Aeolian Sand Research Articles

Dynamic Coupling Between Intensified Physical Erosion and Asian Dust Activity Under Late Cenozoic Global Cooling

AbstractDistinguishing the independent contributions of tectonic denudation and climate‐driven erosion on the production and supply of clastic materials of Chinese eolian deposits is important in understanding the dynamic links between global climate changes, tectonics, and Asian dust emission. Here, multi‐proxy rock magnetic records of detrital fractions of Chinese eolian deposits since ∼6 Ma, combined with further comparison with dust accumulation rates and geochemical data, suggest that limited production and supply of clastic materials of Chinese eolian deposits were observed between 5.6 and 4.4 Ma in a warmer climate, and thereafter an increasing trend is evident during a cooler world. We propose that intense physical erosion under cooler conditions caused increasing production of fresh detrital components, exerting dominant influences on the sediment supply to Asian eolian deposits. This study provides direct evidence of dynamic coupling between intensified physical erosion and Asian dust activity under late Cenozoic global cooling.

Sensibility in the impact of aeolian sand cover on permafrost degradation in Qinghai-Xizang Plateau

Abstract Environmental transformations and intensifying desertification across the Qinghai-Xizang Plateau significantly influence permafrost degradation, heightening risks associated with carbon emissions, thermal hazards, and infrastructural damage. However, the specific response of permafrost to desertification remains insufficiently understood. Here, we employed numerical modelling to examine the sensitivity of the impact of aeolian sand cover (ASC) on permafrost degradation. Our findings reveal that the thickness and moisture content of ASC profoundly affects permafrost degradation. Moreover, permafrost thermal stability and the rate of climatic warming modulate this degradation process. The simulation results identify two critical thickness thresholds for ASC: 20 cm and 80-120 cm. Specifically, dry ASC thinner than 20 cm accelerates permafrost degradation driven by desertification, whereas ASC thicker than 20 cm mitigates this effect. Furthermore, increased moisture in ASC extends the thickness thresholds to 80-120 cm. These results suggest that climatic variations in the Qinghai-Xizang Plateau, particularly transitions towards either warming-drying or warming-wetting, will markedly influence the response of permafrost to desertification. Notably, a warming-drying climate may reduce the potential degradation of permafrost caused by desertification. This study provides a critical reference for understanding the impact of aeolian desertification on permafrost in regions beyond the Qinghai-Xizang Plateau. It holds significant policy implications for environmental conservation and infrastructure development within the plateau.

Insights into Martian bedform migration: Results from Gale, Jezero and Pasteur craters

AbstractAn attempt is made in this study to advance the understanding of the sand movement on Mars by studying the bedform migration at Gale, Jezero and Pasteur craters. The study on the grain size distribution at Gale Crater using Curiosity rover (MAHLI and APXS) observations reveals that the grains with smaller diameters (~50–150 μ) are more prone to migration and vice‐versa, which gives an idea of the necessary requirements that initiate bedform migration. The chemical analysis of the surface materials at the Gale crater revealed elevated concentrations of P2O5, SO3, Cl and Zn in soil compared to sand and active transportation processes for sand but not soil. The comprehensive chemical makeup of the Martian soil (inactive bedforms) and sand (active bedforms) is characterized by its basaltic nature, with enriched volatile elements such as sulphur, chlorine and zinc, and the presence of minerals like plagioclase, pyroxene and olivine due to the cohesive nature of inactive bedforms. Physical weathering and wind flow velocity play a pivotal role in the formation of different sedimentary bodies, impacting grain size distribution and mineralogy. The effect of dust‐lifting on surface features is studied by analysing Perseverance‐MEDA observations at the Jezero crater to understand the short‐term changes in the bedform. These events are found to involve the redistribution of only a small amount of materials and, thereby, changing surface features on Mars over a short period. To detect the bedform migration in the Pasteur crater, several HiRISE images acquired over different time intervals were used. The changes in the ripple crest (~0.29–1.18 m/Earth year) and dune slip face suggest new grain flow events. In the Pasteur crater, extensive changes in sand deposits near the dunes signify a widespread bedform migration. The stronger north‐westerly and north‐easterly winds dominate these changes. Thus, the bedform migration in the three tropical craters exhibits significant variability driven by localized aeolian processes. This variability is crucial for understanding Mars' geological history, current surface dynamics and eventually, helps in planning future missions.

Monitoring Aeolian Erosion from Surface Coal Mines in the Mongolian Gobi Using InSAR Time Series Analysis

Surface mining in the southeastern Gobi Desert has significant environmental impacts, primarily due to the creation of large coal piles that are highly susceptible to aeolian processes. Using spaceborne remote sensing and numerical simulations, we investigated erosional processes and their environmental impacts. Our primary tool was Interferometric Synthetic Aperture Radar (InSAR) data from Sentinel-1 imagery collected between 2017 and 2022. We analyzed these data using phase angle information from the Small Baseline InSAR time series framework. The time series analyses revealed intensive aeolian erosion in the coal piles, represented as thin deformation patterns along the potential pathways of aerodynamic transportation. Further analysis of multispectral data, combined with correlations between wind patterns and trajectory simulations, highlighted the detrimental impact of coal dust on the surrounding environment and the mechanism of aeolian erosion. The lack of mitigation measures, such as water spray, appeared to exacerbate erosion and dust generation. This study demonstrates the feasibility of using publicly available remote sensing data to monitor coal mining activities and their environmental hazards. Our findings contribute to a better understanding of coal dust generation processes in surface mining operations as well as the aeolian erosion mechanism in desert environments.

Quantitative contributions of different atmospheric circulation systems to Holocene aeolian activity in northwestern China: Evidence from a closed interdune lake in the Tengger Desert hinterland

The aeolian deserts of northwestern China are major landscape types in the arid regions of the Northern Hemisphere, and collectively they are one of the largest dust source regions on Earth. However, owing to occurrence of sedimentary hiatuses within aeolian deposits in the deserts, we lack clear knowledge of the history of Holocene aeolian activity and the interaction between aeolian processes and their potential drivers. In this study, we extracted an environmentally sensitive grain-size component from the sediments of a closed interdune lake in the hinterland of the Tengger Desert. Our methodology included the application of End Member Analysis (EMA) of different modern sediment types from catchment to regional scales. We reconstructed aeolian activity over the past 13 cal ka BP and quantified the contributions of environmental factors. The results indicated that the EM 2 fraction of the interdune lake sediments is mainly transported by local winds and reflects changes in the intensity of aeolian activity. Based on EM 2 the strongest aeolian activity occurred during 13.0–7.0 cal ka BP, especially during 8.0–7.0 cal ka BP, and the weakest activity occurred during 7.0–3.5 cal ka BP. Aeolian activity increased after 3.5 cal ka BP, but with a gradually weakening trend. The occurrence of the weakest aeolian activity in the Tengger Desert during the Middle Holocene differs from that on the Asian Summer Monsoonal Boundary and in the area influenced by the Westerlies-dominated climate regime. Thus, there was a clearly defined spatio-temporal differentiation of Holocene aeolian activity across the deserts and dune fields of northern China. Quantitative analysis of the contributions of the potential drivers indicated that wind activity forced by different atmospheric circulation systems, rather than changes in vegetation cover, were the most important driver of regional aeolian activity, although their relative effects varied during the Holocene.

Consistency between the distributions for the two phases in aeolian sand transport: Impact of sand on wind

Consistency between the distributions for the two phases in aeolian sand transport: Impact of sand on wind

An equivalent analysis of unsteady sand transport in a wind tunnel

This study investigates the effect of unsteady wind on sand transport in a wind tunnel using sinusoidally varying wind velocity to represent the unsteady wind. By comparing sand transport fluxes under steady and unsteady winds, we demonstrate that cumulative sand transport flux varies sinusoidally with the sinusoidally varying wind velocity. In addition to the time-averaged wind velocity, the sand transport rate is also affected by the amplitude and period of wind velocity variations. We then propose an ‘equivalent’ steady aeolian sand transport process as a substitute for the actual unsteady transport process. In terms of wind velocity amplitude and period variations, an equivalent wind friction velocity factor u*′ is defined to capture differences caused by wind velocity variations with the same time-averaged wind velocity and friction velocity. Finally, a unified equation for aeolian sand transport is derived, demonstrating applicability for both steady and unsteady flow conditions. The results of this study contribute to a deeper understanding of aeolian sand transport under unsteady flow.

Spatial heterogeneity of sediments on a topographically diverse descending plate at convergent margins: An example from the outer slope of the Mariana Trench

Unraveling deep ocean sediment composition and its controlling mechanisms is crucial to understanding the interplay between the Earth's surface and the deep Earth. Convergent margins are generally featured by various seafloor landforms, but how submarine topography affects sediment accumulation processes remains poorly understood. Here we focus on submarine surface sediments from the outer slope of the Mariana Trench (covering water depths of 1218–6310 m) and combine microscopic observation, clay mineralogy, and elemental geochemistry to characterize sediment composition and to reveal physical, chemical, and biological sedimentary processes at topographically diverse convergent margins. Smear slide observations indicate that foraminifera shells dominate in shallow areas, while pelagic clays and diatom oozes prevail in trench and slope areas. Clay minerals primarily consist of illite (26–98 %) with low crystallinity index values and diverse chemical index values, followed by chlorite (0–45 %) and kaolinite (0–29 %). Smectite (0–61 %, 46 of 70 samples have smectite contents <5 %) of the samples from the outer slope area is low but appears dominant close to the trench. Bulk element compositions are mainly affected by the relative calcareous, siliceous, and lithogenous components that dissolved or accumulated inconsistently as submarine topographic feature changes. Our results imply that submarine topography and sediment provenance lead to significant heterogeneity of sediment composition at topographically diverse convergent margins. The submarine topographic relief, together with associated bathymetry and deep-sea circulation primarily controls carbonate deposition on the Caroline Plateau, and influences the sinking particles (including diatom shells and arc volcanic-sourced materials) accumulation in the trench basin. Continent-derived aeolian dust introduces illite-rich detritus, while localized volcanism potentially contributes to smectite-rich sediment in certain topographic provinces. We propose that the deep sea sedimentation processes in the Mariana convergent system are more diverse and complex than those at the margins with relatively plain topographic characteristics (e.g., the Japan Trench). The significant heterogeneity on descending plates along convergent margins may lead to various subduction behaviors. These findings contribute to a better understanding of deep ocean sediment source-to-sink systems and have implications for Earth's material cycle and multi-sphere interaction studies.

Eolian-fluvial succession in the Early Cretaceous from the Ordos Basin

Cretaceous eolian deposits are widely developed in North China, among which the Lower Cretaceous eolian (erg) sedimentary strata in the Ordos Basin are the most representative. Many studies have been conducted on eolian deposits in the Ordos Basin, especially the Luohe Formation; however, there is a lack of systematic sedimentology research and the corresponding research on the evolution of sedimentary facies. Therefore, to explore the Mesozoic drought events and the systematic evolution of the sub-tropical erg zone, this study reports the fluvial–eolian sedimentary sequences of the Early Cretaceous Luohe and Yijinhuoluo Formations in the Ordos Basin. Spatially, through detailed sedimentary lithofacies and structural analysis of different outcrops, the combination law of sedimentary facies can be determined. Based on this, a three-dimensional sedimentary model of erg is reconstructed. The erg environment is divided into three sub-environments: erg margin, erg margin–centre transition and erg centre. According to the evolution of the sedimentary facies, the sedimentary evolution from the Latef Jurassic to the Early Cretaceous in the Ordos Basin is divided into five stages. The Ordos Basin has experienced the delta, erg formation, erg deposition, erg shrinkage and evaporating salt-lake stages. The vertical sedimentary evolution indicates climatic oscillation in North China from the Late Jurassic to the Early Cretaceous. Under the control of the sub-tropical high belt, the Ordos Basin experienced a hot and arid climate during the Cretaceous, forming a widely distributed erg belt in the region. During this period, a small-scale climate shock occurred under the hot and arid background, changing the sedimentary environment.

Holocene aeolian-fluvial interactions patterns and their response to climate changes in the Paiku Co basin, Southern Tibetan Plateau

Aeolian-fluvial processes are crucial in shaping landforms. Despite the advancements in understanding the sedimentary processes of aeolian-fluvial interactions, the sedimentary patterns of these interactions are complex in spatiotemporal scale, and the records of Holocene small-scale aeolian-fluvial interaction sedimentary is insufficient, especially in the Tibetan Plateau region. Therefore, this study focuses on analyzing the sedimentary patterns of aeolian-fluvial interactions and their response to climate change in the Paiku Co basin of the southern Tibetan Plateau (TP). Through the examination of aeolian-fluvial sequences, Optically Stimulated Luminescence (OSL) dating is utilized to establish a chronological framework. Furthermore, proxy indices are explored to identify potential sediment models and their reactions to climate change. The findings indicate that fluvial activity predominated during a relatively warm and wet period around 5.1–4.6 ka, while thicker aeolian sands accumulated extensively during 4.6–4.1 ka as the climate transitioned to cold and dry conditions. On a millennial scale, the aeolian-fluvial interaction sedimentation is characterized by alternating deposition of clay layers and medium to fine sand. This sedimentation pattern is predominantly influenced by climate change. Overall, the findings shed light on the complex coupling between aeolian and fluvial processes in response to past climate changes, which has important implications for understanding the landscape evolution and environmental changes in this sensitive high-altitude region.

Latest Triassic Active Aeolian Dune Field Preserved by CAMP‐Related Lava Flows

ABSTRACTFieldwork investigations and stratigraphic analyses in the Parnaíba Basin, northern Brazil, reveal the interaction of the uppermost part of the Triassic Sambaíba aeolian dune field (erg) system with the latest Triassic–earliest Jurassic Mosquito lava flows. The lava flows originated as part of the Central Atlantic Magmatic Province (CAMP, ~201 Ma) and covered the aeolian system, allowing almost complete preservation of large‐scale in situ aeolian bedforms, even preserving lee‐ and stoss‐side. During the emplacement, the lava flows interacted with unconsolidated aeolian sediment, generating sediment–lava deformation features that are preserved at the interface between these units. This occurrence attests to arid conditions in the low latitudes of Gondwana at the Triassic–Jurassic transition.

Decoupling Distribution of n-Alkanes in Aeolian Sand and Vegetation of the Northern Ulan Buh Desert, China: Insight into Organic Matter Preservation in Arid Regions.

Fallen leaves and their decomposition directly deposit leaf wax n-alkanes into sediments, which can be used to identify local flora. These n-alkanes are important for studying past vegetation and climate, but their distribution in sediments must be known. Aeolian sand n-alkanes are particularly important for understanding paleoclimates in arid regions, despite the challenges of extraction due to their extremely low abundance. To investigate the preservation of plant leaf wax n-alkanes in deserts, we analyzed n-alkanes in aeolian sands from the Northern Ulan Buh Desert (UBD), China, and compared them to the surrounding vegetation. We calculated the total n-alkane concentration (ΣALK), average chain length (ACL21-35), and carbon preference index (CPI21-35). In the Northern UBD, aeolian sand n-alkanes have lower ΣALK, indicating microbial degradation. The eastern aeolian sand has lower CPI21-35 and ACL21-35 than the adjacent vegetation, whereas the western sand values are consistent with the plants, likely due to the transport of plant-derived materials by wind and water from the nearby mountains. Our study shows that sedimentary n-alkane signatures are not only determined by local vegetation but also influenced by environmental factors like temperature and precipitation. Additionally, local deposition processes play a significant role in determining the properties of these n-alkanes.

Aeolian sand cover on a granite peninsula (Hammeren, Bornholm, Baltic Sea) formed in three episodes during the past 11,600 years

Aeolian sand covers a significant part of the granite peninsula Hammeren on northernmost Bornholm in the Baltic Sea. The coastline of Hammeren is rocky and apart from one relative wide and sandy pocket beach at the east coast only few, small and gravelly pocket beaches exist. The aeolian deposits form three sand covers that stretch inland from the east and northwestern facing coasts of Hammeren. The largest sand cover forms a rising sand plain that cover the granitic landscape up to 700 m inland and reaches up to 60 m above sea level. Historical sources mention aeolian sand movement around CE 1775 in the middle of the Little Ice Age, but until this study no absolute age control has been available to confirm these observations. Luminescence dating of selected sample sites indicates that aeolian sand movement took place in three episodes. The first episode was in the last part of the Younger Dryas at about 11,500 BP, the second episode was in the Danish Late Bronze Age at about 2700 BP, and the youngest episode was indeed during the Little Ice Age around 200 BP (CE 1750). These episodes with aeolian activity all fall during relatively cold climatic intervals and add support to previous studies indicating a link between cold climates an increased storminess in Northwest Europe including the southern Baltic Sea region.

Character and Evolution of Sunken Groundwater-Harvesting Agroecosystems in Aeolian Sand since Early Islamic Times, between Iran and Iberia

ABSTRACT By reviewing traditional, sunken, groundwater-harvesting agroecosystems (SGHAS) in coastal and inland aeolian sand situated in Iran, Egypt, Gaza Strip, Algeria and Iberia, coupled with image interpretation and geospatial analysis, we study the innovation and function of recently excavated Early Islamic (EI; tenth-twelfth century), Plot-and-Berm agroecosystems along the southeastern Mediterranean coast of Israel. The SGHAS and EI agroecosystems, usually affiliated with nearby towns, possess an aeolian sand substrate enrichened with urban refuse and/or organic material. The long-term investment in SGHAS attained profitable water security in the form of temporally continuous, shallow groundwater, replenished by rainfall. The crops in SGHASs include a wide range of vegetables, watermelons, dates and grapes, implying that the EI crops were partly or fully different. The spotty, historic appearance of SGHAS since the fifteenth–sixteenth centuries temporally lags after the abandonment of the EI agroecosystems, does not support spatial and temporal connectivity of sand agriculture knowledge, but probably exemplifies the appearance of site-specific ingenuities derived from growing agro-technological knowledge, crop variety and needs for food security. This study demonstrates the importance of traditional analogues for interpreting research gaps of archaeological, agricultural landscapes and provides insight for establishing traditionally-based, sustainable agriculture in sand.

A Regional Paleoclimate Record of the Tropical Aeolian Sands during the Last Deglaciation in Hainan, China

The KLD segment of the Kenweiyuan section in Wenchang, Hainan, China is a set of aeolian sand deposits of the Last Deglaciation. The chemical element and heavy mineral analysis performed in this study reveals the chemical index of alteration (CIA) in the segment to be as high as 93–95, with all the heavy minerals identified as stable and extremely stable making up 38–45% of the total. Furthermore, the zircon, tourmaline, and rutile content (ZTR index) of the segment is determined to range between 48–71. The (Al2O3 + TOFE)/SiO2 ratios display obvious fluctuations from old to new strata in the segment, with the low values corresponding to Heinrich event (H1), Dansgaard-Oeschager (D-O), and Younger Dryas (YD) and the high values corresponding to Bølling and Allerød. Our study suggests that these fluctuations are attributed to the alternation of the East Asian winter and summer monsoons. Hainan Island is also impacted by the surface ocean climate of the South China Sea, and characteristics of the KLD segment may be connected to the climate changes in the North Atlantic related to the winter monsoon season or westerlies. Furthermore, the segment presents a clear response to millennium-scale climate changes during the Last Deglaciation on Hainan Island. Based on the high CIA values in the KLD segment, and particularly due to the observed stable detrital minerals, the ratios can be linked to the overall tropical climate, indicating a relatively warm tropical climate environment in the Last Deglaciation in Hainan. The high CIA values also reveal the cause of aeolian sand formation under the tropical environmental conditions in the low latitude region of China in the Late Quaternary.

Enhancing aeolian sand stability using microbially induced calcite precipitation technology

This study investigates the effectiveness of Microbially Induced Calcite Precipitation (MICP) technology in enhancing the stability of aeolian sand. Applying MICP to desert sand samples from Kashi, Xinjiang, the results demonstrated significant structural stability and erosion resistance in treated soils during wind erosion tests. Particularly after 14 days of treatment, the soil samples exhibited optimal wind erosion resistance and surface crust strength. Additionally, the formation of calcite significantly improved the soil’s penetration strength and wind erosion resistance, with SEM analysis confirming that calcite “bridges” between soil particles enhanced inter-particle bonding. Environmental impact assessments indicated that MICP technology is not only environmentally friendly but also effectively reduces the risk of soil environmental pollution. These findings validate the potential application of MICP technology in enhancing the stability and environmental adaptability of aeolian sand.

Speculation on an early Pleistocene origin of the Parker dunes of southwest Arizona, USA

The Parker Dunes in western Arizona, USA represent the largest dune system in the Sonoran Desert. This study presents a simple 10Be-26Al cosmogenic burial age of 1.90 ± 0.20 Ma, obtained from well cuttings 240–270 m deep in Butler Valley, just east of the dune field. Given the large errors associated with burial dating, we can only speculate that this oldest known aeolian sediment within the Parker Dunes is roughly concurrent with the Bat Cave flood event ca. 2.1 Ma of the nearby Colorado River, as well as regional climatic aridity during the early Pleistocene. Since older dune deposits may be present at other locations in the Parker Dunes, its origin dates back to at least the early Pleistocene. The more important, broader implication rests in highlighting the underutilized potential of well cuttings as a sediment source for cosmogenic burial dating in aeolian research.

Bending properties and damage evolution of fiber-reinforced aeolian sand backfill materials

Backfilling is a promising measure for controlling surface subsidence in mined-out areas and disposing solid wastes from the mineral processing, there are increasing demands of enhanced toughness and anti-cracking properties of backfill materials to prolong the service life under the complex loads. In this study, polypropylene (PP) fibers were employed to improve performance of backfills, four-point bending and uniaxial compression tests were conducted to investigate the failure process and damage evolution of fiber-reinforced aeolian-sand backfill materials (FABs) using Digital Image Correlation (DIC) and Acoustic Emission (AE) techniques. The results show that the compressive strength tends to decrease with the increasing fiber volume fractions, while the four-point bending strength shows a tendency to increase initially and then decrease, and the optimum volume fraction of PP fiber is 0.6%. At the optimal fiber volume fraction, PP fibers with lengths of 3 mm and 9 mm resulted in a 65.25% and 81.62% increase in the four-point bending strength of FABs, respectively. As indicated by DIC measurements, PP fibers with a length of 9 mm were more effective in controlling the horizontal and vertical displacements of FABs under four-point bending loads than that of 3 mm, and the cracks developed more slowly at the same deflection. In addition, PP fibers with a length of 9 mm have stronger crack extension delay characteristics due to longer effective anchorage distance, as evidenced by more frequent acoustic emission ringing counts and higher cumulative ringing counts. The results of the study may provide a theoretical basis for the application of FABs materials in backfilling.

Effects of cement content, polypropylene fiber length and dosage on fluidity and mechanical properties of fiber-toughened cemented aeolian sand backfill

Effects of cement content, polypropylene fiber length and dosage on fluidity and mechanical properties of fiber-toughened cemented aeolian sand backfill

Evolution and hydro-stratigraphy of the coastal aquifer in Garopaba/SC: Interpretation from georadar and tubular wells

This work analyzes the geological evolution of sedimentary deposits in the coastal aquifer of Garopaba, south Brazil, using ground penetrating radar (GPR) and data from tubular wells. The aquifer is localized in the coastal plain, where Quaternary lagoon-barrier environments are set between the Precambrian crystalline mountains and the sea. Over ten tubular wells are scattered in urbanized areas, which highlights the vulnerability of the unconfined, granular shallow aquifer. The results show that the aquifer has lithologic units of local scale. Tubular well data show the basal limit of the aquifer overlying clayey layers between 30 and 40 m deep and intercalation of sand layers up to the surface, mostly fine to very fine sand, with metric thickness, secondary lenses of clay and minor occurrence of gravel. The radarfacies interpretation shows fluvial-estuarine deposits as a local hydrostratigraphic unit, with lateral accretion bars filling a NE-axis paleochannel. The basal surface of the channel is interpreted as the sequence boundary surface of the lagoon-barrier systems III (upper Pleistocene) and IV (Holocene). The geological evolution of the aquifer is related to the upper Pleistocene marine regression (120–18 ka), that caused the aerial exposure of the continental shelf, and the development of complex drainage channels, which were superimposed during the Holocene transgression by lagoon-barrier IV deposits. After the post-glacial transgression, the lowering of the RSL to the current level promoted the silting of part of the lagoon system by continental sedimentation and aeolian deposits composing the surface.