Holocene climatic evolutions. During the coldest and driest Late Glacial (13.3–11.7 ka), it displays the weakest pedogenesis, as suggested by the lowest SP and SD concentration. The strongest pedogenesis in the Minle section produced higher magnetic susceptibility than the loess records in the Chinese Loess Plateau during the early Holocene Optimum (11.7–8.1 ka). The subsequently declined summer insolation, equatorward migrated Westerlies and the weakened Asian Summer Monsoon led to weak pedogenesis during the middle Holocene (8.1–5.3 ka). Stronger pedogenesis during the late Holocene (5.3–0.5 ka) than the middle Holocene might be due to lower evapotranspiration from weaker insolation and/or to the enhanced winter Westerlies. We attribute the spatiotemporal differences in climatic records of the Chinese loess to precipitation, effective humidity and aeolian geomorphological processes. [ABSTRACT FROM AUTHOR]

The aeolian activity in central Asia (CA)and its relevant dust emissions significantly influenced the global climate changes and biogeochemical cycles. Fully understanding the formation processes and mechanism of aeolian activity in CA is helpful to elevate our knowledge of global climate change, materials cycles and aeolian disasters monitoring and prevention. However, this issue is still controversial at present. We systematically review and integrate the geological archives and instrumental data to trace the variations of aeolian activity on sub-orbital, centennial, and decadal timescales in CA, and assessed the relationship between aeolian activity changes and climate changes, atmospheric circulation system changes and human activities. The result suggested that on the sub-orbital scale, during the past 8500 years, the low intensity and relatively stable aeolian activity occurred during the early to middle Holocene (8500-4000 Cal. Yr B.P.), followed by a more intensive/frequent and more variable aeolian activity conditions during late Holocene (4000-0 Cal. Yr B.P.). On centennial scale, over the past 1000 years, the more intensive (attenuated)aeolian activity occurred during the Little Ice Age (Medieval Warm Period). On the decadal scale, during the last century, aeolian activity in CA has decreased greatly since the 1960s, accompanied by the increasing of temperature and precipitation. Compared to the changes of climate, atmospheric circulation system and human activities, we proposed that the Siberian High (SH) which related to the temperature variations, rather than the precipitation and human activity, largely controlled aeolian activity in CA on the sub-orbital, centennial, and decadal timescales. Cooling at high latitudes markedly enhances the intensity of the SH, which is displaced southward as a result, causing the incursion of cold air masses from high latitudes which result in more robust wind regimes that provide suitable wind regimes for dust emission the study area. [ABSTRACT FROM AUTHOR]

The results of study of the composition of Quaternary subaerial slope sediments of the new Ulan-Zhalga reference section, 30 m thick (West Transbaikalia), using X-ray diffratometry (XRD), IR spectroscopy, laser granulometry, and elemental analysis are presented. The sediments contain quartz, feldspars, clay minerals, carbonates, hematite, and traces of amphibole. It is shown for the first time for the subaerial section that the composition and structure of carbonates indicate climate changes in the Pleistocene and Holocene. The correct identification and determination of the amount of carbonates is based on modeling of their XRD patterns using the Pearson VII function. The sections host two thick units of subaerial sediments with different lithological–mineralogical characteristics, which correspond to two large sedimentation stages. The lower unit formed under moderate wind activity and relatively high moisture, which is evident from a wide occurrence of soil horizons and the presence of low-Mg carbonates. The upper unit, which formed in colder and drier conditions with a higher dynamic of aeolian processes, contains calcite, high-Mg calcite, and excess-Ca dolomite. [ABSTRACT FROM AUTHOR]

The Hormuz Strait and Makran coastal plains in southeast Iran are significant sources of dust storms in south Asia due to an arid climate with a strong wind regime, low topography, poor vegetation cover, and large watersheds with available loose fine-grained sediments. However, their sedimentology, mineralogy, and geomorphic landforms are poorly studied. Granulometry and mineralogy analyses are performed on 46 samples of the coastal plains to explore the influence of aeolian and fluvial processes on the surface sediment properties of the coastal plains. The geomorphic landforms are mapped based on field observations, geological-geomorphological maps, and satellite images. The results show that the main sources of fine-grained dust are distal alluvial fans and flood plains, supratidal plains, and badlands. Calcite, quartz, and feldspar are major, and dolomite and halite are minor minerals. Calcite displays a positive relationship with grain size and eastward subtractive distribution pattern, while quartz exhibits a negative correlation with grain size and eastward additive distribution pattern. Feldspar shows almost a scatter distribution. The monotonous distribution pattern of chlorite, illite, and kaolinite as the main clay minerals is controlled by fluvial and alluvial processes. Aeolian processes influenced the eastward subtractive distribution of montmorillonite and palygorskite as minor clay minerals. The surface sediment texture and mineralogy of the Hormuz Strait coast are strongly affected by northwesterly wind and dust storms. Aeolian processes are dominated on the western Makran coast with large terrestrial and coastal sand dunes, while fluvial and alluvial processes are dominant on the eastern Makran coast with large distal alluvial fans. [ABSTRACT FROM AUTHOR]

India witnessed a massive tsunami on 26th of December 2004, which adversely affected the East coast of India. This research focuses on the coastline between Nagoor to Poompuhar, Tamil Nadu which lies for a stretch of 35 km. Eight stations, namely, Poompuhar, Chinnangudi, Kuttyandiyur, Chandrapadi, Kottucherimedu, Karaikal Beach, Vadakku Vanjiyur North, and Nagoor Beach were chosen and a total of 73 samples were studied. The motive is to study the characteristics of pre and post tsunami sediment samples by analysing their grain size. The statistics of the sediments were done using G2Sd package of R programme, which showed lowering in the mean values of phi, percentage of increase in bimodality, change in skewness, and moderately well sorted sediments post tsunami indicating high-energy circumstances. The bivariate plots were plotted between different parameters to get more insight about depositional environments. Linear Discriminate Functions reveal the samples of pre-tsunami were deposited by aeolian process but most of the post-tsunami samples were deposited by beach process and 100% are from shallow marine conditions. The CM pattern and tractive current plots reveal the gradual suspension in pre tsunami whereas rolling in post tsunami. The characteristics of sediments of pre- and posttsunami in a more effective manner are presented in this paper. [ABSTRACT FROM AUTHOR]

This research presents a classification and analysis of the spatial distribution of Holocene aeolian landforms on the White Sea Coast. The authors have identified five types of secondary dunes based on interpretation of detailed satellite images and topographic charts, as well as analysis of literature sources: foredune plains and beach ridge plains, cliff-top dunes, blowouts and parabolic dunes, transgressive dunefields, and sand sheets. The dunes formed mainly since the Middle–Late Holocene. They are confined to sandy coasts, where postglacial uplift rates did not exceed ~3 mm/year during the Middle–Late Holocene. The coastal dunes were formed in connection with sediments that entered the coastal zone with solid river runoff and from selective erosion of glacial sediments. The rhythmic patterns of the activation of aeolian processes in different parts of the White Sea Coast were asynchronous. [ABSTRACT FROM AUTHOR]

Crete is located in the collision zone of tectonic plates; therefore, the island coast was often shaped due to tectonic phenomena. In 365 AD, a major earthquake caused the uplift of the coast of western Crete by a few metres. It means that the modern beaches of this part of the island are fragments of the former seabed with its littoral deposits. Some of these deposits are affected by wind activity. The article aims to answer the question, did wind transport lasting more than 1600 years give the marine deposits the features of aeolian deposits? Grain size and mineral composition were determined for samples from seven research sites in western Crete. Deposits representing three sedimentary environments were examined – high-energy beach, aeolian, and beach with permanent or periodic fluvial supply. Quartz abrasion was established using the morphoscopic method. In the 0.8–1.0 mm fraction, less resistant carbonate minerals dominate (on average, 77%), while the content of more resistant quartz is low (on average, 18%). It means most deposits are relatively young and were briefly in the range of aeolian processes. Coastal deposits are dominated by moderately rounded and mat grains EM/RM, on average 79%. The content of very well-rounded and mat grains RM is low, on average 18%. Multiple predominances of EM/RM grains in relation to RM grains indicate short-term aeolian transport. It can be concluded that the degree of aeolisation of coastal deposits by wind activity from 365 AD to the present is weak, at most moderate. [ABSTRACT FROM AUTHOR]

The deposits of Sydney's rivers are thought to have experienced widespread aeolian modification during the Quaternary. The resultant sediments form archaeologically important landscapes upon which are found several of the oldest archaeological sites in the Sydney district. Unfortunately, little is known of the processes and products of aeolian reworking. The context of the archaeological discoveries is therefore enigmatic. This study focusses on the Agnes Banks Sand, a Cenozoic sand body that may represent the only sedimentary unit in the Sydney area that preserves reliable evidence of the action of aeolian processes on fluvial sediments. Our work confirms that the sands are indistinguishable from inland dune deposits worldwide, with the deposits reworked from alluvial sediments within and adjacent to the channel of the nearby Nepean River. The sands form east–west-aligned linear dunes, whilst the sediment body fines to the east, a pattern consistent with entrainment by westerly winds. Three other aeolian depositional bodies have been identified alongside the Hawkesbury–Nepean River. Together, these form an assemblage of source-bordering dunes that lies downwind of the river across the northern part of the Cumberland Basin. Deposition here began in Marine Isotope Stages 3–2 and continued into Marine Isotope Stage 1, a period corresponding with a general episode of dune activation across southeast Australia. Although it is widely believed that the Agnes Banks Sand was formed sometime between the Pliocene and the Middle Pleistocene, we present evidence that its deposition post-dates 65 ka and that the deposits are contemporaneous with the other fluvio-aeolian units in the catchment. The true importance of Agnes Banks, however, is as a type locality from which it has been possible to derive sedimentological and geomorphological signatures that may be applied to appraisals of the fluvio-aeolian record within (and perhaps beyond) the Sydney area. [ABSTRACT FROM AUTHOR]

The Samalayuca Dunes (SMD) (Médanos de Samalayuca), Chihuahua, México, are one of México's largest and least studied dune fields, now managed as a Protected Area for their ecological characteristics. We present a morphometric characterization of the dune field based on remote sensing and field studies, to advance under standing of its physical environment. SMD's generally-fine sands originate from shoreline deposits of Paleolake Palomas, transported eastward (downwind) along an aeolian corridor, accumulating primarily as echo dunes upwind of the sierras of Samalayuca and Presidio. A complex wind regime, with northerly and southerly winds complementing regionally-prevailing southwesterlies, modified by topographic effects, shapes the SMD's morphology. The sand sea covers ~139.7 km2, with ~113.8 km2 in the main eastern body and ~25.9 km2 in a northwester n subfield. We describe six major dune for ms: north to south straight-crested dunes, east to west straight-crested dunes, star dunes, vegetated parabolic dunes, relict transverse dunes, and "megastar" (draa) dunes. Mean interdune centroid spacing is 76.5 m. The active dunes, previously described as an "aklé" pattern, are predominantly straight-crested dune sets oriented near-perpendicular to each other with general north-south and east-west crest orientations, 4-5 m high, spaced ~67 m apart for north-south trending crests and ~53 m for east-west trending crests, representing a nearly perpendicular interference pattern in some locations. The active dunes are superimposed in a compound and complex arrangement on relict remnants of much larger north-northwest trending transverse dune ridges fanning out from south to north-northwest, spaced approximately ~1 km apart and ~50 m high. The easternmost dune ridge contains an active set of at least 15 active megastar and reversing dunes up to 120 m tall, increasing in size and complexity from south to north. As a protected area with historical and ecological value, additional geologic investigations should be performed at the SMD, to help conserve this remarkable geologic feature. [ABSTRACT FROM AUTHOR]

The White River Badlands (WRB) of South Dakota record eolian activity spanning the late Pleistocene through the latest Holocene (21 ka to modern), reflecting the effects of the last glacial period and Holocene climate fluctuations (Holocene Thermal Maximum, Medieval Climate Anomaly, and Little Ice Age). The WRB dune fields are important paleoclimate indicators in an area of the Great Plains with few climate proxies. The goal of this study is to use 1 m/pixel-resolution digital elevation models from drone imagery to distinguish Early to Middle Holocene parabolic dunes from Late Holocene parabolic dunes. Results indicate that relative ages of dunes are distinguished by slope and roughness (terrain ruggedness index). Morphological differences are attributed to postdepositional wind erosion, soil formation, and mass wasting. Early to Middle Holocene and Late Holocene paleowind directions, 324°± 13.1° (N = 7) and 323° ± 3.0° (N = 19), respectively, are similar to the modern wind regime. Results suggest significant landscape resilience to wind erosion, which resulted in preservation of a mosaic of Early and Late Holocene parabolic dunes. Quantification of dune characteristics will help refine the chronology of eolian activity in the WRB, provide insight into drought-driven landscape evolution, and integrate WRB eolian activity in a regional paleoenvironmental context. [ABSTRACT FROM AUTHOR]

The late-glacial and post-glacial history of the development of the White Sea coastal zone in the area of the Varzuga River estuary is considered as a result of the interaction of endogenous and exogenous factors of coastal morpholithogenesis. Based on the geomorphological investigations, study of Holocene deposits by lithostratigraphic, diatom, and radiocarbon analyses, as well as collection and analysis of published data, new results on the development of relief of the area for ~13 cal ka have been obtained. The features of the regional hierarchical morphostructure and local post-glacial tectonics of the territory—the spatial relationships of blocks and the rate of vertical movements—were determined. The superimposed linear Nizhnevarzugskaya Depression, which determined the configuration of the Varzuga River estuary in the late-glacial and post-glacial periods, was identified for the first time. The influence of the spatial ratio of blocks and differentiated post-glacial uplift on the coastal morpholithogenesis was established. The course of changes in the relative sea level (RSL), development conditions, and morphodynamics of the open coast and the estuary of the Varzuga River were reconstructed, and new data on the rhythms of coastal geomorphologic processes (coastal, estuarine, and eolian) were obtained. Three stages of development of the coastal zone were identified, which corresponded to regional rhythms of changes in the relative sea level and climate. They are (I) the Late Glacial transgression and Early Holocene regression (~12 to 9.8 cal ka BP), (II) the Middle Holocene Tapes transgression (7.8 to 4.9 cal ka BP), and (III) the Late Holocene regression (after 4.9 cal ka BP). The upper marine boundary of the Late Glacial transgression was traced at heights of ~54 or 55 m to the west of the Nizhnevarzugskaya depression, 39 or 40 m to its east, and 22 to 25 m a.s.l in the depression. The shores of lower morphostructural blocks up to ~10.2–9.8 cal ka BP were probably blocked by dead ice. During the Tapes transgression, the RSL reached a maximum (~20 m a.s.l.) of ~7.8 to 7.6 cal ka BP and slowly decreased to ~15 m a.s.l. in the interval of ~7.6 to 4.9 cal ka BP. The prevailing directions of sediment fluxes and the approaches of winds and waves became similar to those of today and have not changed significantly since that time. The main source of the coastal sediment supply was the erosion of glaciofluvial sediments and the input of sands from the seabed. In the interval of ~4.9 to 1.7 cal ka BP, the RSL decreased to ~5 m a.s.l. and then slowly approached the modern one. Activation of coastal (~5–1 cal ka BP) and channel (~4.9–4.7 to 3.6–3.4 cal ka BP) processes contributed to rapid filling of the estuary and formation of accumulative sand terraces on exposed banks. The sediment runoff of the Varzuga River became the main source of coastal sediment supply. After ~2.3 cal ka BP, several stages in the intensification of eolian processes were revealed. [ABSTRACT FROM AUTHOR]

The effects of biochar on soil improvement have been widely confirmed, but its influence on soil microorganisms is still unclear. Elucidating the complex relationship and the community assembly processes of microorganisms under biochar addition is important to understand the ecological effects of this substance. We performed a one-time addition of biochar on aeolian soils and planted maize (Zea mays L.) continuously for 7 years. Afterwards, soil samples were collected, and the 16S/ITS rRNA gene sequencing technology was used to study changes in microbial community structure, network characteristics, and community assembly processes in the aeolian soils. We found that biochar addition significantly increased the maize yield and changed the soil microbial community composition (β-diversity), but had no significant effect on the microbial α-diversity. The addition of 31.5–126.0 Mg ha−1 of biochar led to a reduction of the rhizosphere bacterial network's edge number, average degree, and robustness, but had no significant effect on the fungal network properties. The bacterial community was controlled by deterministic processes, while fungi were mainly controlled by stochastic processes. The addition of 126.0 Mg ha−1 of biochar led to a transformation of the bacterial community's assembly processes from deterministic to stochastic. These results indicate that the stability of the rhizosphere bacterial community's complex network in aeolian soils diminishes under biochar addition, together changed the bacterial community's assembly processes. Fungi can instead effectively resist the environmental changes brought by biochar addition, and their network remains unchanged. These findings help clarify the effect of biochar addition on microbial interaction and assembly processes in aeolian soils characteristic of arid regions. Key points: • Biochar addition led to changes in the microbial community composition • Biochar addition reduced the network's stability of rhizosphere bacteria • Biochar addition changed the processes of the bacterial community assembly [ABSTRACT FROM AUTHOR]

Intense aeolian processes in arid and semi-arid environments play an essential role in the preservation and destruction of archeological sites. This is especially the case in the lower basin of the Colorado River at the eastern Pampa-Patagonia Transition of Argentina, as is illustrated by geoarchaeological and chronostratigraphic studies at a mid-Holocene hunter-gatherer site, La Modesta, where aeolian processes strongly influence the archeological record in dune sediments. At La Modesta, surface archaeological materials are numerous and well preserved, although the stratigraphic record is incomplete. Optically stimulated luminescence (OSL) dating of sediments that contain cultural material provides a chronology dating from ca. 8.2 ka but shows one or more hiatuses from ca. 6–2 ka in the sedimentary succession. Intense morphogenesis related to arid climates likely caused gaps in sedimentation, affecting the integrity and resolution of the archaeological record. This study helps explain mid-Holocene archaeological discontinuities throughout central Argentina and highlights the importance of considering taphonomic and geologic biases when dealing with the absence or reduction of the archaeological record in dryland regions. [ABSTRACT FROM AUTHOR]

Throughout Earth's history, dust deposits have been considered sensitive markers of fluctuations in global atmospheric circulation patterns. However, the identification of ancient dust deposits remains problematic, as their massive (structureless) nature impedes an unequivocal classification. In southern Africa, the Lower Jurassic Clarens Formation is dominated by intriguing structureless sandy siltstones that have been interpreted as loess even though classical diagnostic outcrop‐scale loess features are not observed. In this study, we utilized grain characteristics such as size, shape, sorting and fabric to assess the origin of these ubiquitous massive beds, as compared to strata with a known origin in the unit. Based on these grain characteristics, the massive beds can be grouped into six different facies types (Facies 1–6). Facies 1 has very similar grain features to the large‐scale cross‐bedded strata and thus it is interpreted as migrating dune deposits, only apparently massive. The dominant grain size with a large proportion of very fine‐grained sand and the random grain fabric suggests that Facies 2 resulted from sandy dust fall (short‐term suspension), whereas Facies 3 is interpreted as aeolian dust, having features consistent with modern and ancient loess due to its dominant silt grain size and random grain fabric. Features in Facies 4 are undiagnostic and could reflect a range of aeolian processes, although a dominant silt grain size may suggest an overwhelming loess component. Facies 5 and 6 show primary aeolian signatures with the preferred grain orientation being evidence of reworking in an aqueous setting (e.g., lake, stream). These six facies types represent a spectrum of depositional processes that occurred in response to erg migration and climatic changes along this Early Jurassic erg margin. Their facies diversity is evidence for: (1) dry and windy conditions in SW Gondwana during the Sinemurian to Pliensbachian, and (2) reworking of the aeolian sediments in various fluvial and lacustrine settings during the development of one of the largest known sand seas in Earth's history. [ABSTRACT FROM AUTHOR]

The Llano Uplift in central Texas, USA, exposes the southernmost expanse of Laurentian crystalline basement in North America and the overlying lower Paleozoic strata deposited on the Great Unconformity. Systematic detrital zircon (DZ) U-Pb provenance analysis of the Hickory Sandstone--the basal unit of the Cambrian Riley Formation that onlaps the Mesoproterozoic core of the Llano Uplift--yielded locally variable DZ U-Pb signatures with ages ranging from 1800 Ma to 485 Ma (n >1700). The Hickory Sandstone zircons are dominated by 1550-1300 Ma (50%) and 1300-1000 Ma (46%) ages. These two dominant Mesoproterozoic DZ age components likely were sourced from local Grenville metamorphic and igneous basement of the Llano Province (1300-1000 Ma) and from the extra-regional Granite-Rhyolite Province basement to the north and northwest of the Grenville Front, which suggests both local sourcing and a regional drainage system supplying sediment to the southern Laurentian margin during the Cambrian. This interpretation is supported by a minor component of 1800-1600 Ma zircons, sourced from the Yavapai-Mazatzal Province, and zircons with Early Cambrian ages that were likely sourced from the Wichita Igneous Province, which is located to the northwest and to the north of the Llano Uplift, respectively. Documented NNW-trending topographic ridges in the Mesoproterozoic basement surface of the Llano Uplift could have funneled aeolian and fluvial sand supply to the southern Laurentian coast that was reworked in the marginal marine environment. Samples from the western Llano Uplift are dominated by regionally sourced, early Mesoproterozoic Granite-Rhyolite Province DZ ages, whereas samples from the eastern Llano Uplift exhibit a dominant locally sourced Grenville signature. Hickory Sandstone samples also contain a small number of Neoproterozoic (850-600 Ma) and Cambrian (541-487 Ma) zircons. Sources for Neoproterozoic zircons likely were located along the Laurentian continental margins and derived from extension-related magmatism associated with the breakup of Rodinia. Cambrian zircons are most common in Hickory Sandstone samples on the southern and western flanks of the Llano Uplift. Some are reasonably sourced from the Wichita Igneous Province to the north, but the younger Cambrian zircons suggest sources to the west. Upper Hickory strata are dominated (>60%) by 1550-1300 Ma grains with up to 10% >1600 Ma Paleoproterozoic grains. Upper Cambrian sandstones of the Wilberns Formation also contain a significant contribution of >1600 Ma grains, which suggests a possible enlargement of the fluvial headwaters over time extending into older Laurentian provinces to the north and northwest. Differences among DZ populations over relatively limited distances may have been related to NW-oriented ridge and corridor landforms that developed on the Great Unconformity surface, which were products of the Proterozoic tectonic and lithologic architecture affected by aeolian and fluvial processes at this unusual stage in Earth history. Paleocurrent data and atypical detrital grain characteristics for a Hickory Sandstone locality in the southeastern Llano Uplift and its DZ age similarities with Cambrian sandstones of the Argentine Precordillera suggest a common provenance prior to or during Rodinia breakup. [ABSTRACT FROM AUTHOR]

Janus is the Roman god of transitions. In many environments, state transitions are an important part of our understanding of ecological change. These transitions are controlled by the interactions between exogenous forcing factors and stabilizing endogenous feedbacks. Forcing factors and feedbacks are typically considered to consist of different processes. We argue that during extreme events, a process that usually forms part of a stabilizing feedback can behave as a forcing factor. And thus, like Janus, a single process can have two faces. The case explored here pertains to state change in drylands where interactions between wind erosion and vegetation form an important feedback that encourages grass‐to‐shrub state transitions. Wind concentrates soil resources in shrub‐centered fertile islands, removes resources through loss of fines to favor deep‐rooted shrubs, and abrades grasses' photosynthetic tissue, thus further favoring the shrub state that, in turn, experiences greater aeolian transport. This feedback is well documented but the potential of wind to act also as a forcing has yet to be examined. Extreme wind events have the potential to act like other drivers of state change, such as drought and grazing, to directly reduce grass cover. This study examines the responses of a grass‐shrub community after two extreme wind events in 2019 caused severe deflation. We measured grass cover and root exposure due to deflation, in addition to shrub height, grass patch size, and grass greenness along 50‐m transects across a wide range of grass cover. Root exposure was concentrated in the direction of erosive winds during the storms and sites with low grass cover were associated with increased root exposure and reduced greenness. We argue that differences between extreme, rare wind events and frequent, small wind events are significant enough to be differences in kind rather than differences in degree allowing extreme winds to behave as endogenous forcings and common winds to participate in an endogenous stabilizing feedback. Several types of state change in other ecological systems in are contextualized within this framework. [ABSTRACT FROM AUTHOR]

El Valle de la Luna is renowned for its extremely low humidity, including its near lack of precipitation. Northern Chile's El Valle de la Luna, the Valley of the Moon, is a landscape defined by wild geomorphic creations that include badlands, pinnacles, sand dunes, and dry lakebeds. It is sufficient, however, to cause just enough weathering and erosion to create the captivating forms that make El Valle de la Luna so distinctive and memorable. [Extracted from the article]

Despite the wealth of Late Pleistocene archaeology that exists across southern Africa's open landscape, it is routinely neglected in favour of rock shelter (re)excavation, biasing interpretation of human–environment interaction. This is compounded by the scarcity of open-air studies that use geoarchaeological methods to investigate the history and processes involved in their formation. The open-air archaeology of the Doring River Valley is an example of this, despite nearly a decade of dedicated study and publication. Consequently, there remains a limited and untested understanding of the valley's formation history. This paper rectifies this by providing a sedimentary context for the surface archaeology exposed across one of the Doring River Valley's artefact-baring localities, Uitspankraal 7 (UPK7). Characterisation, particle size, mineralogical, morphometric, and geophysical analysis of UPK7′s sand mantle resulted in the identification of four artefact-bearing sedimentary units, the aeolian and pedogenic processes involved in their formation, and their proposed order of deposition. This provides a stratigraphic, taphonomic, and environmental context against which chronometric dating and an analysis of the taphonomic, spatio-temporal, and technological composition of UPK7′s surface archaeology can be compared. This work is the first vital step towards understanding the depositional and behavioural history of a landscape, irrespective of context type. [ABSTRACT FROM AUTHOR]

Many planetary surfaces have been shaped by eolian and fluvial processes, and understanding the resulting landscape is of critical importance to understanding changes in climate. Surface features on Earth and Mars are commonly observed using a variety of remote sensing methods. The observed geomorphology provides evidence of present processes and paleo-processes, but interpretations are limited by the resolution of the data and similarity to well-understood systems on Earth. In this work, we study a complex fluvio-lacustrine and eolian landscape at Deep Springs playa, California, using field measurements and remote sensing as an analog for a wet-to-dry-transitioning landscape on Mars. The playa system in arid Deep Springs reflects fluvio-lacustrine processes in its interior but transitions to eolian-dominated processes along the playa margin. Weather station data and field observations collected over 34 months illustrate the interplay between eolian and lacustrine processes and provide context for interpreting the observed geomorphology in aerial images. Our results showed a consistent distal-to-proximal geomorphic transition in the landscape defined by the changing expression of polygonal fractures, wave ripples, and evaporite deposits. Crescent-shaped sedimentary deposits, originally suspected to be related to barchan dunes, proved unrelated to eolian processes. We discuss the processes, sedimentary features, and climate drivers at Deep Springs to provide a potential framework for identifying and interpreting similar interactions between fluvio-lacustrine and eolian geomorphology elsewhere on Earth, on Mars, and beyond. [ABSTRACT FROM AUTHOR]

Much of the Martian surface is covered by a weathering layer (regolith or soil) produced by long-term surface processes such as impact gardening, eolian erosion, water weathering, and glacial modifications. China’s first Martian mission, Tianwen-1, employed the Mars Rover Penetrating Radar (RoPeR) to unveil the detailed structure of the regolith layer and assess its loss tangent. The RoPeR radargram revealed the local regolith layer to be highly heterogeneous and geologically complex and characterized by structures that resemble partial or complete crater walls and near-surface impact lenses at a very shallow depth. However, comparable radar data from the Lunar far side are rather uniform, despite the two surfaces being geologically contemporary. The close-to-surface crater presented in this study shows no detectable surface expression, which suggests an accelerated occultation rate for small craters on the surface of Mars as compared to the rate on the Moon. This is probably due to the relentless eolian processes on the Martian surface that led to the burial of the crater and thus shielded it from further erosion. The high loss tangent indicates that the regolith at the Tianwen-1 landing site is not dominated by water ice. [ABSTRACT FROM AUTHOR]

The coastal plain of Cabo Frio is located in an area where natural elements coexist (lagoons, restinga vegetation, stationary and transgressive dunes, etc.) with the urban site of the municipality. By investigating the dynamics and behavior of the megaform parabolic, an asymmetry was observed in its displacement over the plain, with different migration rates: 12.2m/year along its central axis, and 7.3m/year on the avalanche face. In terms of area coverage, it experienced a loss of 9.4 ha, resulting in a decrease of 13.6%. In addition to human presence, coastal environments can also be sensitive to environmental changes such as climate change and wave climates, which may lead to a landscape transformation process in this área. [ABSTRACT FROM AUTHOR]

The origin of volcanism in the Canary Islands has been a matter of controversy for decades. Discussions have hinged on whether the Canaries owe their origin to seafloor fractures associated with the Atlas Mountain range or to an underlying plume or hotspot of uprising hot material from the deep mantle. The debate has recently concluded, however, following the discovery of nannofossils preserved in the products of the 2011–2012 submarine eruption at El Hierro, which constrain the age and growth history of the westernmost island of the archipelago and so cement a clear East to West age progression within the archipelago. Light‐coloured, quartz‐bearing pumice‐like 'floating rocks' (xeno‐pumice) were found on the sea surface during the first days of the 2011 El Hierro eruption and proved to be fragments of pre‐island, sedimentary strata that were picked up by ascending magma. Upper Cretaceous to Pliocene calcareous nannofossils such as coccolithophores were retrieved from the xeno‐pumice fragments, and these marine micro‐organism biostratigraphical markers now provide crucial evidence that island growth at El Hierro commenced in the Pliocene. Here we discuss how these essentially continental (quartz‐bearing) sediments on the African continental shelf derive from dominantly wind‐blown Sahara dust and marine (re)‐deposition and describe present‐day aeolian processes that are in operation in the region. We investigate the mineralogy of Sahara dust that is currently deposited in the Canary Islands and discuss source areas and intra‐transport fractionation of mineral dust during trans‐Atlantic transport. Finally, we explore how present‐day dust deposition can be used as analogue to explain the deposition of pre‐island continental material in the East‐Atlantic Ocean basin beneath the Canary archipelago and we show how the dust‐derived sedimentary deposits can be utilized as geological tool in the Canary Islands. [ABSTRACT FROM AUTHOR]

Vesicular horizons are common on the surface of landforms in arid regions and play an important role in the hydrological properties and pedogenic processes in these areas. Vesicular pores are a characteristic feature of vesicular horizons and include separate pores with spherical to elliptical shapes and dimensions of micrometers to millimeters in diameter (Dietze et al., 2012). The eastern region of Isfahan located in the eastern part of the Zayandehroud River basin is affected by environmental disasters due to severe environmental drought, destructive human activities, and desertification processes. Although vesicular horizons are frequent in the soils and landforms of the eastern region of Isfahan (Bayat et al., 2018), there is no information about the geochemical and mineralogical properties of these horizons. The aim of the present study was to investigate the physical, chemical, geochemical, and mineralogical properties of vesicular horizons at different elevation levels of three landforms in the eastern region of Isfahan. Materials and Methods The study area is located in the center of Iran, east of Isfahan and around Segzi Playa. According to the meteorological stations of the region, the mean annual precipitation and temperature are about 107 mm and roughly 15 ˚C, respectively. Groundwater in piedmonts and plateaus of the region is deep and there are no signs of groundwater activity in the studied soils and landforms. The studied landforms include a remnant paleosurface across the Zayandehroud River (RP), a pediment in Jey industrial city (JP), and an alluvial fan near the Zefreh (ZA). Seven samples of vesicular horizons were taken from vesicular horizons in RP (at altitudes of 1542 and 1552 m), ZA (altitudes of 1623, 1764, and 1901 m), and JP (at altitudes of 1542 and 1557 m) landforms. The samples were described according to Schoenberger (2012) and analyzed regarding standard methods (Soukup et al., 2008; Soil Survey Staff, 2014). Results and Discussion The thickness of the studied vesicular horizons varied in the range of 3-6 cm, and on the alluvial fan, the thickness of the horizon increases with increasing the elevation. The chemical properties of the studied samples indicated very low electrical conductivity and organic carbon content and were similar to vesicular horizons in the Mojave Desert of California (McFadden et al., 1998). The particle size distribution indicated the predominance of sand particles in all samples and all samples were characterized by a bimodal distribution of particle sizes suggesting the contribution of at least two mechanisms in the transfer of particles to the studied vesicular horizons (Karimi et al., 2017; Sweeney et al., 2013). Mineralogical analysis of the samples showed the predominance of quartz and calcite in all samples and varied concerning the presence of mica and fibrous minerals. It seems that quartz is inherited from the parent material while calcite and mica minerals originated from the parent material and were also added by the wind. Fibrous minerals were probably of autogenic origin. The geochemical properties of the samples were consistent with the mineralogical results and showed the abundance of SiO2 and CaO in all samples. Among the trace elements, the highest abundance is observed in the strontium, which is due to the association of this element with carbonates (Ding et al., 2019). A comparison of geochemical properties of vesicular horizons with associated rocks showed the enrichment of SO3 and CaO relative to corresponding parent material indicating the addition of soluble ions, carbonates, and especially gypsum to the surface of the studied landforms. The Zr/Al ratio showed an increasing trend with increasing the silt content which proved the aeolian source of the silt particles as previous studies have shown a very strong correlation between aeolian sediments and the element zirconium (e.g., Waroszewski et al., 2018). Conclusions Increasing the amount of silt and the ratio of fine-grained particles to sand with increasing the elevation indicated the role of aeolian processes in adding fine-grained particles to the surfaces of different landforms of eastern Isfahan. Mineralogical and geochemical evidence also confirms the effect of dust on the formation of these horizons, so that the addition of mica minerals along with silt particles has occurred at higher altitudes. The geochemical study of vesicular horizons and application of Zr/Al ratios show that the composition of past and current dust in eastern Isfahan was the origin of dust for different landforms of the region is the same. Finally, the existence of developed vesicular horizons in the surfaces of the landforms of the region demonstrates long-term processes of wind erosion and dust influx into the soils. These natural processes are probably intensified by anthropogenic activities in recent years. [ABSTRACT FROM AUTHOR]

This paper is a summary of the results of research on the accumulation conditions of the Upper Younger Loess (LMg) in Poland and Bug loess (bg) in Ukraine from the maximum stage (MIS 2) of the Vistulian (Weichselian) Glaciation in central and eastern Europe. These studies included an analysis of the morphological (topographic) situation of the loess cover, its grain size and heavy mineral composition, the preserved structures of loess sedimentation as well as mollusc and pollen analyses of this loess. They revealed that the accumulation of Upper Younger Loess (UYL) might have been more dependent on the prevailing moisture conditions than previously thought. These conditions could have been caused by cold air masses from an ice sheet and warm air masses from the Mediterranean Sea and Atlantic coming together in the Carpathians and the Holy Cross Mountains and favouring the formation of dust storms and precipitation. In this process, a loading of loess dust (formed from local rocks weathering in periglacial conditions) by atmospheric moisture particles was especially significant. The moist substrate not only favoured the periodic development of vegetation and molluscs but also enabled the interception of dust and the accumulation of an increasingly thick loess cover. Westerly and south-westerly winds predominated in the UYL as indicated by the topographic position of loess patches and the mineral composition of the studied loess. Periodically an increased air circulation from the east and northeast occurred. [ABSTRACT FROM AUTHOR]

Eolian activity determines the magnitude of dust emission. However, geological records of eolian activity are scarce due to strong wind erosion in the dust source areas. Northern Xinjiang is recognized as a major dust source region in arid central Asia. Here we present a lacustrine record of eolian activity over the past 1600 years from Jili Lake, in northern Xinjiang, which acts a natural trap for airborne materials. Based on the stratigraphic variability of two sedimentary sequences and 20 radiocarbon dates, we infer that Jili Lake initially developed in the southwestern part of the lake basin during the mid-Holocene and then expanded to close to its modern surface area until 1600 years ago. Grain-size analyses of materials from different parts of the lake sedimentary system, including lake surface sediments, lake catchment deposits, and airborne sand and dust collected from near the lakeshore, demonstrate that the coarse silt and fine sand fraction (40–200 μm) of the lake sediments was transported primarily by strong winds and can be regarded as an indicator of changes in eolian activity. We argue that wind strength played an important role in lifting and transporting the coarse particles, although an arid climate cannot be entirely excluded out as a factor favoring eolian activity. The most intensive eolian activity occurred from ∼910 to 1300 AD, roughly corresponding to the Medieval Warm Period (MWP), whereas eolian activity was weak during the Little Ice Age (LIA, ∼1300 to 1760 AD). However, this pattern is inconsistent with other dust records from central Asia. Eolian dust activity reflects the coupling of dust-generating windstorms and dust source areas which were swept by cold air surges. The spatial differentiation of eolian dust activity in arid central Asia may thus be causally linked to the intensity and extent of the Siberian High (SH), given that intense cyclogenesis always occurs on the southwestern periphery of the SH in springtime. Changes in the SH can be further ascribed to atmospheric circulation modulated by phase alternations of the North Atlantic Oscillation (NAO) due to large-scale thermal contrasts. Our results suggest that the dynamics of Asian dust emission are closely linked with the spatial variability of the SH. Nonetheless, more records of eolian activity are needed to further elucidate the forcing mechanisms of dust entrainment in the source area of Asian dust. [ABSTRACT FROM AUTHOR]

Concentrated Solar Power (CSP) plants are typically located in gravelly desert (Gobi) regions because of their level, steady land, and abundant sunlight. The Gobi region has many sand sources, and strong winds accelerate aeolian processes, leading to windblown sand and dust at CSP sites. Large-scale CSP plant heliostats and central building clusters affect Gobi surface aerodynamic roughness and flow field characteristics, leading to a distinct aeolian transportation mechanism compared with that of a natural Gobi surface. Field observations from the 100 MW large-scale Gobi central-tower CSP facility in Dunhuang, China, were used to study a typical aeolian transportation event to gain insight into windblown sand and dust movement in CSP plants. The plant experienced a 36 % reduction in wind friction velocity owing to the increased aerodynamic roughness compared to that in the external environment. The facility reduces the minimum wind friction velocity for sand particle initiation to 0.37 m s−1, which is 30 % lower than that over the typical Gobi surfaces, however, sand accumulation between the heliostats resulted in a 1.8 times higher sediment transport quantity than that transported externally. The blown sand mean saltation layer height in the plant was 0.09 m, similar to that of a sandy desert. The plant surface emits dust, causing PM10 levels to increase to 20,000 μg m−3. Large-scale CSP facilities should remove sand build-up and use windblown sand management methods, such as checkerboard sand barriers and sand-blocking fences, to minimize aeolian transport and dust concerns. • The friction wind velocity inside the Gobi CSP plant experiences a 36 % reduction. • The average saltation layer height inside the plant is 0.09 m, like that of a sandy desert. • Sediment transport quantity inside the plant is 1.8 times higher than that outside the plant. • The plant's surface emits dust, causing PM10 levels to rise to 20,000 μg m−3. • Windblown sand management methods are recommended to minimize aeolian transport. [ABSTRACT FROM AUTHOR]

It is unresolved when eolian processes began to significantly affect global mean sand composition and texture through abrasion and enhanced sorting. Reports of Proterozoic eolian textures and sedimentary structures are common, in particular from 1.8 Ga on, but the Archean (4.0–2.5 Ga) geologic record possesses only seven reported eolian occurrences which generally do not manifest more than a few diagnostic features of eolian transport. We investigate in detail sandstone units within the Moodies Group (ca. 3.22 Ga) of the Barberton Greenstone Belt, South Africa, one of the oldest well-preserved terrestrial–marine sandy successions. Eight examined locations show terrestrial facies associations, high degrees of compositional and textural maturity, and large-scale foresets; however, none show convincing evidence of eolian transport but several can be excluded with confidence. In comparison to recent eolian strata, grains are generally slightly too coarse-grained, too angular, and mostly too poorly sorted. The common presence of shale laminations, granules, rare pebbles, and shale rip-up clasts demonstrates that the investigated strata were either of aqueous origin or had been formed by eolian processes but were subsequently aqueously reworked. This is vexing because the sandy-gravelly fluvial, coastal floodplain, and estuarine depositional environments of Moodies Group strata may have been hospitable to potentially powerful and long-lasting Archean eolian processes. Early Archean eolian strata may have had a limited depositional area, may have been extensively reworked, or formed under non-actualistic conditions. Thus, the significance of eolian processes on early Earth and their potential contribution to the high degree of textural and compositional maturity of Archean quartzarenites remains poorly constrained. [ABSTRACT FROM AUTHOR]

• For the first time, we determined the geographical boundaries where desert provenance differs • Quantitative provenance analysis was conducted on aeolian sands with various grain size fractions. • We determined the spatial pattern of sediment contribution from different sources. • Both internal and external sediments contribute to the sand accumulation in desert. • The coupling of fluvial and aeolian processes represents sediment transport in desert. Understanding and quantifying aeolian sediment sources in sand seas is imperative to elucidate their formation mechanism and promote ecological restoration, particularly in transitional zones between agricultural farming and animal grazing. Despite considerable efforts to identify the provenance of the Mu Us Sandy Land (Mu Us), a clear boundary demarcating the provenance differences between its western and eastern regions remains elusive. Furthermore, the quantitative contributions of its potential source areas are yet to be determined. This study elucidated these aspects using robust source indicators and the MixSIAR fingerprinting model, underpinned by geochemical data. Utilizing provenance indicators such as the K/Ba, K/Rb, Ba/Sr, and Rb/Sr ratios, this study identified the line connecting Angsu and Huanghaojie Town as the clear boundary demarcating the provenance differences between the western and eastern Mu Us. The eastern Mu Us's coarse sand primarily derives from underlying sandstones (70.5%) and local fluvio-lacustrine deposits (29.5%), while the western region's coarse sand predominantly originates from Yellow River (YR) sediments in the Yinchuan Basin, transported from the Northeastern Tibetan Plateau (NTP) (82.2%), and local fluvio-lacustrine deposits (17.8%). Similarly, the Mu Us's fine sand mainly originates from local fluvio-lacustrine deposits, contributing 66.5% and 67.6% to the fine sand in the eastern and western regions, respectively. Under strong westerly winds, Gobi deposits from upwind areas contribute 33.5% and 32.4% of fine sediments to the eastern and western Mu Us, respectively. The spatial heterogeneity of material sources in the Mu Us highlights the combined influence of fluvial and wind processes. Lacustrine deposits play a crucial role in the sediment provenance of the Mu Us. This study demonstrates that the MixSIAR model constitutes an effective approach for quantitative provenance research in deserts located in climatic transitional zones worldwide. [ABSTRACT FROM AUTHOR]

While the impact of the spatio/temporal variability of grain size on morphological beach state is reasonably well understood, relatively little is known on its impact at a scale of days/months on aeolian sediment transport. This study focuses on five short intensive wind events during which aeolian sediment transport measurements, beach surface sampling and elevation change surveys were carried out for 1 to 3 days, over a 16-month period on a microtidal beach dominated by offshore winds. Monthly observations show a high temporal variability in beach grain size in relation to the decoupling between hydrodynamic and aeolian processes, from medium sand after a marine storm and inundation of the beach, to very coarse sand after several weeks of storm-force winds. During each wind event, topographic change on the beach ranged from zero, to 0.55 m. The time scale of coarsening depended on the initial beach grain size and could be very fast when the beach was composed of medium sand (e.g. 388 μm sand changed to coarse sand of 547 μm in 40 h). In contrast, it took one month to transition from a coarse median beach grain size of 883 μm to a very coarse one of 1323 μm. This variability in grain size results in dramatically different rates of sediment flux. For example, during average wind speeds of 10 to 14 m/s the sediment flux when the beach was composed of medium sized sand ranged between 21 and 154 kg/m/h compared to 0.4 to 50 kg/m/h when the beach was composed of coarse and very coarse sized grains. Overall, this study highlights the importance of beach grain size variability on aeolian sediment transport and shows that for similar incident wind and climatic conditions aeolian sediment transport rates vary dramatically. The study demonstrates the importance of taking care when using a constant median grain size in the calculation of long-term aeolian sand transport on beaches with heterogeneous spatial and temporal beach grain size variability. • Transport rates can be ten times greater on medium-sized beach than coarse one. • Offshore wind generate a grain size sorting, the finest sands are exported seaward. • Topographic variations of the beach depends on its grain size and sand supply. • The return of fine sediments depends on marine storms occurrence and intensities. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the environmental factors that influence the orientation of lakes and basins in continuous permafrost of the Yana–Indigirka Lowland, NE Siberia. In this area, 24,782 lakes each with an area of >10,000 m2 were digitized from Google Earth satellite imagery, and four categories of lakes and drained lake basins were identified in two sub-study areas from Sentinel 2 imagery. Regionally, the lakes show a single modal orientation east–west to ESE–WNW, which is broadly parallel to the prevailing wind from 80 to 90° recorded at the nearest meteorological stations during June–October, when the lakes are likely to have been partially or completely ice-free and therefore exposed to wave-induced currents. Regression analysis suggests that lake orientation tends to be strongest in flatter terrain (<1°) that is not formed in silt- and ice-rich yedoma deposits. Locally, however, two sub-study areas show two modes of almost equal size, with lakes and basins aligned ESE–WNW or NNE–SSW, and thus approximately either parallel to or perpendicular to prevailing winds. Local deviation from the ESE–WNW lake alignment in the sub-study areas is attributed to a sandy substrate and topographic control. Sandy substrates appear to favour perpendicular orientations, whereas elongate depressions aligned broadly east–west, and supporting meandering rivers, favour parallel orientations. Overall, therefore, the impact of prevailing summer wind direction on lake and basin orientation is moderated by environmental factors of topography and substrate. • Regionally, lakes tend to be oriented east–west, parallel to prevailing wind. • Such orientation is strongest in flattish terrain not underlain by silty yedoma deposits. • Locally, lakes and basins are aligned parallel or perpendicular to prevailing wind. • Local, perpendicular orientation is favoured by sandy substrates. • Local, parallel orientation occurs along linear, topographic depressions. [ABSTRACT FROM AUTHOR]

The rock size-frequency distribution (RSFD) is important in studying the geological evolution history of planetary surfaces and in the selection of landing sites for planetary rovers. Different from previous studies that analyzed rock distribution for only several waypoints, we identified and measured rocks along the entire traverse of the Zhurong rover. An interactive rock measurement system was developed for stereo images captured by navigation and terrain camera (NaTeCam) and a total of 5983 rocks >10 cm in diameter was identified and measured within 10 m at discrete waypoints. The result shows the abundance of rocks <120 cm along the traverse is approximately 3–4% with an average of 3.3%, consistent with multi-source rock abundance products. Rock abundance at each waypoint mostly ranged from 2% to 5%. The widespread presence of duricrusts resulted in the deviation of the RSFD curve from the model owing to their morphological characteristics. A comparison of the cumulative fractional area curve with Spirit and Insight landing areas indicated a similarity to the rock distribution patterns. It can be inferred that small impacts since the Amazonian have been the primary source of the rocks, with subsequent resurfacing process, e.g. aeolian process, fragmented these rocks. The results of this study provided valuable insights on the distribution pattern, formation and evolution of the rocks in the Zhurong rover's landing area. • 5983 rocks>10 cm are measured by an interactive self-develop tool based on NaTeCam images. • The abundance of rocks<120 cm is 3–4%, with an average of 3.3%. • The large diameters (> 60 cm) of the duricrusts make the RSFD higher than the expected value of the model. [ABSTRACT FROM AUTHOR]

We studied a multisequal soil succession (MSS) just south of Torres del Paine National Park (51°S), at the present-day core of the Southern Westerly Winds (SWW). The Río Serrano Section comprises paleosol horizons with associated intervening loess and sandy loess beds formed during the Holocene. Our record suggests strong and stable aeolian activity between ∼9.3–7.2 ka followed by a decline with centennial-scale variations until ∼5 ka. A strengthening commenced at ∼5 ka and culminated in a maximum between ∼2.2–0.5 ka with millennial-scale variations. Subsequent weakening of aeolian activity between ∼0.5 and 0 ka was coeval with the deposition of a ∼40 cm-thick paleosol, after which aeolian activity increased abruptly and reached an unprecedented maximum starting in the mid-20th century. The inferred wind intensity variations from our data bear partial agreement with competing hypotheses of SWW evolution, which postulate minimum SWW influence in SW Patagonia during the early Holocene and maximum influence during the Late Holocene, or vice versa. When analyzed through the lens of vegetation physiognomy/distribution and associated hydrological balance inferences from neighboring sites, our results suggest a primary control by precipitation and wind speeds associated to SWW strength at regional scale, modulated by the position of the forest/steppe ecotone east of the austral Andes. Human activities during the mid-20th century (deforestation, fire-regime shifts, livestock grazing, land use changes) caused an unprecedented increase in aeolian activity through decreased vegetation cover that increased sediment availability for aeolian transport, marking a striking difference with the magnitude of natural processes before the Anthropocene. Our results highlight the importance of climate change and natural/human-driven changes in vegetation cover for deciphering wind intensity histories, particularly in the transition from humid to semiarid environments along the eastern slope of the southern Patagonian Andes. • The Southern Westerly Winds (SWW) play a key role on global climate. • SWW Holocene changes in Southern South America (SSA) are still matter of debate. • Most of SWW reconstructions in SSA are based on indirect proxies of wind intensity. • Vegetation cover is a key factor on wind transport affecting sediment availability. • This is particularly significant in the transition from humid to arid environments. [ABSTRACT FROM AUTHOR]

The northeastern part of the Ebro Basin (NE Spain) features loess that cover an area of about 40 km2 on the northern slopes of the Serra d'Almenara anticline. The deposits and soils developed from them were mapped, described, and dated by luminescence. Additionally, grain size, percentage of heavy minerals (>2.8 g/cm3), and the mineralogical composition of the heaviest fraction (>3.2 g/cm3) were analysed. The coarse textures of the deposits indicate a very proximal origin. Therefore, potential source areas of the sands and silts were analysed with special attention given to the extensive river floodplains and alluvial fans close by, as well as gypsum-rich rocky outcrops. The mineral signature of the loess shows that it mainly originates from the alluvial plain of the Segre River, located about 10–30 km to the west. In some places, the loess also received particles from the alluvial fans of the Ondara and Corb rivers located south of the Almenara reliefs. In addition, the gypsum present in the loess is apparently derived from Eocene deposits. The loess in the study area was deposited during cold phases of the last two glacial cycles when the topographic obstacle of the Serra d'Almenara blocked the dominant winds from the southwest. Analysis of the almost 4-meter-thick profile of Pilar d'Almenara shows initial but limited accumulation phases in Marine Isotope Stages (MIS) 6, followed by the formation of a red soil during MIS 5e. Accumulation resumed during MIS3, with more energetic and powerful wind transport during the final phase of MIS 3 (ca. 34–30 ka) and early MIS 2, but prior to the Last Glacial Maximum. Our data highlights the prominent role of large rivers and alluvial fans as the sources of particles that are later reworked by the wind. • The most important heavy mineral species as tracers are zircon, staurolite, rutile and inosilicates. • Diiodomethane facilitates the recognition of very heavy minerals in sands. • Luminescence dating, together with the particle size and mineralogical results, allow for the identification of periods of maximum activity and the origin of materials in each era. [ABSTRACT FROM AUTHOR]

• A three-stage alluvial fan pattern was built since MIS3. • Cold-dry conditions promote the aggradation of debris flow deposits. • Warm-humid climate leads to perennial streamflow on the fan surface. • Climate is the main factor controlling the evolution of Xiangpi fan. Alluvial fans in the piedmont zones of mountains respond most rapidly to tectonic activity, base-level conditions, and climate changes. These allogenic signals are effectively recorded by the external morphology and internal sedimentary characteristics of the fan. Based on field survey interpretation and integrated optically stimulated luminescence (OSL) chronology, we selected a case study of the modern Xiangpi Fan on the south bank of Lake Qinghai, NE Tibetan Plateau, and built a three-stage alluvial fan pattern since Marine isotope stages 3 (MIS3), namely, the debris flow lobe building stage (DFLBS), aeolian building stage (ABS), and streamflow reworking stage (SRS). The climatic indicators, such as the total organic carbon (TOC) flux, precipitation, and sediment particle size flux, are highly correlated with the above stages, indicating that the sedimentary process and changes in fan morphology effectively record orbital climate changes in the Lake Qinghai basin. During the DFLBS, the cold-dry climate accelerated the sediment yield sufficiently, leading to many coarse-grained sediments and low TOC flux being imported into the basin through debris flow processes. During the ABS, the extreme dry-cold climate caused the stagnation of fan development, and aeolian processes dominated the transport of fine sediment. In the SRS, warm-humid conditions led to limited sediment yield and perennial stream power, which promoted the transport of fine-grained material and TOC to the basin by braided–meandering channels. This study provides an excellent case showing how an alluvial fan responds to climate oscillations through changes in sedimentology and geomorphology. [ABSTRACT FROM AUTHOR]

Previous studies of wind‐blown sand have considered either fully erodible or non‐erodible soils, but the transport over sparsely sand‐covered soils is still poorly understood. The quantitative modeling of this transport is important for parameterizing Aeolian processes under low sand availability. Here we show, by means of numerical simulations, that the sand transport rate Q scales with the wind shear velocity u∗ as Q=a⋅1+b⋅u∗/u∗t−1⋅d/g⋅ρf⋅u∗2−u∗t2 $Q=a\cdot \left[1+b\cdot \left({u}_{\ast }/{u}_{\ast \mathrm{t}}-1\right)\right]\cdot \sqrt{d/g}\cdot {\rho }_{\mathrm{f}}\cdot \left({u}_{\ast }^{2}-{u}_{\ast \mathrm{t}}^{2}\right)$, where u∗t is the minimal threshold u∗ for sustained transport, d is particle size, g is gravity and ρf is air density, while u∗t and the empirical parameters a and b depend on the sand cover thickness. Our model explains the transition from the quadratic to cubic scaling of Q with u∗ as soil conditions change from fully erodible to rigid and provides constraints for modeling Aeolian transport under low sand availability. Plain Language Summary: The transport of sand by wind shapes the Earth's surface and constitutes one major factor for the emission of dust aerosols. The accurate modeling of wind‐blown sand transport is thus important to achieve reliable climate simulations and to make predictions about the propagation of desertification. Previous models of wind‐blown sand were designed to compute sand transport rates over a thick sand layer, such as the surface of large, active sand dunes. However, natural soils encompass a broad range of low sand availability conditions, such as crusted or bare soils. It has been a long‐standing open question how wind‐blown sand transport rates respond to wind velocity when the bare ground is covered by a thin layer of sand. Here we calculate the trajectories of wind‐blown sand grains and find that sand transport rates increase faster with wind speed under low sand availability conditions than over sand dunes. The reason for this behavior is elucidated in our simulations: The hopping sand grains fly higher the less sand is covering the hard surface. We obtain mathematical expressions for the sand transport rates as a function of the thickness of sand covering the bare soil, which will be important to improve climate models. Key Points: We introduce a particle‐based model in investigating Aeolian (wind‐blown) sand transport when the sand cover on the soil is sparseThe scaling of the Aeolian transport rate with the wind shear velocity has a dependency on the sand cover thicknessThere is an anomaly in the functional dependence of the transport rate on the sand cover thickness, depending on the rigid ground roughness [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Site formation processes at ancient tells in the southern Levant have been the focus of several micromorphological studies, contributing to the differentiation of anthropogenic remains from long-term natural sedimentation, occurring post-abandonment. This paper discusses how the study of sedimentary processes and chemical compositions of sediments can be used within the context of an ongoing archaeological project, and how they can contribute to archaeological, historical and geomorphological interpretations. Sedimentary processes were studied implementing POSL, granulometry and PXRF as part of the archaeological research at Tel Burna, Israel. Focusing on the area along the northwestern fortification walls (Area B2), data was collected from multiple strata inside and outside the casemate fortifications dating from the Late Bronze Age to the Late Iron Age. The gradual increase of OSL values obtained inside the casemate wall, indicate accumulation of sediment during a long period of time. Whereas similar values along the entire profile outside the casemate wall indicate sediment accumulation in one-time event. This might be related to defensive preparations, allegedly in response to advances made by Sennacherib's army in 701 BCE. In addition, results from the PXRF studies demonstrated correlation between human activities and the Cu, P, K, Zn, Mn values. Specifically, it was found that as K content increased from younger to older periods, it can be used as a pseudo-dating element. Ca content decreased as sampling descended from the tell's surface, suggesting its origin in long-term aeolian processes. The results show that the use of POSL and PXRF on archaeological contexts are useful for determining sedimentary processes. Furthermore, chemical content enabled pseudo-dating of strata and facilitated the distinction between natural and anthropogenic processes in archaeological sites and landscape. • Elemental stratigraphic gradients correlate with chronology (Ca, P, K, Mn, Zn). • Human activities revealed by Cu, P, K, Zn, and Mn. • Geochemistry could be used as a pseudo-dating method (K content). • Higher content of Ca in younger phases/topsoil is probably due to aeolian deposition. [ABSTRACT FROM AUTHOR]

Titan, the largest moon of Saturn, is characterized by gigantic linear dunes and an active dust cycle. Much like on Earth, these aeolian processes are caused by the wind‐driven saltation of surface grains. It is still unclear, however, how saltation on Titan can occur despite the typically weak surface winds and the potentially cohesive surface grains. Here, we explore the hypothesis that saltation on Titan may be sustained at lower wind speeds than previously thought, primarily through granular splash rather than aerodynamic lifting of surface grains. We propose a saltation mass flux parameterization for Titan and use it to quantify sediment transport with a general circulation model. The results suggest that Titan's prevailing circulation can generate highly intermittent yet significant saltation, with mass fluxes of the order of 104 kg m−1 year−1, and that Titan dunes may be formed primarily by fine grains, approximately 0.1 mm in size. Plain Language Summary: The Cassini‐Huygens mission has revealed that Titan's landscape evolution and dust cycle may be controlled by the wind‐driven transport of surface grains, known as saltation. It is still unclear, however, how saltation can occur on Titan despite the weak winds and the potential stickiness of the surface grains. Using a combination of experiments, theory, and modeling, we find that, like saltation on Mars, saltation on Titan can be sustained at much lower wind speeds than those required to lift grains from the surface. Accordingly, the prevailing weak winds on Titan may be capable of driving intermittent yet significant sediment transport. Key Points: Intermittent saltation on Titan can be sustained at lower wind speeds than previously thoughtThe grains forming Titan dunes may be primarily in the size range 0.05–0.1 mmYearly sediment transport rates on Titan are of the order of 104 kg m‐1 per Titan year [ABSTRACT FROM AUTHOR]

Cliff‐related talus accumulations are often highly affected by post‐depositional processes, and the sedimentological characteristics are poorly documented, especially in arid settings. In the southern margin of the Fergana Valley, Kyrgyzstan, the Obishir‐I is an archaeological site of the Epipaleolithic Obishirian industry, located within a talus cone. Archaeological excavations have allowed us to study the internal structure, chronology, and depositional history of the cone as well as the relationship between the slope processes and the archaeological assemblage. We applied a multiproxy approach, including sedimentological studies supported by the basic geochemistry of sediments, luminescence dating, paleoecology of fossil mollusks, and archaeological analyses. The Obishir‐I rockfall talus accumulated from the Last Glacial Maximum to the early part of the Middle Holocene. The talus onlaps the bedrock at the foot of a limestone cliff, and its chronology is coherent, spanning from ca. 19–8 ka B.P. The material is an unconsolidated, poorly sorted mixture of angular rock fragments accumulated by rockfall and fine‐grained materials accumulated by aeolian processes, illuviation, and in situ weathering. The sequence bears an archaeological collection attributed to two settlement phases: unidentified Upper Paleolithic and the Obishirian. Both assemblages are affected by post‐depositional relocation within the slope. [ABSTRACT FROM AUTHOR]

Icelandic soils develop in a dynamic environment affected by both natural processes and anthropogenic impacts. We present an extensive investigation of soil mineralogy and pedogenesis in a disturbed (i.e., by solifluction) pedon under such conditions. The study focuses on two distinct tephra layers, a rhyolitic tephra from the Öræfajökull eruption in 1362 CE (Ö1362) and a basaltic Veiðivötn tephra from 1477 CE (V1477). Both tephra layers form an important parent material in the study area south of Vatnajökull, Iceland. The Andosol developed from tephra and aeolian material, rich in volcanic glass. The pH (H2O) values were between 5.5 and 6.6 and clay mineralogy displayed a predominance of allophanic material in both soil and tephra. The pedon can be seen in its early stage of chemical weathering and soil development. Despite the overall predominance of non‐ and poorly‐crystalline short‐range order secondary materials and Fe (hydr)oxides in the clay‐size fraction, we found indication of smectite. High exchangeable Ca2+ and Mg2+ concentrations reflect enhanced aeolian input of volcanic material, while elevated exchangeable‐Na+ concentrations are most likely caused by the oceanic composition of precipitation. The impact of erosion and aeolian processes on pedogenesis seemed to be higher between the deposition of Ö1362 and V1477, than in the soils above. Both, soil and tephra layers appeared disturbed by erosion–deposition processes over time. Characterised by a significantly coarser particle size composition, low soil organic carbon (SOC) content, and a more diverse mineralogy, a distinct fluvial sediment layer at 10–30 cm depth appeared sharply contrasting to the other soil layers in the profile. This possibly reflects the diverse composition of glaciofluvial material from a landslide originating from a Kvíárjökull moraine in the north. Changed weathering patterns and properties in the soils above the Ö1362 tephra indicated soil degradation following the deposition of the rhyolitic tephra. [ABSTRACT FROM AUTHOR]

We analyze major landforms of the Lut Desert in Iran to provide a comprehensive source‐to‐sink picture of aeolian systems on time scales from decades to millions of years. We map the modern sandflows, along which we evaluate the volume and chronology associated with the excavation of mega‐yardangs upwind and the formation of giant dunes downwind. Sediment discharges deduced from long‐term erosion and deposition are of the same order of magnitude (105–106 m3 yr−1) as short‐term and medium‐term sand discharges derived from wind data and dune morphodynamics. At the scale of the internal aeolian sediment‐routing system of the Lut, we establish an overall sediment budget constrained by the joint development of the erosional and depositional landforms. Our findings thus quantify the geomorphic controls of aeolian processes on arid landscapes at multiple length and time scales, while providing information on mass exchanges between continents and atmosphere. Plain Language Summary: Wind‐blown sand and dust emissions shape singular landscapes in arid environments and globally impact climate, life, and human activities. Nevertheless, the contributions of aeolian processes to the evolution of continental surfaces and to their mass exchanges with oceans and the atmosphere are still subject to considerable uncertainties. Compared to sediment transport in rivers, this is because wind transport is not associated with a well‐identified channel network that directly links sand and dust production (source) to accumulation (sink) areas. The Lut Desert in Iran is nested in a closed topographic depression which provides an appropriate context to investigate the work of the wind. Spectacular landforms called mega‐yardangs and giant dunes are used together with modern wind data to map and quantify sandflows at different time scales. These sandflows are consistent with each other from decades to millions of years and allow to estimate the amount of sediments transported across the Lut Desert or emitted into the atmosphere. These estimates are not only important for the management of terrestrial drylands, but they can also provide information about the past evolution of planetary bodies dominated by aeolian processes such as Mars or Titan. Key Points: The wind regimes within the Lut Desert create an internal aeolian sediment‐routing systemThe joint development of erosional and depositional landforms are consistent with modern sandflowsSource‐to‐sink aeolian fluxes are of the same order of magnitude from decades to millions of years [ABSTRACT FROM AUTHOR]

Drylands are arid and semi-arid areas whose main feature is their low level of precipitation. They cover nearly half of Earth's land surface and are distributed worldwide, constituting the planet's largest biome. Dryland soils have low fertility, are greatly affected by climate variability, and are vulnerable to wind and water erosion. The phosphorus-rich soil dust traveling by aeolian processes from drylands is the main source of P for the global primary productivity in P-limited areas, a fact that highlights the importance of arid and semiarid areas in the global nutrient budget. This review discusses the development of dryland soils, the sources of P in drylands, the C, N, P, relation in dryland soils, the fractionation and bioavailability of P, and biotic and abiotic factors affecting the P in drylands. Finally, the dynamic of P in biological soil crusts and resource islands is discussed. Combined, they contribute to the surface organic matter pools, alter the soil fertility, and are determinant factors in P's availability in dryland soils. We conclude the review by highlighting the gaps in knowledge that should be addressed in future research regarding biological and abiotic processes that determine the dynamics of P in drylands. [ABSTRACT FROM AUTHOR]

Diatom metacommunities are structured by environmental, historical, and spatial factors that are often attributed to organism dispersal. In the McMurdo Sound region (MSR) of Antarctica, wind connects aquatic habitats through delivery of inorganic and organic matter. We evaluated the dispersal of diatoms in aeolian material and its relation to the regional diatom metacommunity using light microscopy and 18S rRNA high‐throughput sequencing. The concentration of diatoms ranged from 0 to 8.76 * 106 valves · g−1 dry aeolian material. Up to 15% of whole cells contained visible protoplasm, indicating that up to 3.43 * 104 potentially viable individuals could be dispersed in a year to a single 2 ‐cm2 site. Diatom DNA and RNA was detected at each site, reinforcing the likelihood that we observed dispersal of viable diatoms. Of the 50 known morphospecies in the MSR, 72% were identified from aeolian material using microscopy. Aeolian community composition varied primarily by site. Meanwhile, each aeolian community was comprised of morphospecies found in aquatic communities from the same lake basin. These results suggest that aeolian diatom dispersal in the MSR is spatially structured, is predominantly local, and connects local aquatic habitats via a shared species pool. Nonetheless, aeolian community structure was distinct from that of aquatic communities, indicating that intrahabitat dispersal and environmental filtering also underlie diatom metacommunity dynamics. The present study confirms that a large number of diatoms are passively dispersed by wind across a landscape characterized by aeolian processes, integrating the regional flora and contributing to metacommunity structure and landscape connectivity. [ABSTRACT FROM AUTHOR]