Geochemical evidence of the sources of aeolian sands and their transport pathways in the Minqin Oasis, northwestern China

Ren, Xuemei; Yang, Xiaoping; Wang, Zhenting; Zhu, Bingqi; Zhang, Deguo; Rioual, Patrick

doi:10.1016/j.quaint.2014.04.037

Cited by 27 publications

(42 citation statements)

References 67 publications

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“…The reason is that for aeolian sediments, the differences in compositions and distributions of rare earth elements and other trace elements in different samples/sub-fractions are largely controlled by the parent-rock compositions, because these elements only exist in specific minerals and are difficult to be lost during transportation (Pettijohn et al, 1972;Taylor and McLennan, 1985). In the Hexi Corridor, preliminary results have been achieved in the case studies of analyzing the elemental compositions of aeolian sediments using major-and trace-element geochemical methods (e.g., Ren et al, 2014;Pan et al, 2019;Zhang et al, 2020), which provide basic data for this study to comprehensively identify the material sources of different dunes in the study area.…”

Section: Data and Analytical Methodsmentioning

confidence: 99%

“…In modern times, however, the expansion of population and socio-economic development of the Hexi Corridor, as well as the human-caused competitive redistribution of water resources, have led to the onset and enhancement of desertification in the Hexi Corridor (Pu, 2005). The expansions of sandy dunes and dune fields in the corridor, and even the combination with surrounding sandy desert, have occurred in the past 2 ka (Zhu and Wang, 1992;Ren et al, 2014).…”

Section: Geographical Geological Geomorphological and Hydrologicmentioning

confidence: 99%

“…Regarding the source of aeolian sediments, the provenance of sandy dunes in the Hexi Corridor was firstly investigated as early as 1959-1964 by the China's Minqin Comprehensive Experimental Station of Desertification Control (MCESDC) (MDCES, 1975;Zhu et al, 1980;Chang, 2019), and continues to this day (Ferrat et al, 2011;Ren et al, 2014;Zhang and Dong, 2015;Zhang et al, 2016Zhang et al, , 2020Chang, 2019).…”

Section: Geochemical and Sources Of Dune Sediments In The Hexi Corridormentioning

confidence: 99%

“…Due to the application of geochemical methods in recent years, it is possible to identify sediment sources more precisely (Wang, 2011;Ren et al, 2014;Pan et al, 2019;Zhang et al, 2020). In this study, based on geochemical evidences, we take the Gobi areas in the Huahai-Jiayuguan-Jinta region of the west Hexi Corridor (area A in Fig.…”

Section: Geochemical and Sources Of Dune Sediments In The Hexi Corridormentioning

confidence: 99%

“…2) and the Minqin Basin in the east Hexi Corridor (area C in Fig. 2) as the case examples (Ren et al, 2014;Pan et al, 2019;Zhang et al, 2020) to explore the material sources of sandy dunes developed in these regions.…”

Section: Geochemical and Sources Of Dune Sediments In The Hexi Corridormentioning

confidence: 99%

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Formation and dynamics of sandy dunes in the inland areas of the Hexi Corridor

Zhu

2020

Preprint

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Abstract. Dynamic changes of aeolian landforms and desertification under global warming in a middle-latitude desert belt, the Hexi Corridor in China, considered to be one of the source and engine area of sandstorms in China and Northern Hemisphere (NH), is a typical problem of climate change and landscape response, which need a comprehensive understanding of the history and forcing mechanisms of recent landform and environmental changes in the region. Based on the existing high-resolution satellite image interpretations, field investigations and observations, comprehensive evidences from geomorphological, aeolian-physical, granulometrical and geochemical analysis, this study discussed the formation of dune landforms, the mechanism of desertification and their environmental implications in the Hexi Corridor. The analytical results show that 80 % of the sand particles flow within a height of 20–30 cm near the surface, and about half of the sand particles flow within a height of 0.3–0.5 cm near the surface in the Hexi Corridor. The average height of the typical crescent-shaped dunes is about 6.75 m, and the minimum and maximum values are between 2.6 and 11.2 m. On the inter-annual and multi-year time scales, only the crescent-shaped dunes and chains of barchan dunes are moving or wigwagging in the study area, while the parabolic and longitudinal dunes did not move. Under the influence of wind speed, strong wind days and other factors, the dunes at the edge of the Minqin Oasis move the fastest, with a moving speed of about 6.2 m/a. Affected by the main wind direction and other factors, the dunes at the edge of the Dunhuang Oasis move the slowest, with a moving speed of about 0.8 m/a. The main factors affecting the dynamic changes of sandy dunes in the Hexi Corridor are the annual precipitation, the annual average wind speed and the number of annual strong wind days, of which the annual precipitation contributes the largest, indicating that the climate factors have a most important impact on the dynamic change of sand dunes. The cumulative curve of particle size frequency of dune sediments in the Hexi Corridor basically presents a three-segment model, indicating a saltation mode dominated under the action of wind, but superimposed with a small amount of coarser and finer particles dominated by the creeping and suspension models, which is obviously different from that of the Gobi sediments with a dominant two-segment mode. The palaeo-geographical, sedimentological and geochemical evidences indicate that dune sediments in the Hexi Corridor are mainly derived from locally or in-situ raised sandy sediments, which are mainly come from alluvial plains and ancient fluvial sediments, as well as ancient lake plains and lacustrine deposits, aeolian deposits in the piedmont denudation zones of the north and south mountains and modern fluvial sediments in the corridor. In geochemical compositions of major and trace elements, the dunes in the Hexi Corridor have certain similarities and differences to other sandy dunes in the northwest and northern deserts of China or aeolian loess in the Loess Plateau. Sandy dunes in the Hexi Corridor are relatively rich in iron and Co. Considering the proportion of fine particles on the surface, the coverage rate of surface salt crust, and the potential migration of erodible sandy materials, it can be concluded that the Gobi area in the west Hexi Corridor is not the main source area of sandstorms in the middle and east of the corridor, but the north probably is. In the past half century, the warming and humidification of local climate is the main cause of the reduction of sandstorms in the study area, and the Hexi Corridor has a potential trend of anti-desertification, which is mainly controlled by climate change but not human activities. For the oasis areas of the corridor, however, the effective measures to restrict desertification depend on human activities. Restriction of the decline of groundwater is the key to preventing desertification in oases, rather than water transfer from outer river basins.

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Section: Data and Analytical Methodsmentioning

confidence: 99%

Section: Geographical Geological Geomorphological and Hydrologicmentioning

confidence: 99%

Section: Geochemical and Sources Of Dune Sediments In The Hexi Corridormentioning

confidence: 99%

Section: Geochemical and Sources Of Dune Sediments In The Hexi Corridormentioning

confidence: 99%

Section: Geochemical and Sources Of Dune Sediments In The Hexi Corridormentioning

confidence: 99%

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Formation and dynamics of sandy dunes in the inland areas of the Hexi Corridor

Zhu

2020

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Mechanisms of land degradation and their environmental implications in a middle‐latitude desert area of China

Zhu

2021

Land Degrad Dev

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The movement of aeolian materials and dynamics of dune landforms are results of the transportation and accumulation of sandy sediments under the influence of climate, in which the processes that gave birth to sand dune formations are complex as the arid area has experienced different periods of humidity and aridity. These dynamics are still not well understood at present, especially at the inter-decadal time scale.Based on a comprehensive analysis of geomorphological, sedimentological, geochemical, and ecohydrological data, this study discussed the dynamical changes of different dune landforms during the past half-century and their formation mechanism in the Hexi Corridor, northern China. The results show that on the inter-annual and inter-decadal scales, the crescent-shaped dunes move the fastest among different dune types. Dunes in Minqin move the fastest (at 6.2 ± 0.5 m yr À1 ) and dunes in Dunhuang move the slowest (at 0.8 ± 0.2 m yr À1 ). The dune sands are mainly medium sand (21.7%-57.4%) and fine sand (23.2%-53.0%) with an average grain size of 0.07 ± 0.01 mm $0.24 ± 0.06 mm, similar to the world's average particle size of sand dunes. Annual precipitation and spring precipitation, annual average wind speed, and number of annual strong wind days are the main factors affecting the dynamic changes of dunes in the Corridor, indicating a major influence of climatic factors. STC (sufficient transport capacity) is evidenced for both the western and eastern Hexi Corridor, however, SSS (sufficient sand supply) and SA (sand availability) are the favourable factor for dune formation in the east part but is the limiting factor for the west. In the past half-century, although the vulnerability of land degradation is a function of climate change, geomorphological processes, and anthropogenic pressure in the Hexi Corridor, water resource limitations have been more important.

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