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Eastern Central Asia has an arid environment and experiences frequent dust storms. Modern observations indicate that the dust storm frequency in eastern Central Asia is modulated mainly by the intensity of the Siberian High (SH). However, a lack of knowledge about the process influencing the variation of the SH limits our ability to understand the genesis of dust storms and their predictions. In this study, we present data on heavy mineral assemblages and sediment grain size in a loess section in eastern Central Asia, spanning the last glacial. Combined with previously published results, we propose that the sorting coefficient in loess‐paleosol sequences is a more sensitive proxy for wind intensity—and thus for the intensity of the SH—than the commonly used proxies of the mean grain size and grain size fractions, which are also influenced by changes in dust source and vegetation cover. Our sorting coefficient series clearly reveals Heinrich events, as well as the prominent ∼5 kyr Bond cycle. Larger sorting coefficients correspond to more depleted Sanbao Cave stalagmite δ18O values, revealing an antiphase relationship between the intensity of the SH and the East Asian Summer Monsoon during the last glacial. The sorting coefficient series also support the significant influence of Arctic sea‐ice cover on the intensity of the SH. Plain Language Summary: Central Asia is characterized by an arid environment. Dust storms occur frequently in Central Asia. Modern observations indicate that the frequency of dust storms in eastern Central Asia is mainly related to the near‐surface wind intensity, which is modulated by the Siberian High (SH). Therefore, understanding the change process of the SH intensity and its driving mechanism is helpful to effectively predict dust storms in the future. Bulk grain size proxies, such as mean/median grain size or grain size fraction, are usually used to reflect changes in the intensity of the SH, but they will also be affected by other factors such as vegetation coverage and dust provenance. In this study, we first theoretically discuss the potential of sorting coefficient as an indicator of near‐surface wind intensity. The sorting coefficient is then applied to a Central Asian loess section to infer the variation of the SH intensity. In contrast to commonly used mean grain size, sorting coefficients not only clearly reveal Heinrich events but also demonstrate very strong ∼5 kyr cycles, known as the "Bond Cycle". Larger sorting coefficient corresponding to more depleted Sanbao cave stalagmite δ18O values indicates an antiphase relationship between the SH and East Asian Summer Monsoon during the last glacial. Key Points: Sorting coefficient is a more sensitive proxy for wind intensity than commonly used proxies of mean grain size and grain size fractionAntiphase relationship between the Siberian High (SH) and East Asian Summer Monsoon during the last glacialOur results support the great influence of the extent of Arctic sea ice on the intensity of the SH [ABSTRACT FROM AUTHOR]

The Tuoji II (TJII) section on the Miaodao Islands in the Bohai Sea is a representative aeolian section off China’s east coast. This study applied optically stimulated luminescence (OSL) dating, conducted grain size analysis, and examined major and trace element compositions, to investigate the loess–paleosol sequences. The OSL ages at depths of 0.6, 1.8, 2.8, 3.8, and 4.8 m were determined as 14.4 ± 0.4, 16.7 ± 1.3, 20.8 ± 1.0, 40.9 ± 1.5, and 47.9 ± 3.7 ka, respectively. It was projected that the loess started to accumulate at ca. 62.6 ka, according to presumed depositional rates. In this study, typical aeolian deposits elsewhere including the Luochuan (LC), Xiashu (XS), Wushan (WS), and Xifeng (XF) sections were compared with TJII section here. The results showed similarity in the geochemical characteristics of the deposits from the different areas of China and normalized upper continental crust, indicating aeolian origin of this island loess. In comparison with the LC, XS, WS, and XF samples, the aeolian deposits of the TJII section have higher concentrations of TiO 2 and Zr and lower concentrations of Al 2 O 3 , Rb, and Ni, and they have higher SiO 2 /Al 2 O 3 and TiO 2 /Al 2 O 3 ratios and lower Al 2 O 3 /Na 2 O and Ba/Sr ratios. These features indicate the dust materials of the TJII section were derived from local sources of well-mixed sedimentary protoliths. Our results support the suggestion that paleoclimatic change and the evolution of aeolian sediments were controlled primarily by variation of the East Asian summer monsoon and sea level change. [ABSTRACT FROM AUTHOR]

The confirmation of an eolian origin of the Tertiary ‘Red Clay’ from North China would make it a valuable terrestrial paleoclimatic record. However, it is still controversial as to which wind primarily transported the dust forming the ‘Red Clay’ onto the Loess Plateau. Careful consideration of this question is a prerequisite for better understanding the history of atmospheric circulation in central and East Asia during the Miocene and Pliocene epochs.In this paper, the grain-size distributions of bulk samples and chemically isolated quartz grains of the Late Tertiary ‘Red Clay’ were investigated to explore the potential transportation mechanisms of the dust as well as the atmospheric circulation at the time of deposition. The samples were taken from six localities spanning across 550 km on the Loess Plateau.The results show that the mean grain size of both bulk and quartz samples decreases southward, as does the coarse fraction content (>42 μm). These data not only give new evidence for the eolian origin of the ‘Red Clay’, but also indicate that the ‘Red Clay’ was probably transported mainly by northerly low-level winds, or the winds at least had a strong northerly component. Therefore, the spatial distribution of grain size of the ‘Red Clay’ is comparable to that of the overlying Quaternary eolian loess, which demonstrates a remarkable northwest–southeast decrease in grain size, sedimentation rate, and thickness during the Last Glacial, coinciding with the dominant wind direction of the northwesterly East Asian winter monsoon. However, the grain size of the ‘Red Clay’ is generally finer than the corresponding loess. This indicates that the ‘Red Clay’ may have been transported by a weaker winter monsoon associated with stronger pedogenic modification, and/or the dust source area was not extensive compared to that during the Quaternary. Moreover, the high content of grains coarser than 19 μm, transported mainly by energetic low-level winds over short distances, suggests that the dusts were not transported by upper-level westerly. [Copyright &y& Elsevier]

Coastal loess is a unique and intriguing eolian sediment on Earth, but understanding its formation time, provenance, composition and the geomorphic processes that resulted in its accumulation is very limited compared to its inland counterpart. In this paper, we focused on a loess section at Xiazhupan (XZP) Village, Penglai City in Shandong Peninsula, the only known coastal loess bluffs preserved in China. The coastal loess here not only has characteristics that are common to loess terrains such as being composed of predominantly silt-sized particles and the tendency to stand in vertical exposures, but it also reportedly preserves planktonic foraminifera, sizable pebbles and volcanic glass. In addition to its peculiar near-shore locality, these features make it more unusual compared to other loess deposits. Systematic optically stimulated luminescence (OSL), infrared stimulated luminescence (IRSL and pIRIR) and radiocarbon dating reveal it was deposited mostly during 60–20 ka, Marine Isotope Stage (MIS) 4-2, which correlates to the deposition of the Malan loess (L1) in the Chinese Loess Plateau. High-resolution grain size data indicate that the coastal loess is relatively coarse-grained, suggesting a source terrain that is at least partially proximal. Given its proximal source and the geochronological evidence, this coastal loess was sourced from the exposed continental shelf during the sea-level lowstand of the last glacial period, and this hypothesis is further supported by a core collected from the Bohai Sea in which silt was present and would have been subaerially exposed during MIS 4-2. In addition, this source area of exposed continental shelf is comparable to coastal loess in Europe. The coastal loess in Shandong can be regarded as a special type of desert or dryland loess, rather than glacial loess. Finally, future sea level rise will likely increase the erosion potential of these vulnerable coastal loess bluffs, making it urgent to study this special landform. [ABSTRACT FROM AUTHOR]

Many lakes in the Qinghai-Tibetan Plateau (QTP) have aeolian sands distributed in their downwind shores. However, it has been rarely systemically investigated on whether the downwind dune sand and lake evolved in association with each other or they evolved independently. Here we take the well known Qinghai Lake and its downwind sand area as a case study to investigate the issue of water-sand interaction. Grain size, magnetic susceptibility and geochemical data along with optically stimulated luminescence (OSL) ages suggest that the downwind eastern shore sandy lands co-varied with the lake level fluctuations (or lake extension changes) of the Qinghai Lake during the Holocene epoch. During the early Holocene lake lowstands (11-9 ka, ka is 1000 years), vast areas of exposed lacustrine sediments were eroded by prevailing westerly winds, therefore, causing sand to accumulate at the eastern shore bajada areas along the west piedmonts of the Riyue Mount, and to expand along the Daotang River valley. In contrast, during the mid to late Holocene lake highstands (7-1.2 ka), eastern shore dune sands were largely stabilized, and loess accumulated and even paleosol developed, leading to substantial shrinkage of the eastern shore sandy lands. In addition, using GIS tool, we reconstructed the spatial extensions of the lake during highstand (Mid-Holocene) and lowstand (Early Holocene), and eastern shore desert range of early Holocene. As a result, this study indicates a close connection between the lakes in QTP and the aeolian sands downwind. [ABSTRACT FROM AUTHOR]

The accumulation processes of loess in Shandong Province record atmospheric circulation changes in eastern China, which can be used to explore the varying characteristics of the East Asian monsoons and the evolution of the local environment. In this study, parameterized grain size endmember analysis is used to reveal the characteristics of sedimentary dynamics, material sources, and environmental evolution of a loess profile in Focun, Zibo City, Shandong Province, China. Optically stimulated luminescence (OSL) ages of the profile ranged from 3.02 ± 0.45 ka to 100.99 ± 13.58 ka. The grain size components of the sediments in the profile were divided into five endmembers. EM1 represents a mixed clay component of pedogenesis, EM2 represents a fine silt component transported by high-altitude westerlies, EM3 represents material that settled in the form of floating dust, EM4 represents a silt component transported by low-altitude near-source areas, and EM5 represents short-distance suspended materials transported under dust storms. Combined with a low frequency magnetic susceptibility (χ lf) and chromaticity (a⁎), the characteristics of grain size endmembers indicate changes in sedimentary environments since the last interglacial (MIS 5). In MIS 5 the winter monsoon accumulation was low, with high accumulation during the summer monsoon, and an unstable climate. In MIS 4 the winter monsoon produced high accumulation, with low accumulation during the summer monsoon, and frequent dust storms. In MIS 3 the winter monsoon accumulation was low, westerly circulation and summer monsoon accumulation were high, and the climate was warm and humid. In MIS 2 the winter monsoon accumulation was high, summer monsoon accumulation was low, and the climate was dry and cold. In MIS 1 the westerly circulation and winter monsoon accumulation were low, summer monsoon accumulation was high, and the climate was warm and wet. This reflects the regional response to global climate change. This study shows that the parametric grain size endmember analysis method is feasible in studying the sedimentary dynamics, material sources and sedimentary environment of loess in Shandong Province. • Typical loess-paleosol sequence in Shandong Province, Eastern China. • Parametric grain size endmember analysis (EMMA). • The material composition is mainly near source. • The dynamic sedimentary conditions include pedogenesis, westerlies, dust fall, winter monsoon and dust storms. • The environmental evolution since the last interglacial (MIS5) in Shandong Province and its regional response to global climate change. [ABSTRACT FROM AUTHOR]

Loess deposits of the central Great Plains, USA, and their intercalated soils provide a detailed record of climatically driven changes within the aeolian system during the Pleistocene-Holocene transition and the Holocene. Here we present a detailed optically stimulated luminescence (OSL) chronology as well as multi-proxy analysis obtained for the first time on the Enders section, located in southwestern Nebraska, central Great Plains. The section records multiple episodes of rapid loess deposition alternating with soil formation. Rapid accumulation of Late Pleistocene Peoria Loess was replaced around 13–14 ka by formation of the Brady Soil until 9.5 ± 0.6 ka. The Holocene Bignell Loess then buried the Brady Soil and accumulated episodically throughout the Holocene. The loess-paleosol stratigraphy since the Late Pleistocene at the Enders site is very similar to that at other sites in western Nebraska, and the newly developed OSL chronology (based on three grain size classes) adds new confidence to earlier dating. The high-resolution grain size profile from Enders shares many features with similar data from the previously studied Wauneta site, including three peaks of fine-grained material just above and within the Brady Soil, likely representing response to millennial-scale climatic changes during the Pleistocene-Holocene transition. This study demonstrates the potential for developing high-resolution, well-dated paleoclimatic records from the loess of the central Great Plains. Contrasts between Great Plains and Eurasian loess records reflect differences in the Late Pleistocene to Holocene climatic evolution and other factors influencing the loess system. • Multi-proxy paleoclimatic record obtained from loess sections of Great Plains, USA. • New multi-method OSL dating adds confidence to Great Plains loess chronology. • Brady Soil (12.7 ± 0.8–9.5 ± 0.6 ka) buried by episodic Holocene loess deposition. • Isotopic analysis of carbonates in this loess may provide paleoclimatic records. • Contrasts with Eurasian loess reflect regional variation in climate evolution. [ABSTRACT FROM AUTHOR]