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Central Yakutia is a large region in northeastern Siberia characterized by extensive permafrost, large river valleys, mountain glaciers, and large massifs of aeolian sands; the geological history of the region is complex and, at present, poorly constrained. In recent years, it has been shown that aeolian sands cover up to 60% of large parts of Central Yakutia. This paper presents the results of luminescence dating of aeolian sedimentation at the Diring Yuriakh Palaeolithic site located in the middle reaches of the Lena River. Field studies identified several thick units of aeolian sand, which cover an old deflation surface with Late (Duktai culture) and Early Palaeolithic (Diring culture) artefacts. The reliability of the OSL chronology was assessed by comparison of ages based on the optically stimulated luminescence from quartz and the infra-red stimulated luminescence from potassium-rich feldspars; these age pairs are in good agreement, implying that at least the quartz grains were sufficiently bleached before sedimentation. We obtained OSL ages that reflect three periods of accumulation between the LGM and the Holocene: ∼21 ka, 15-14 ka, and 12.5–10 ka. These periods of accumulation broadly coincide with global cooling episodes during the Last Glacial Maximum, the Older Dryas, and the Younger Dryas, with some extension into subsequent warmer intervals, whereas the intervening intervals without preserved sediments are taken to reflect dune stability during warmer periods. The sand on the terraces, sourced from alluvial bars in the river channel, was blown up the valley slope during cold and dry periods when the vegetation cover was sparse. When the climate warmed, the vegetation took some time to spread, and so the accumulation of aeolian sand on the high terraces continued into the warm periods. We also infer periods of deflation (wind erosion) that occurred before 21 ka and between 20 and 15 ka, presumably due to increased aeolian activity and localized remobilization of sediment. The new OSL chronology shows that the younger artefacts located at the cape of Diring Yuriakh, belonging to the Late Palaeolithic Duktai culture, are older than 15 ka. The new ages also show that the post-LGM aeolian sand sequences at Diring Yuriakh are correlated with the regionally developed subaerial Dolkuma Formation. [ABSTRACT FROM AUTHOR]

This paper addresses the surface and Holocene aeolian deposits in the southeastern Mu Us Desert, N. China, systematically analysing the evolution of the geochemical characteristics of aeolian sand-palaeosol sequences and their environmental significance. Our results indicate that the geochemical components of the Holocene aeolian deposits and surface deposits had the similar material sources, sediment transport and deposition processes in the study region, which were dominated by SiO2, Al2O3, and Na2O. In the weathering process of the Jinjie (JJ) profile, the Na, K, and Si presented the slight leaching and migration in general, while the other elements were relatively accumulated. The Holocene aeolian deposits and surface deposits incurred weaker geochemical weathering under cold and dry conditions and were only weakly leached, which implies a relatively arid environment in the Holocene epoch and the modern era. The weathering degree was controlled by the regional temperature and precipitation, and was probably more sensitive to the precipitation changes. In the sedimentary profile, the geochemical parameters and migration of elements demonstrated that there have been several alternating warm-wet and cold-dry intervals in the Mu Us Desert in the Holocene epoch; there were relatively warm and wet conditions prior to 4.6 ka, and it has been cold and dry since then. Six millennial-scale dry events were recorded during the Holocene, which were not only accordant with the history of palaeoclimatic changes in the different latitudes and archives of the Northern Hemisphere, but also correspond to the millennial-scale variation of cosmic radiation and solar activity during that period. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The Bagnold linear dune field investigated by Curiosity at Mount Desert Island (MDI) is north of the ∼5.5 km high Aeolis Mons mound in Gale crater. False‐color images (RGB: 2.496, 1.802, and 1.237 μm, respectively) generated from Mars Reconnaissance Orbiter Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) data show the dune field has a reddish‐brown color. The Sands of Forvie (SoF), located ∼2.5 km to the southeast of MDI, is darker and lacks the reddish‐brown color. Single scattering albedo (SSA) spectra retrieved at 12 m/pixel using along‐track oversampled CRISM observation FRT00021C92 show a long wavelength (1.7–2.5 μm) increase in albedo for MDI dunes. For the same wavelength interval, SoF is characterized by a broad ∼2.2 μm absorption feature, consistent with color differences between the two deposits. Checkerboard un‐mixing of the SSA image cube was used to isolate spectral endmembers within the MDI and SoF deposits. Radiative modeling of these CRISM spectral endmembers using Hapke (2012, https://doi.org/10.1017/CBO9781139025683) theory implies finer grain sizes, more pigeonite, plagioclase, and olivine, and less basaltic glass and augite for MDI as compared to the SoF deposit. These results are consistent with Curiosity‐based observations that MDI contains smaller ripples with overall finer grains, whereas SoF has large ripples with coarser grains on the crests. Although these sand deposits are only located ∼2.5 km away from one another, wind and local topographic controls are interpreted to have modulated grain sizes and mineralogy. Plain Language Summary: "The present is the key to the past" is a fundamental tenet of geological sciences. Studying modern‐day, active processes and products provides important insights into interpreting the ancient rock record. Previous studies using orbital imaging data and rover‐based observations show that wind‐blown sand deposits occur in many locations and cover a variety of ages in Martian rock records. Thus, study of modern Martian sand deposits is an important element for understanding the processes that produced ancient deposits in addition to providing information about the modern depositional environments. To that end we have pursued advanced processing of hyperspectral imaging data covering two separate, modern sand deposits that were visited and characterized by the Curiosity rover. We show that the Mount Desert Island (MDI) linear dunes, located in the large Bagnold dune field, have different mineral abundances and smaller grain sizes than the Sands of Forvie (SoF) sand sheet. These differences result, at least in part, from the competing processes of unconstrained dune migration (MDI) and topographically inhibited sand migration (SoF). This is the case even though the two deposits are the same age and only ∼2.5 km away from one another, thereby providing an important lesson for interpreting the ancient rock record. Key Points: Data show that modern sand in Bagnold dunes and Sands of Forvie (SoF), only ∼2.5 km apart, have different mineral abundances and grain sizesBagnold sand has finer grains with more pigeonite, plagioclase, olivine, and less basaltic glass and augite versus SoF sandThese differences result from unconstrained Bagnold sand migration as opposed to topographically inhibited migration in the SoF [ABSTRACT FROM AUTHOR]

Surface sediments such as aeolian sand, loess/sandy loess, and fluvial/alluvial clastics are widespread in the Yarlung Tsangpo (YT) catchment and across the Tibetan Plateau (TP). However, it is debated whether the source of the aeolian sediments is local or remote, involving transport across large regions, and whether the surface sediments, especially aeolian deposits, are a major source of global dust. Here, we use strontium‐neodymium (Sr‐Nd) isotopic analysis and modern observations of dust emissions to investigate the provenance of aeolian sediments from the YT catchment and adjacent areas during different periods (modern, Holocene, Late Pleistocene), and the relationship between surface sediments of the TP and the dust component of sediments in the Japan Sea and the North Pacific Ocean. Strontium‐87/strontium‐86 (87Sr/86Sr) and neodymium isotopic ratio (εNd) show a wide range of variation in different areas (87Sr/86Sr varies from 0.707996 to 0.731078, and εNd from −6.2 to −13.6), influenced by the composition of the clastic material derived from the local parent rock; additionally, there are no significant variations between size fractions. Due to local recycling the aeolian sedimentary systems in the southern TP are supplied with clastic material from proximal sources, and they are unlikely to receive large quantities of long‐range dust transported from regions such as the Taklimakan desert in Central Asia. Dust emission occurs mainly in the dry season (from March to May) and the dust is carried on the upper‐level westerly jet stream and then deposited downwind in the Japan Sea and the North Pacific Ocean, thus contributing to global dust. [ABSTRACT FROM AUTHOR]

Lakes provide high-sensitivity and high-resolution documents and evidence, which are required for studying climatic changes and sedimentary environments at the global level. Furthermore, aeolian deposits in lacustrine environments, because of recording drought periods and dust storms, are valuable archives of paleoenvironmental conditions. In the present study, besides collecting the previous data, it was attempted to sample three intact sedimentary cores with the maximum depth of 7.3 m and total depth of above 20 m, from the sediments of the lakebed by auger. Sedimentary facies were separated based on their color, grain size; sedimentary composition, grain shape, and type of evaporate minerals. The existence of brown-colored coarse-grained pneumatic sand particles during the early to mid-Holocene period (8.2 ka BP) indicated the occurrence of intense storms in Sistan Basin. Sequence of the fine- and very fine-grained pneumatic sands at the depth of 2.5 m represented the presence of the winds similar to the current "120 day winds" in Sistan plain. Moreover, in this study, two major drought periods (8.2 and 4.5 ka BP) were identified in Holocene sediments of the lakebeds of Hamun-e-Helmand and Hamun-e-Sabari, which indicated drying and expansion of the aeolian sediments on Hamun's lakebed. [ABSTRACT FROM AUTHOR]

• An extensive and inactive inland dune field has been identified in southern Italy. • Dune sands are coarse-grained, moderately sorted, positively skewed and mesokurtic. • Quartz and minor feldspars dominate sand petrographic composition. • Typical wind-generated features of sand grains were displayed by SEM analyses. • The dune field was active during the period going from 28 ka to VI-IV century B.C. Geomorphological investigations coupled with sedimentological, petrographical, and SEM analyses allowed to identify, for the first time, a paleo-fixed and inland aeolian dune field in the Gioia Tauro Plain, on the Tyrrhenian side of southern Calabria (southern Italy). The aeolian landforms, extended over an area of 43 km2, are characterized by smoothed and elongated NW-SE trending vegetation-fixed linear dunes, varying in height from a few meters up to 20 m. Forty sand samples were collected from dunes to perform laboratory analyses. Grain size analyses showed that samples are composed of unimodal coarse-grained sands (Mz = 0.820 φ), moderately sorted (σ = 0.862), positively skewed (Sk1 = 0.173) and mesokurtic (KG = 1.115). Petrographic analyses highlighted a composition dominated by quartz and minor feldspars. Modal data, and especially the high F/Q ratio and the Rg:Rs:Rm triangular plot, suggest a plutoniclastic supply from the Aspromonte Massif crystalline source rocks. SEM analyses of sand grains clearly displayed the presence of typical wind-generated features mainly represented by rounded form with low relief, bulbous edges, and dish-shaped depressions. These results combined with morphological analyses showed that these aeolian deposits fall into the category of sand sheets. Furthermore, geological and geoarchaeological data evidenced that dune field was formed in the time interval between ~28 ka and the VI - IV century B.C. The dune filed formation has been interrupted presumably by the combined effect of Holocene tectonics, along the Gioia Tauro-San Ferdinando normal fault, and the lowering of sea level, during the Last Glacial period, originating a natural barrier to windblown sand particles. The findings of the paper will help in understanding both inland aeolian products in southern Europe associated to the second colder phase of the Last Glacial period in the Mediterranean area and the complex patterns of spatial and temporal distribution, as well as the control factors determining preservation of the aeolian sediments throughout the rock record. [ABSTRACT FROM AUTHOR]

The Wahiba Sand Sea is a north-south aeolian field that occupies the northeast corner of the Sultanate of Oman. Two main phases of sand dunes are conspicuous in this dune field as revealed by satellite data, namely High Sands in the north and Low Sands in the south. They are completely different in grain color and dune morphology. Granulometric and mineralogical analyses of sediments reveal more than a single source of sand supply for the two regions. Linear dune belts cover the northern dune field and complex transverse ridges predominate at the southern area. Hourly wind data from two meteorological stations at Ibra and Masirah in the north and south of the sand sea, respectively, were collected for 11 years (Jan. 2000 to Dec. 2010) in order to calculate the seasonal and annual sand drift potential along the sides of the sand sea. Results showed that wind energy is extremely high at Masirah due to the SW summer and fall monsoons, whereas at Ibra, wind energy is very low. The drop of sand drift potential (DP) from south to north is clearly observed from analyzing sand moving winds by empirical equations. The morphology of dunes and the direction of sand drift potential suggest two dune fields in the sand sea. The current pattern of wind regime in the north is presumably different from the prevailing wind during dune formation, whereas the dunes in the south were significantly formed by the recent wind regimes. This observation implies that two connected dune fields constitute the Wahiba Sand Sea. [ABSTRACT FROM AUTHOR]

The northeastern Qinghai‐Tibetan Plateau (QTP) of China is located at the triple junction of the Asian winter and summer monsoons and the westerlies, where paleoclimatic evolution has an important scientific significance for recognizing the spatial‐temporal pattern of Asian monsoons in the past and predicting environmental change in the future. Nevertheless, the framework of the Holocene moisture variation and related mechanisms remain controversial, owing to complex hydroclimatic conditions triggered by the landform of the large mountain‐arid basin. Here, we employed geochemical proxies from typical aeolian sand‐palaeosol sequences in the Gonghe Basin, northeastern QTP, together with Optically Stimulated Luminescence (OSL) dating, to reconstruct the pattern of effective moisture variation and associated mechanisms in this region. Our results indicate that the regional effective moisture was at its lowest until 9–8 ka, and approached a maximum during 8–4/3 ka of the middle Holocene. Afterwards, the climate became relatively dry in general, but with a transient humid interval around 2–1 ka. Our geochemical evidence indicates that the dry early Holocene probably can be attributed to a strong winter monsoon forced by remnant ice sheet, combined with the high evaporation caused by solar insolation. Also, shifts of humid‐dry are closely linked to the Asian summer monsoonal strength and therefore the balance of evaporation‐precipitation in the middle and late Holocene. Thus, the pattern of the Holocene effective moisture variation is characterized as the 'monsoon model' in a closed intermontane arid and semi‐arid basin near the western Asian monsoonal limit. [ABSTRACT FROM AUTHOR]

The record of the Holocene millennial‐scale climate variations from the aeolian deposit around the monsoonal boundary zone in northern China is poorly understood because the desert sediments are usually scattered and geological archives are discontinuous. Here, we conducted magnetic, sedimentological, and geochemical analyses of the palaeosol‐aeolian sand sequence from the eastern Horqin dune field in northeastern China, which documented the detailed history of climatic variations during the past 7.0 ka. The results indicate that the climate became more humid around 7.0−5.0 ka and approached an optimal humid condition around 5.0–3.6 cal ka BP. Afterward, the moisture condition clearly declined in 3.6–1.3 cal ka BP and was replaced by dry climate at the end. Additionally, we discovered that 10 periodically dry events that punctuated the overall pattern of climatic variations in the region, with times of more than 7.0, 5.7–5.5, 5.5–5.0, 4.6–4.2, 4.2–3.7, 3.6, 3.5–3.3, and 1.3 cal ka BP. These intervals were not only very consistent with the dry/cold events in the monsoonal boundary zone of northern China, owing to weak summer monsoonal strength forced by solar radiation, but were also accordant with the increased Asian winter monsoon strengths induced by environment variations of the high latitude area. This phenomenon probably implies the antiphase relationship between Asian summer and winter monsoons on the Holocene millennial‐scale around the monsoonal boundary zone of northern China. [ABSTRACT FROM AUTHOR]

The palaeosol-loess-aeolian sand sequence in the eastern Gonghe Basin, which is located at the convergence of the Asian summer monsoon, winter monsoon and the westerlies, reveals detailed moisture changes in the northeastern Qinghai-Tibetan Plateau (NETP) during the last 17 ka. Analysis of magnetic susceptibility (MS), total organic carbon, carbonate content, grain size and geochemical parameters indicate that the region was dominated by an extremely dry climate during ~17.0-15.82 ka, accompanying large-scale desert expansion in the last glacial maximum (LGM). Subsequently, the climate became generally dry during 15.82-14.6 ka, an interval in which loess rapidly accumulated. Enhanced humidity occurred at 14.6 ka, probably associated with increased strength of the East Asian summer monsoon. The region experienced slightly decreased moisture at around 6.5 and 5.8 ka. After 2.7 ka, the climate became wetter. This interpretation correlates with climatic records from lacustrine and aeolian deposits in the NETP during the LGM, the last deglaciation and the early-middle Holocene. High climatic moisture in the Late Holocene facilitated the formation of a well-developed palaeosol in the NETP. The effective moisture change in the Gonghe Basin is not simply ascribed to the influences of Asian summer monsoons; instead, it was possibly influenced by the interaction of evaporation and monsoonal precipitation forced by solar insolation variation. The balance between these variables was very influential on the effective moisture change in the closed inland basin of the NETP. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

During Early, as proposed by the International commission on stratigraphy Pleistocene times, interacting fluvial and aeolian processes constructed wide alluvial plains over an evaporite-dominated Miocene substratum in the central Ebro Basin. An exceptional site where these deposits show faults, folds, diapirs, karst structures and unconformities has been studied in detail. Analysis of particular structures demonstrates the interaction by that time of tectonic faulting, diapirism, karstification and sedimentation in an area where deformation was traditionally linked to the presence of underlying evaporites, without proposing any precise mechanism. Multiple approaches (sedimentology, structural geology and geophysics) have been used in order to discriminate the origin of each type of structure as well as to understand the interaction between different processes. Numerous normal faults and fractures of variable size are consistent with the regional stress field. Pleistocene deposits are pierced by diapirs of Miocene evaporites and disrupted by karst structures with different geometries (tubular, funnel and vault), both partially controlled by tectonics. The example described is proposed as an analogue model that could successfully illustrate evolution patterns of basins of potential interest for petroleum geology where similar processes have actuated, resulting in complex stratigraphical architectures. [ABSTRACT FROM AUTHOR]