Introduction

Deserts are formed through long-term development and evolution under the basic conditions of an arid climate and abundant sources of sand1. China’ s deserts are distributed in an arc-shaped pattern that extends across northern China1,2. These deserts vary in terms of climate3,4,5, source rocks6, topography, and other natural conditions1. The characteristics of climate and provenance have an important influence on the material composition of surface weathering crusts such as soil7. It is unclear whether climate and provenance affect the geochemical distribution characteristics of the desert sediments in northern China under such significant differences. The exploration of a geochemical index that can effectively reflect the impact of climate and provenance on desert sediments would provide an important research tool.

The mineralogical maturity is an important geochemical index based on the major element composition8,9,10,11,12,13,14. The mineralogical maturity is the degree to which the characteristics of clastic materials approach those of mature sandstone, and it can effectively reflect the composition of clastic sediments and measure the enrichment degree of stable minerals in sediments relative to unstable minerals15,16. Compared with other geochemical indicators, the mineralogical maturity can most directly and sensitively indicate the chemical weathering intensity, mechanical wear during transportation, and degree of re-transformation after deposition in the source area. Therefore, studying the mineralogical maturity of desert sediments can provide a corresponding theoretical basis for understanding the provenance of desert sediments, sediment transport processes, and evolution of wind-formed landscapes17,18,19. The mineralogical maturity is influenced by the following factors: (1) A higher quartz concentration in the sediment source area generally results in a higher mineralogical maturity of the derived sediments17; and (2) Under certain climatic conditions, weathering reduces the abundances of feldspar and lithic particles in sediments20, resulting in the relative enrichment of quartz13 and an increase in the mineralogical maturity17. Therefore, the mineralogical maturity can serve as an index for investigating the impact of climate and provenance on the geochemical distribution characteristics of the desert sediments in northern China.

Unfortunately, insufficient research has been conducted on the mineralogical maturity of the desert sediments in northern China. Most previous studies have focused on the mineralogical maturity of sediments within individual deserts19,21, and complete information about the mineralogical maturity of the deserts in northern China is lacking. In recent years, scholars have begun to systematically study the major element characteristics of desert sediments throughout northern China22,23; however, little research has focused on the mineralogical maturity of these sediments. In addition, although abundant samples have been collected in previous studies, the spatial distribution of these samples is uneven, and the sample distribution in the hinterlands of these deserts is insufficient, which affects the representativeness of these desert samples.

Besides, the particle size has an influence on the results of sediment composition measurements24. The particle size distribution of bulk desert sediment samples is geographically variable, that is, the sediments in the western deserts are finer-grained than the sediments in the eastern sandy lands25. Therefore, it is necessary to select and study a specific particle size to eliminate the particle size effect. Most previous studies either selected whole samples from multiple deserts nationwide23,26 for determination, or they selected one or more non-uniform particle-level in a desert16,19,27,28,29,30 for analysis. As a result, it is difficult to integrate the element data for these samples with different grain sizes, leading to difficulties in systematically comparing the mineralogical maturities of the desert sediments in northern China.

In addition, existing studies17,19,21 tend to emphasize the influence of provenance on the mineralogical maturity of sediments. Other influencing factors, such as different climate types4 and particle size distributions25, have been insufficiently studied.

In this study, we collected 325 sand samples from the crests of desert dunes in northern China, analyzed the major element abundances of the 125–250 μm sand fraction, and determined the mineralogical maturity of the sediments using the Log (SiO2/Al2O3) vs. Log (Na2O/K2O) diagram proposed by Pettijohn et al15. We then utilized data from this study and previous studies to analyze the potential influences of physical geographic factors, such as provenance and climate, on the regional distribution of the mineralogical maturity of the desert sediments in northern China. Furthermore, we demonstrated the possible influence of climate, in addition to physical sources, on the mineralogical maturity of global deserts, thus providing a basis for understanding the formation of mid-latitude deserts and their surface processes, as well as for ecological and environmental management in desert areas.

Regional setting and methods

Regional setting

The deserts in northern China are located in the mid-latitude temperate arid and semiarid climate zones (35–50°N, 75–125°E)22 and cover an area of approximately 80.89 × 104 km2 (Fig. 1)1,2. They are widely distributed in Xinjiang, Inner Mongolia, Qinghai, and Gansu provinces and exhibit a sizable contiguous distribution area31. In terms of the structural geologic setting, the deserts in northern China are primarily located on the North China Block and Tarim Block between the Tianshan-Xingmeng and Qinqi orogens and are surrounded by mountain systems formed in different time periods32,33.

Fig. 1
figure 1

Map showing the geographical location of the study area and the distribution of the sampling sites within the study area. (Western Deserts: 1. Taklamakan Desert, 2. Gurbantunggut Desert, 3. Qaidam Desert, 4. Kumtag Desert; Central Deserts: 5. Badain Jaran Desert, 6. Tengger Desert, 7. Ulan Buh Desert, 8. Kubuqi Desert, 9. Mu Us Sandy Land; Northeastern Sandy Lands: 10. Hunshandake Sandy Land, 11. Horqin Sandy Land, 12. Hulunbeir Sandy Land.) (The Fig. 1 was produced using ArcGIS Desktop 10.6 (Environmental Systems Research Institute, Redlands, CA, USA). DEM data downloaded from Geospatial Data Cloud (https://www.gscloud.cn/).)

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The Taklimakan Desert is located in the Tarim landmass area at an elevation of 3000 m above sea level and is surrounded by the Kunlun Mountains, Pamir Plateau, and Tianshan Mountains34. The Gurbantunggut Desert and the three sandy lands that comprise the Northeastern Sandy Lands are located in and around the Central Asian orogenic belt35. The Qaidam Desert is located on the Qaidam Block36 and is surrounded by the Kunlun, Qilian, and Altun Mountains37. The Badain Jaran Desert, Tengger Desert, and Ulan Buh Desert are mainly located on the Alexa Block38. The Mu Us Sandy Land and the Kubuqi Desert are located on the Ordos Massif, which is one of the most stable continental crustal areas in the North China Block16.

These deserts primarily developed on high-altitude plateaus and in inland intermountain basins. Due to the atmospheric circulation patterns, the degree of dryness in these deserts increases from east to west1. The 10-year average precipitation during 2010–2020 exhibited a decreasing trend overall, and the 10-year average temperature exhibited an increasing trend overall (Fig. 2).

Fig. 2
figure 2

Spatial distributions of the (a). annual mean precipitation and (b). annual mean temperature in China during 2011–2020. (Western Deserts: 1. Taklamakan Desert, 2. Gurbantunggut Desert, 3. Qaidam Desert, 4. Kumtag Desert; Central Deserts: 5. Badain Jaran Desert, 6. Tengger Desert, 7. Ulan Buh Desert, 8. Kubuqi Desert, 9. Mu Us Sandy Land; Northeastern Sandy Lands: 10. Hunshandake Sandy Land, 11. Horqin Sandy Land, 12. Hulunbeir Sandy Land.) (The Fig. 2 was produced using ArcGIS Desktop 10.6 (Environmental Systems Research Institute, Redlands, CA, USA). The data were derived from the Climate Research Unit Time Series (CRU TS) version 4.06 dataset published by the National Centre for Atmospheric Sciences (https://crudata.uea.ac.uk/cru/data/hrg/).)

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The Gurbantunggut Desert, Mu Us Sandy Land, and Northeastern Sandy Lands (Hunshandake, Horqin, and Hulunbeir) are composed of fixed and semi-fixed dunes that reflect the abundant annual precipitation and vegetation, whereas the other deserts are mainly composed of wandering dunes1. The desert dunes in northern China have diverse morphologies. In addition to the common semilunar dunes and dune chains that commonly form in deserts, parabolic dunes, lattice dunes, sand dunes, honeycomb dunes, pyramid dunes, scaled dune, dome-shaped dunes, and other complex dunes are widely distributed in the 11 deserts investigated in this study1 (Table 1).

Table 1 General description of deserts in northern China.
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Materials and methods

Sampling and data

We conducted extensive field investigations in 11 deserts in northern China (Fig. 3). A total of 325 sand samples were collected, and these samples were primarily selected from the representative dunes (Fig. 1). Approximately 1000 g of sample were collected from the top 10 cm of the surface. Sample collection was conducted while ensuring that the samples were as evenly distributed within the deserts as possible. The latitude and longitude information of the sampling points is provided in supplementary material 1. The distribution of the sampling sites within the 11 major deserts in northern China is presented in supplementary material 2.

Fig. 3
figure 3

Photographs of the fieldwork (Note: Photos taken by Feng Zhang).

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To investigate the effect of provenance on the mineralogical maturity of the desert sediments, data for a total of 129 fluvial sand samples from eight deserts and 134 rock samples from the mountain ranges surrounding the northern China deserts were compiled from the literature (Table 2 and references therein).

Table 2 Summary of desert sediment and source rock major element data from the literature.
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In order to study whether the spatial variations in the mineralogical maturity of the desert sediments are affected by climate on a global scale, the major element abundances of 179 sediment samples from 11 deserts in other regions of the world were compiled from recent publications (Table 2 and references therein).

Laboratory analyses

The grain sizes of northern China desert sands vary but are predominantly represented by the fine sand fraction53,54,55,56,57,58,59,60,61,62,63,64,65. In this study, we evaluated only the 125–250 μm sand fraction to ensure the representativeness of samples from each desert. To separate the 125–250 μm grain size fractions, the samples were sieved at the Soil Laboratory of the College of Resources and Environmental Sciences, Xinjiang University. The samples were then pulverized to < 75 μm (Tyler standard 200 mesh) using a corundum mortar and dried in an oven at 105 °C for 5 h.

We analyzed major element (SiO2, Al2O3, Na2O, and K2O) abundances at the Key Laboratory of Loess and Quaternary Geology, Chinese Academy of Sciences according to the experimental steps proposed by Tursun et al21. First, 0.6 g of powdered sample was mixed with 6 g of dilithium tetraborate (Li2B4O7) flux. Two drops of lithium bromide (LiBr) were added as a releasing agent. The mixture was melted at a temperature of 1100 °C for approximately 19 min, and the melted liquid was poured into a platinum crucible. After the sample was cooled to room temperature, it was analyzed via X-ray fluorescence spectrometry (Axios advanced PW4400, Netherlands). A total of 20 analyses were repeated, and national standard substances (GSW) were tested simultaneously with the samples for calibration. The relative error of the data was < 5%.

Data analysis

The mineralogical maturity was determined using the Log (SiO2/Al2O3) vs. Log (Na2O/K2O) diagram proposed by Pettijohn et al15. Sediments with a higher degree of mineralogical maturity have higher Log (SiO2/Al2O3) and lower Log (Na2O/K2O) values14.

We used ArcGIS 10.6 to plot the 10-year (2011–2020) average spatial distributions of the temperature and precipitation in China and around the world. Based on the latitude and longitude of the sand samples, the 10-year average temperature values and precipitation values of each sand sample were extracted. The data were derived from the Climate Research Unit Time Series (CRU TS) version 4.06 dataset published by the National Centre for Atmospheric Sciences, which provides monthly data covering the land surface from 1901 to 2020 with a 0.5° resolution. The applicability of this dataset has been validated on the global scale66.

Results

The characteristics of the mineralogical maturity of the sediments are described below.

  1. (1)

    The mean Log (SiO2/Al2O3) values of the sands from the Western Deserts, Central Deserts, and Northeastern Sandy Lands are 0.84, 0.92, and 1.03, respectively. The values gradually increase from the Western Deserts to the Central Deserts to the Northeastern Sandy Lands (Table 3).

  2. (2)

    The mean Log (Na2O/K2O) values of the sands from the Western Deserts, Central Deserts, and Northeastern Sandy Lands are 0.03, 0.08, and − 0.21, respectively (Table 3).

  3. (3)

    The distributions of the Log (SiO2/Al2O3) values (0.70–1.06) and Log (Na2O/K2O) values (− 0.43–0.26) of the Gurbantunggut Desert samples are discrete compared to those of the sediments from the other deserts (Table 3).

Table 3 Major element abundances (in wt/%) of the northern China desert sands (125–250 μm).
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The mineralogical maturity of the aeolian sands varies by region. Overall, the mineralogical maturity increases from the Western Deserts to the Central Deserts to the Northeastern Sandy Lands (Fig. 4). The mineralogical maturities of the sands from the Western Deserts, including the Taklamakan, Qaidam, and Gurbantunggut deserts, are generally low. The spatial distribution of the mineralogical maturity is particularly distinct in the Gurbantunggut Desert. The mineralogical maturities of the sediments in the hinterland of the Gurbantunggut Desert are similar to those of the Northeastern Sandy Lands (Fig. 4).

Fig. 4
figure 4

Plot of mineralogical maturity of sands from the deserts in northern China.

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The sands in the Central Deserts, such as the Badain Jaran, Tengger, Ulan Buh, Kubuqi, and Mu Us, have the second highest mineralogical maturities (Fig. 4). The spatial distribution of the mineralogical maturity zones in the Mu Us Sandy Land is distinct compared to the other Central Deserts. The mineralogical maturities of the sediments from the eastern part of the Mu Us Sandy Land are similar to those of the Western Deserts (Fig. 4). In addition, the distributions of the Log (Na2O/K2O) values of the sands from the Central Deserts and Western Deserts are similar, but the Log (SiO2/Al2O3) values of the sands from the Central Deserts (0.69–1.11) are substantially higher overall than those of the samples from the Western Deserts (0.68–1.06) (Fig. 4, Table 3).

The samples from the Northeastern Sandy Lands, including the Hunshandake, Hulunbeir, and Horqin sandy lands, have higher mineralogical maturities than those of the sands in the other two regions (Fig. 4). The Log (SiO2/Al2O3) range of the sands in the Northeastern Sandy Lands is roughly similar to that of the sands in the Central Deserts, but the Log (Na2O/K2O) values (− 0.32 to − 0.06) of the sands in the Northeastern Sandy Lands are generally lower than those of the sands in the Central Deserts (− 0.09 to 0.22) (Fig. 4, Table 3).

Discussion

Roles of different influencing factors in the regional distribution of the mineralogical maturity of the desert sediments in northern China

Provenance

A higher quartz concentration in the sediment source area generally results in a higher mineralogical maturity of the derived sediments17. The desert sediments in China primarily formed through weathering and erosion of the surrounding mountain ranges and basement rocks16,19,21,22,29,30,40,62,67,68,69,70,71,72. In this study, we found that the mineralogical maturities of the desert sediments in northern China obviously overlap with the mineralogical maturities of the source rocks around the deserts reported in previous studies (Fig. 5, Table 2 and references therein), and thus, they also demonstrate the characteristics of the source areas near the deserts in northern China. The mineralogy and major element compositions of the surrounding mountain ranges and basement rocks vary6,46,48,49,50,69,73,74,75,76,77,78, which may be the cause of the east–west variability of the major element compositions (Table 3) of the desert sediments in northern China.

Fig. 5
figure 5

Mineralogical maturity of sediments from the (a). Western Deserts, (b). Central Deserts, and (c). Northeastern Sandy Lands in northern China.

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The reason for the high mineralogical maturities of the desert sediments in the Northeastern Sandy Lands may be related to the high SiO2 and K2O contents of the source rocks. The mean SiO2 concentration of the rocks in the Greater Khingan Mountains, which surround the Northeastern Sandy Lands, is higher than that of the rocks in the Altay and Kunlun Mountains, which surround the Western Deserts, and the rocks in the Langshan and Qilian Mountains, which surround the Central Deserts (Table 2 and references therein, Table 4). Thus, the relatively high SiO2 concentrations of the sediments in the Northeastern Sandy Lands (Table 3) may be inherited from their source rocks (Table 4). The higher quartz content of the source rocks of the Northeastern Sandy Lands may explain why the mineralogical maturity of the sands in the Northeastern Sandy Lands is higher than those of the sediments in the other two regions (Fig. 4).

Table 4 Average major element abundances (in wt%) of the rocks in mountain ranges in northern China.
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Furthermore, the K2O concentrations of the rocks in the Greater Khingan Range, which is adjacent to the Northeastern Sandy Lands, are greater than those of the source rocks in the mountains around the Western Deserts and Central Deserts (Table 4). These source rocks include potassium-rich granite, basalt, and monzogranite79.The inheritance of the high K2O concentrations of the rocks in the Greater Khingan Range may explain why the sands in the Northeastern Sandy Lands have lower Log (Na2O/K2O) values (Table 3) and higher mineralogical maturities (Fig. 4) than those of the sediments in the other two regions.

Rivers continuously transport debris from the surrounding mountains1,16,21,22,80, which in turn provides material sources for dune sands. In addition, the mineralogical maturity range of the fluvial sands significantly overlaps that of the dune sands (Fig. 5), indicating that these sediments have a similar geochemical signature. It can be proved that the fluvial sands are an important source of the dune sands in the deserts in northern China. Thus, the consistent spatial variations in the mineralogical maturities of the fluvial sands and dune sands (Fig. 6) corroborate the influence of the provenance on the mineralogical maturity of the dune sands in the deserts in northern China.

Fig. 6
figure 6

Mineralogical maturity of (a). dune sands and (b). fluvial sands from different regions in northern China.

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Climate

Chemical weathering is a vital process that influences the evolution of the Earth’s surface78. It can reduce the abundances of feldspar and lithic particles in sediments20, resulting in the relative enrichment of quartz13 and an increase in the mineralogical maturity17. The weathering intensity of the Earth’s surface is largely dependent on the climatic conditions78. Therefore, the type of climate may affect the distribution of the mineralogical maturity of the desert sediments in northern China determined based on the provenance.

Abundant precipitation favors weathering81, which leads to a higher mineralogical maturity82. In this study, it was found that the mineralogical maturity of the aeolian sands in northern China exhibits a strong positive correlation with the 10-year mean precipitation (Fig. 7a). This indicates that the mineralogical maturity of the aeolian sands increases with increasing precipitation in northern China. The precipitation increases from the Western Deserts (1.42–25.23 mm) to the Central Deserts (3–40.99 mm) to the Northeastern Sandy Lands (20.56–47.08 mm) in northern China (Fig. 2a). The spatial variations in the mineralogical maturity of the desert sediments (Fig. 4) are consistent with this precipitation trend (Fig. 2a). Therefore, it may indicate that the differences in the precipitation (Fig. 2a) across northern China lead to varying chemical weathering intensities and differences in the mineralogical maturity (Fig. 4).

Fig. 7
figure 7

Relationships between the mineralogical maturity of samples and (a). annual mean precipitation and (b). annual mean temperature in China during 2011–2020. (The sediments with a higher degree of mineralogical maturity have higher Log (SiO2/Al2O3) and lower Log (Na2O/K2O) values, so the Log (SiO2/Al2O3) − Log (Na2O/K2O) values represent the mineralogical maturity, and the increase in this value indicates an increase in the mineralogical maturity of the sediment to some extent.)

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Temperature is the main factor that controls the degree of weathering of silicate minerals. At lower temperatures, the rate of feldspar weathering decreases, leading to a lower sediment maturity20. As the average temperature of the deserts in northern China decreases from the Western Deserts (− 4.68–14.04 °C) to the Central Deserts (6.34–10.18 °C) to the Northeastern Sandy Lands (− 0.77–8.37 °C) (Fig. 2b), the mineralogical maturity should decrease from west to east in northern China. However, the mineralogical maturity of the aeolian sands in northern China exhibits a good negative correlation with the 10-year mean temperature (Fig. 7b). The mineralogical maturity of the Northeastern Sandy Lands, which have lower temperatures, measured in this study is the highest (Fig. 4). This trend may be caused by the fact that the temperature in northern China is generally low (-4.68–14.04 °C) (Fig. 2b), and the influence of temperature on mineralogical maturity is limited. Temperature does not alter the distribution pattern of mineralogical maturity of desert sediments in northern China, which are controlled by the provenance and precipitation.

Considering that temperature or precipitation alone cannot fully reveal the impact of the type of climate on weathering. In previous comprehensive studies of the effects of precipitation and temperature on deserts78,83, the deserts in northern China were classified as hyperarid deserts, arid deserts, and semiarid deserts based on the aridity index (AI) (i.e., the ratio of the annual precipitation to the annual potential evapotranspiration).

The Taklamakan, Gurbantunggut, and Qaidam deserts in western China are located deep in the interior of the Eurasian continent. In this region, the mountains block the flow of humid air from the Pacific Ocean, resulting in an arid continental climate25. This region is dominated by hyperarid and arid deserts. Except for the Badain Jaran Desert, which is a hyperarid desert, the other Central Deserts are arid or semiarid. The Northeastern Sandy Lands are influenced by the East Asian summer winds and have a semihumid climate in some areas58, and the deserts in this region are all semiarid. Therefore, from west to east, the deserts in northern China transition from hyperarid to arid and semiarid. This trend is consistent with the spatial distribution pattern of the mineralogical maturity.

In summary, the spatial variation trend of the mineralogical maturity of the desert sediments in northern China is roughly consistent with the overall distribution pattern of climate types and the precipitation trend alone in China.

Integrity of northern China and the impact of climate on the mineralogical maturity of desert sediments on the global scale

Strong chemical weathering under the influence of high temperatures leads to an increase in the mineralogical maturity of desert sediments20. In Section “Climate”, we revealed that the spatial variations in the temperature are not consistent with the spatial distribution of the mineralogical maturity of the desert sediments in northern China (Fig. 7b). In particular, the Northeastern Sandy Lands have lower temperatures (Fig. 2b) and a higher mineralogical maturity (Fig. 4). This trend may be explained by the relatively low temperatures in northern China (-4.68–14.04 °C) and the small temperature difference in the east–west direction. A larger spatial scale may be needed to discuss the impacts of weathering processes, which are affected by climatic conditions, on the mineralogical maturity of desert sediments.

There are obvious regional differences in the mineralogical maturity of the sediments in the deserts in northern China (Fig. 4), but the overall range is less than that of sands in other deserts around the world (Fig. 8). On a large scale, the mineralogical maturities of desert sediments in adjacent geographic locations are roughly identical. For example, the Algodones Dunes, Parker dunes, Nebraska Sand Hills, Casper dune field, and other deserts in the United States have similar mineralogical maturities.

Fig. 8
figure 8

Plot of mineralogical maturity in sediments from dune fields around the world.

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The average annual temperatures in the Great Sandy Desert (17–23°S, 120–129°E) and the Zallaf Sand Sea (27–28°S, 14–15°E) are generally higher than those of other deserts (Fig. 9a), and their mineralogical maturities are also higher overall (Fig. 8). The deserts in northern China (35–50°N, 75–125°E) and the Casper dune field (42.8–43°N, 105–106°W) and Nebraska Sand Hills (41–43°N, 98–103°W) in the United States have lower average annual temperatures than other deserts due to their higher latitudes (Fig. 9a), and their mineralogical maturities are lower overall (Fig. 8).

Fig. 9
figure 9

Spatial distributions of the (a). annual mean temperature and (b). annual mean precipitation worldwide during 2011–2020. (The Fig. 9 was produced using ArcGIS Desktop 10.6 (Environmental Systems Research Institute, Redlands, CA, USA). The data were derived from the Climate Research Unit Time Series (CRU TS) version 4.06 dataset published by the National Centre for Atmospheric Sciences(https://crudata.uea.ac.uk/cru/data/hrg/).)

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Moreover, our results indicate that there is a significant positive correlation between the mineralogical maturity and the 10-year mean temperature for global desert sediments (Fig. 10a). The weathering of feldspar-like minerals intensifies with increasing temperature20, leading to a significant increase in the mineralogical maturity of global desert sediments (Fig. 10a). On the global scale, we found that the temperature distribution is significantly correlated with the spatial distribution of the mineralogical maturity of global desert sediments.

Fig. 10
figure 10

Relationships between the mineralogical maturity of the samples and (a). annual mean precipitation and (b). annual mean temperature worldwide during 2011–2020.

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Due to the dry air and little or no annual rainfall in desert areas, the 10-year average precipitation values of in deserts around the world are generally less than 50 mm (Fig. 9b). In different deserts around the world, the amount of precipitation does not vary appreciable at the global scale. In addition, although there is a positive correlation between the mineralogical maturity of global desert sediments and the 10-year mean precipitation, the correlation is weak (Fig. 10b).

To some extent, the mineralogical maturity can reflect the degree of chemical weathering of desert sediments and the possible climatic environment of the desert17,18,19. The climate formation mechanism of deserts differs in different regions of the world. For example, the North African deserts (Grand Erg Oriental and Zallaf Sand Sea), South African desert (Namib Sand Sea), South-West Asian deserts (Negev dune field and Sinai dune field), and Australian desert (Great Sandy Desert) are mainly affected by the sinking airflow of the Hadley circulation. Deserts are concentrated in the subtropical region. The high pressure in this region inhibits atmospheric convective precipitation and increases atmospheric stability, thus forming a continuous subtropical arid desert area84. The deserts in North America (Algodones Dunes, Parker dunes, Nebraska Sand Hills, and Casper dune field) were mainly formed due to the suppression of local evaporation and convection caused by cold ocean currents and offshore trade winds. Moreover, the amount of precipitation is low, leading to the formation of deserts84. The East Asian deserts (the deserts in Northern China) are mainly located far from the ocean, and it is difficult for water vapor to reach this region. The lack of precipitation and the rain shadow effect of the plateau mountains are also important reasons for the formation of deserts in this region85. Therefore, the different climate types of desert areas in different regions of the world inevitably result in different degrees of chemical weathering and thus different mineralogical maturities (Fig. 8). The weathering status of the deserts in northern China, which is reflected by the mineralogical maturity, is consistent with the temperate desert climate characteristics of the deserts in northern China in terms of the global climate zones.

Recognition of desert evolution stage in northern China based on mineralogical maturity

Muh17 showed that many deserts around the world, such as the Great Sandy Desert in Australia, the Algodones Dunes and the Parker dunes in the USA, and the Zallaf Sand Sea in Libya, inherited their high mineralogical maturities from their quartz-rich source rocks, and their provenances are the main reason for the high mineralogical maturities of their sediments. In general, in the early stage of sand entering the desert, the characteristics of the original rocks in the source area will be maintained to a certain extent17. In this stage, the mineralogical maturity of the sediment is greatly affected by the type of source rock. With the passage of time, the chemical weathering, which is affected by the climatic conditions, or the mechanical loss of feldspar and rock fragments begins to play a significant role. After a long and repeated cycle of weathering, erosion, and transportation86, other factors such as climate will affect or even dominate the mineralogical maturity to a certain extent, thus changing the distribution pattern of the desert sediments formed by the provenance17.

According to our results, the influence of the provenance on the spatial distribution of the mineralogical maturity of the desert sediments in northern China is significant (Section "Provenance"). Therefore, sediments may not have entered the deserts in northern China for a long time.

Furthermore, the aeolian sediments in northern China have a lower mineralogical maturity compared to other global sediments, especially deserts in the tropics. This phenomenon is consistent with the low degree of weathering in the temperate deserts in northern China. Without excluding the influence of the mineral composition on the mineralogical maturity of sediments on the global scale, it can be tentatively concluded that the weathering degree of the desert sands in northern China indicates that these deserts are in the early stage of desert evolution.

This study takes mineralogical maturity as a theoretical basis for understanding the source of desert sediments, the process of sedimentary migration, and the evolution of aeolian landscapes17,18,19 to improve the understanding of desert surface processes in northern China. However, despite its importance, mineralogical maturity provides only a geochemical index of major elements in desert sediments. To comprehensively and reliably elucidate the evolution process of desert sediments in northern China, mineralogical maturity should be complemented and verified based on the examination of trace elements, isotopes, heavy minerals, and other methods in follow-up research.

Conclusions

In this study, we analyzed the major element abundances of 325 sediment samples from 11 deserts in northern China and evaluated their mineralogical maturities using the method proposed by Pettijohn et al.

  1. (1)

    Overall, the mineralogical maturity of the desert sands in northern China exhibits regional variations and increases from west to east, that is, from the Western Deserts to the Central Deserts to the Northeastern Sandy Lands.

  2. (2)

    The mineralogical maturities of the fluvial sands and dune sands in the deserts in northern China are similar, and the fluvial sands may be an important source of the dune sands.

  3. (3)

    The SiO2 and K2O concentrations of the basement rocks adjacent to the Northeastern Sandy Lands, Western Deserts, and Central Deserts are consistent with the spatial distribution of the composition of the desert sediments, demonstrating that the provenance affects the mineralogical maturity.

  4. (4)

    The mineralogical maturity of the desert sediments in northern China increases from west to east, which is consistent with the of warm and humid climate in the eastern part of northern China and the dry and cold climate in the western part of northern China.

  5. (5)

    On the global scale, the mineralogical maturity of the desert sediments in northern China is lower than those of other deserts sediments around the world, especially deserts in the tropics. This phenomenon is consistent with the low degree of weathering in the temperate deserts in northern China.

  6. (6)

    Without excluding the influence of global provenance on the mineralogical maturity, it can be tentatively concluded that based on the characteristics of their sediments, the deserts in northern China are in the early stage of desert evolution.

  7. (7)

    The results of this study provide a basis for understanding the formation of mid-latitude deserts and their surface processes, as well as for ecological and environmental management in desert areas.