Search Results (162)

The Kekeya oilfield is located at the southwestern edge of the Tarim Basin, in the southern margin of the Yecheng depression, at the western end of the second structural belt of the northern foothills of the Kunlun Mountains. It is one of the important oil and gas fields in western China, with significant oil and gas resource potential in the X4-X5 section of the Xihepu Formation. This study focuses on the edge of the alluvial fan depositional system, employing various techniques, including core data and well logging data, to precisely characterize the sand body architecture and comprehensively analyze the reservoir architecture in the study area. First, the regional geological background of the area is analyzed, clarifying the sedimentary environment and evolutionary process of the Xihepu Formation. Based on the sedimentary environment and microfacies classification, the sedimentary features of the region are revealed. On this basis, using reservoir architecture element analysis, the interfaces of the reservoir architecture are finely subdivided. The spatial distribution characteristics of the planar architecture are discussed, and the spatial distribution and internal architecture of individual sand body units are analyzed. The study focuses on the spatial combination of microfacies units along the profile and their internal distribution patterns. Additionally, a quantitative analysis of the sizes of various types of sand bodies is conducted, constructing the sedimentary model for the region and revealing the control mechanisms of different sedimentary architectures on reservoir properties and oil and gas accumulation patterns. This study pioneers a quantitative model for alluvial fan fringe in gentle-slope basins, featuring the following: (1) lobe width-thickness ratios (avg. 128), (2) four base-level-sensitive boundary markers, and (3) a retrogradational stacking mechanism. The findings directly inform reservoir development in analogous arid-climate systems. This research not only provides a scientific basis for the exploration and development of the Kekeya oilfield but also serves as an important reference for reservoir architecture studies in similar geological contexts. Full article

Under accelerating global warming, the northern slope of the Middle Kunlun Mountains in Xinjiang, China, has seen a marked rise in extreme rainfall, posing increasing challenges for flood risk management and water resources. To improve our predictive capabilities and deepen our understanding of the driving mechanisms, we combine the European Centre for Medium-Range Weather Forecasts Reanalysis-5 (ERA5) reanalysis, regional observations, and high-resolution Weather Research and Forecasting model (WRF) simulations to dissect the 14–17 June 2021, extreme rainfall event. A deep Siberia–Central Asia trough and nascent Central Asian vortex established a coupled upper- and low-level jet configuration that amplified large-scale ascent. Embedded shortwaves funnelled abundant moisture into the orographic basin, where strong low-level moisture convergence and vigorous warm-sector updrafts triggered and sustained deep convection. WRF reasonably replicated observed wind shear and radar echoes, revealing the descent of a mid-level jet into an ultra-low-level jet that provided a mesoscale engine for storm intensification. Momentum–budget diagnostics underscore the role of meridional momentum transport along sloping terrain in reinforcing low-level convergence and shear. Together, these synoptic-to-mesoscale interactions and moisture dynamics led to this landmark extreme-precipitation event. Full article

Arid grasslands exhibit high proportions of belowground biomass (BGB), yet the climatic influence on BGB carbon density remains poorly understood. Accurately estimating BGB carbon density in arid grassland vegetation presents a significant challenge. Using extensive field sampling, multi-source remote sensing data, and machine learning methods, the spatial distribution of BGB carbon density across Xinjiang grasslands was estimated, and its environmental drivers across different geomorphological regions were revealed. The results show that BGB carbon density accounts for 93.8–97.2% of total carbon density in Xinjiang grassland, with notably high proportions exceeding 97% in the Junggar Basin, Kunlun Mountains, and Altun Mountains regions. From 2000 to 2023, BGB carbon density increased significantly (p < 0.01) from 1175.18 gC·m⁻² to 1379.09 gC·m⁻², with significant increases observed in the Junggar Basin, Tarim Basin, Kunlun Mountains, and Altun Mountains. In addition, environmental factor analysis revealed distinct soil moisture threshold effects governing BGB carbon density-precipitation relationships: carbon density increases linearly with precipitation when soil moisture remains below 0.2 m³·m⁻³, shows a parabolic relationship between 0.2 and 0.4 m³·m⁻³, and decreases with increasing precipitation when soil moisture exceeds 0.4 m³·m⁻³. Soil moisture and precipitation emerge as dominant factors influencing BGB carbon density changes, with regional variations in their relationships. These findings provide critical insights into carbon sequestration dynamics in arid grassland ecosystems and their response mechanisms under climate change. Full article

The Qieliekeqi siderite deposit, located in the Tashkurgan block of western Kunlun, is a carbonate-hosted iron deposit with hydrothermal sedimentary features. This study integrates whole-rock geochemistry, stable isotopes, and zircon U–Pb–Hf data to investigate its metallogenic evolution. Coarse-grained siderite samples, formed in deeper water, exhibit average Al₂O₃/TiO₂ ratios of 29.14, δEu of 2.69, and δCe of 0.83, indicating hydrothermal fluid dominance with limited seawater mixing. Banded samples from shallower settings show an average Al₂O₃/TiO₂ of 17.07, δEu of 3.18, and δCe of 0.94, suggesting stronger seawater interaction under oxidizing conditions. Both types are enriched in Mn, Co, and Ba, with low Ti and Al contents. Stable isotope results (δ¹³C_PDB = −6.0‰ to −4.6‰; δ¹⁸O_SMOW = 16.0‰ to 16.9‰) point to seawater-dominated fluids with minor magmatic and meteoric contributions, formed under open-system conditions at avg. temperatures of 53 to 58 °C. Zircon U–Pb dating yields an age of 211.01 ± 0.82 Ma, with an average εHf(t) of −3.94, indicating derivation from the partially melted ancient crust. These results support a two-stage model involving Late Cambrian hydrothermal sedimentation and Late Triassic magmatic overprinting. Full article

Late Paleozoic to Early Mesozoic granitoids in the East Kunlun Orogenic Belt (EKOB) provide critical insights into the complex and debated relationship between Paleo–Tethyan magmatism and tectonics. This study presents integrated bulk-rock geochemical and zircon isotopic data for the Xingshugou monzogranite (MG) to address these controversies. LA-ICP-MS zircon U-Pb dating constrains the emplacement age of the MG to 247.1 ± 1.5 Ma. The MG exhibits a peraluminous and low Na₂O A₂-type granite affinity, characterized by high K₂O (4.69–6.80 wt.%) and Zr + Nb + Ce + Y (>350 ppm) concentrations, coupled with high Y/Nb (>1.2) and A/CNK ratios (1.54–2.46). It also displays low FeO^T, MnO, TiO₂, P₂O₅, and Mg^# values (26–49), alongside pronounced negative Eu anomalies (Eu/Eu* = 0.37–0.49) and moderately fractionated rare earth element (REE) patterns ((La/Yb)_N = 3.30–5.11). The MG exhibits enrichment in light rare earth elements (LREEs) and large ion lithophile elements (LILEs; such as Sr and Ba), and depletion in high field strength elements (HFSEs; such as Nb, Ta, and Ti), collectively indicating an arc magmatic affinity. Zircon saturation temperatures (T_Zr = 868–934 °C) and geochemical discriminators suggest that the MG was generated under high-temperature, low-pressure, relatively dry conditions. Combined with positive zircon ε_Hf(t) (1.8 to 4.7) values, it is suggested that the MG was derived from partial melting of juvenile crust. Synthesizing regional data, this study suggests that the Xingshugou MG was formed in an extensional tectonic setting triggered by slab rollback of the Paleo-Tethys Oceanic slab. Full article

Tibetan hulless barley (qingke) grains are becoming more popular because of their high nutritional benefits. Comparative metabolomics and proteomics analyses of qingke grains (at 16, 20, 36, and 42 days after flowering) were conducted to explore the metabolic dynamics during grain filling and compare the differences in quality among three different varieties, Dulihuang, Kunlun 14, and Heilaoya. A total of 728 metabolites and 4864 proteins were identified. We first found that both the metabolite and protein profiles were more closely associated with the grain developmental stage in each cultivar than across different stages in a single cultivar. Next, we focused on the energy metabolism and biosynthesis pathways of key quality components, such as flavonoids, starch, and β-glucans in qingke grains. Quantitative analysis revealed significant variation in the abundance of cellulose synthase-like enzyme (CslF) among the three cultivars. Notably, Heilaoya displayed substantially lower CslF6 levels at 36 and 42 DAF than Kunlun 14 and Dulihuang did. These observed differences in CslF6 abundance may represent a key regulatory mechanism underlying the distinct β-glucan biosynthesis patterns among the three cultivars. Collectively, our results enhance the understanding of metabolic networks involved in qingke grain development and serve as a foundation for advancing breeding studies. Full article

Remote sensing technology has significant technical advantages over traditional geological methods in geological mapping and mineral resource exploration, especially in high-altitude and steep topography areas. Geochemical sampling and geological mapping methods in these areas are difficult to use directly in mountainous regions such as West Kunlun. Therefore, in the face of Li-Be-Nb-Ta mineralization of the Dahongliutan rare-metal pegmatite deposit in West Kunlun, remote sensing has become an effective means to identify areas of interest for exploration in the early stage of the exploration campaigns. Several methods have been developed to detect pegmatites. Still, in this study, this methodology is based on spectral analysis to select bands of the ASTER and Landsat-8 OLI satellites, and methods, such as principal component analysis (PCA) and mixture tuned matched filtering (MTMF), to delineate the prospective areas of pegmatite. The results proved that PCA could map the hydrothermal alteration and structure information for pegmatites. To define new locations of interest for exploration, we introduced the spectra of spodumene-bearing pegmatites and tourmaline-bearing pegmatites as endmembers for the MTMF approach. The results indicate that the location of pegmatite areas on the ASTER and Landsat-8 OLI images overlaps with the ore deposits, and the location of potential ore-bearing pegmatites is delineated using remote sensing and geological sampling. Although this does not guarantee that all prospective areas have the mining value of ore-bearing pegmatites, it can provide basic data and technical references for early exploration of Li. Full article

This study comprehensively assessed the effects of ten highland barley varieties on the quality and digestibility of noodles. The characteristics of highland barley flour, including proximate composition, pasting properties, and dough mixing behavior, were analyzed. The quality of the resulting noodles was evaluated through cooking and textural property analysis. The digestion characteristics of the noodles were determined to evaluate the starch hydrolysis rate and glycemic index (GI). Additionally, a correlation analysis was conducted among the proximate composition of highland barley flour, the characteristics of flour, and the quality of noodles. The results demonstrate that Chaiqing 1 exhibited superior performance in terms of flour quality and noodle texture compared to other varieties. The noodles produced from this variety possessed an outstanding texture, with moderate hardness and excellent elasticity. Additionally, its noodles also exhibited superior cooking resistance and low cooking loss. Nutritionally, the moderate estimated glycemic index (eGI) and high resistant starch (RS) content of Chaiqing 1 were beneficial for intestinal health. Ximalaya 22 showed good processing performance but slightly inferior texture, whereas Kunlun 14 had a high dietary fiber content, which resulted in noodles prone to breaking. Through a comprehensive variety comparison and screening, Chaiqing 1 emerged as the preferred choice for producing high-quality highland barley noodles. Furthermore, correlation analysis revealed that dietary fiber was significantly and positively correlated with water absorption, stability time (ST), and hardness (p < 0.01). Amylose content was associated with peak temperature and breakdown viscosity. This study provides valuable insights into the selection of highland barley varieties for noodle production. Full article

LncRNAs, a type of RNAs exceeding 200 nucleotides (nt) and lacking representative open reading frames (ORFs), have emerged as crucial regulatory molecules that modulate numerous growth and development processes in plants. While substantial progress has been made in interpreting the functions and regulatory mechanisms of coding RNAs, the study of lncRNAs in Tibetan hulless barley remains incomplete. To elucidate the coordination of drought stress responses in Tibetan hulless barely by lncRNAs, we analyzed the previously published RNA-seq data from two cultivars of hulless barley, drought-tolerant (Z772) and drought-sensitive (Z013), subjected to varying durations of drought treatment (0, 1, and 5 h). Initially, we identified a total of 2877 lncRNAs through a strict pipeline, of which 2179 were co-expressed in both cultivars. Additionally, 331 and 367 lncRNAs showed cultivar-specific expression patterns in Z772 and Z013, respectively. Given the trans-regulatory functions of lncRNAs, we utilized WGCNA and uncovered 11 modules that were enriched in drought-responsive pathways. Within these modules, lncRNAs and neighboring PCGs were co-clustered in key control modules. The GO enrichment analysis of potential lncRNA-PCG pairs primarily involved processes related to the response to water deprivation, regulation of abiotic stress, and RNA metabolic processes. Notably, 12 high-confidence lncRNA-PCG pairs displayed concordant expression profiles, with some annotated as TFs. Two of these pairs were validated by qRT-PCR in the Tibetan hulless barley cultivar Kunlun 14. These findings suggested that lncRNAs may participate in regulatory networks involved in drought adaptation in Tibetan hulless barley, offering novel insights into the drought resistance mechanisms of Poaceae crops and potential targets for breeding drought-resistant varieties. Full article

Desert plants in arid regions are facing escalating challenges from global warming, underscoring the urgent need to predict shifts in the distribution and habitats of dominant species under future climate scenarios. This study employed the Maximum Entropy (MaxEnt) model to project changes in the potential suitable habitats of three keystone desert species in Xinjiang—Halostachys capsica (M. Bieb.) C. A. Mey (Caryophyllales: Amaranthaceae), Haloxylon ammodendron (C. A. Mey.) Bunge (Caryophyllales: Amaranthaceae), and Karelinia caspia (Pall.) Less (Asterales: Asteraceae)—under varying climatic conditions. The area under the Receiver Operating Characteristic curve (AUC) exceeded 0.9 for all three species training datasets, indicating high predictive accuracy. Currently, Halos. caspica predominantly occupies mid-to-low elevation alluvial plains along the Tarim Basin and Tianshan Mountains, with a suitable area of 145.88 × 10⁴ km², while Halox. ammodendrum is primarily distributed across the Junggar Basin, Tarim Basin, and mid-elevation alluvial plains and aeolian landforms at the convergence zones of the Altai, Tianshan, and Kunlun Mountains, covering 109.55 × 10⁴ km². K. caspia thrives in mid-to-low elevation alluvial plains and low-elevation alluvial fans in the Tarim Basin, western Taklamakan Desert, and Junggar–Tianshan transition regions, with a suitable area of 95.75 × 10⁴ km². Among the key bioclimatic drivers, annual mean temperature was the most critical factor for Halos. caspica, precipitation of the coldest quarter for Halox. ammodendrum, and precipitation of the wettest month for K. caspia. Future projections revealed that under climate warming and increased humidity, suitable habitats for Halos. caspica would expand in all of the 2050s scenarios but decline by the 2070s, whereas Halox. ammodendrum habitats would decrease consistently across all scenarios over the next 40 years. In contrast, the suitable habitat area of K. caspia would remain nearly stable. These projections provide critical insights for formulating climate adaptation strategies to enhance soil–water conservation and sustainable desertification control in Xinjiang. Full article

The Late Paleozoic granitoids widely distributed in the central section of the East Kunlun Orogenic Belt (EKOB) are responsible for the constraints on its post-collisional extensional processes. We report the whole-rock geochemical compositions, zircon U-Pb ages, and zircon Hf isotope data of granites in the western Kendewula area. The granites, dated between 413.7 Ma and 417.7 Ma, indicate emplacement during the Early Devonian period. The granite is characterized by high silicon content (72.45–78.96 wt%), high and alkali content (7.59–9.35 wt%), high 10,000 × Ga/Al values, and low Al2O3 (11.29–13.32 wt%), CaO (0.07–0.31 wt%), and MgO contents (0.16–0.94 wt%). The rocks exhibit enrichment in large-ion lithophile element (LILE) content and high-field-strength element (HFSE) content, in addition to strong losses, showing significant depletion in Ba, Sr, P and Eu. These geochemical characteristics correspond to A2-type granites. The values of Rb/N and Ba/La and the higher zircon saturation temperature (800~900 °C) indicate that the magma source is mainly crustal, with the participation of mantle materials, although limited. In addition, the zircon εHf(t) values (−4.3–3.69) also support this view. In summary, the A2-type granite exposed in the western Kendewula region formed against a post-collisional extensional setting background, suggesting that the Southern Kunlun Terrane (SKT) entered a post-orogenic extensional phase in the evolution stage since the Early Devonian. The upwelling of the asthenospheric mantle of the crust, triggered by crustal detachment and partial melting, likely contributed to the flare-up of A2-type granite during this period. By studying the nature of granite produced during orogeny, the evolution process of the formation of orogenic belts is discussed, and our understanding of orogenic is enhanced. Full article

The distribution of suitable habitats for medicinal plants is affected by climate, soil, land use, and other factors. Arnebiae Radix, an important traditional Chinese medicinal resource in Xinjiang, includes Arnebia euchroma (Royle) I. M. Johnst. and Arnebia guttata Bunge and is at risk of over-exploitation. This study predicted suitable planting areas by integrating habitat and phytochemical suitability using the MaxEnt model and ArcGIS. The AUC values for A. euchroma and A. guttata were 0.977 and 0.952, with TSS values of 0.829 and 0.725, respectively, validating the high accuracy of the prediction model. Under the current scenario, the areas of suitable habitats for A. euchroma and A. guttata were 108,914 and 176,445 km², mainly distributed along the main mountains in Xinjiang. Under future climate scenarios, the suitable habitat area of A. euchroma increased by 11–18%, except in the ssp126-2090s scenario, while the suitable habitat area of A. guttata area decreased by 3–18%. Both species were influenced by land use/land cover and soil available nitrogen content; additionally, A. euchroma was affected by the precipitation in the driest month, and A. guttata by the mean diurnal range. The content of secondary metabolites was positively correlated with habitat suitability, with soil factors contributing 35.25% to the total secondary metabolite content. Their suitable habitats predominantly occur in grasslands (42–82%). As habitat and phytochemical suitability distributions aligned, the eastern and western sides of the northern Kunlun Mountain Pass emerged as key areas for cultivation. This research can provide a scientific foundation for selecting optimal planting regions for the two Arnebia species. Full article

Snow cover variations significantly affect the stability of regional water supply and terrestrial ecosystems in arid northwest China. This study comprehensively evaluates snow resource changes since 2000 by integrating multisource remote sensing datasets and analyzing four key indicators: snow cover area (SCA), snow phenology (SP), snow depth (SD), and snow water equivalent (SWE). The results reveal a slight downtrend in SCA over the past two decades, with an annual decline rate of 7.13 × 10³ km². The maximum SCA (1.28 × 10⁶ km²) occurred in 2010, while the minimum (7.25 × 10⁵ km²) was recorded in 2014. Spatially, SCA peaked in December in the north and January in the south, with high-altitude subregions (Ili River Basin (IRB), Tarim River Region (TRR), North Kunlun Mountains (NKM), and Qaidam Basin (QDB)) maintaining stable summer snow cover due to low temperatures and high precipitation. Analysis of snow phenology indicates a significant shortening of snow cover duration (SCD), with 62.40% of the study area showing a declining trend, primarily driven by earlier snowmelt. Both SD and SWE exhibited widespread declines, affecting 75.09% and 84.85% of the study area, respectively. The most pronounced SD reductions occurred in TRR (94.44%), while SWE losses were particularly severe in North Tianshan Mountains (NTM, 94.61%). The total snow mass in northwest China was estimated at 108.95 million tons, with northern Xinjiang accounting for 66.24 million tons (60.8%), followed by southern Xinjiang (37.44 million tons) and the Hexi Inland Region (5.27 million tons). Consistency analysis revealed coherent declines across all indicators in 55.56% of the study area. Significant SD and SCD reductions occurred in TRR and Tuha Basin (THB), while SWE declines were widespread in NTM and IRB, driven by rising temperatures and decreased snowfall. The findings underscore the urgent need for adaptive strategies to address emerging challenges for water security and ecological stability in the region. Full article

The southwestern Tarim Basin, shaped by the far-field effects of the India-Eurasia collision, serves as a critical archive for reconstructing source-to-sink dynamics and tectonic evolution in a Cenozoic intracontinental foreland setting. This study presents detrital zircon U-Pb geochronology and trace element data from sands of the Yulongkash and Karakash Rivers, major tributaries of the Hotan River draining the West Kunlun Orogenic Belt. Our results reveal distinct provenance signatures between the two tributaries: Yulongkash river sands (HT1) exhibit dominant Triassic (~208 Ma) and Early Paleozoic (~418 Ma) zircon populations, sourced primarily from the South Kunlun and Tianshuihai terranes, whereas Karakash river sands (MY1) are characterized by Early Paleozoic (~460 Ma) and Precambrian zircons, reflecting predominant contributions from the North Kunlun Terrane. Integration with published datasets highlights systematic spatial variations in detrital zircon age spectra, controlled by bedrock heterogeneity, fluvial geomorphology, and sediment mixing efficiency. Furthermore, crustal thickness reconstructions based on zircon trace elements constrain the terminal closure of the Proto-Tethys Ocean to ~420–440 Ma (peak crustal thickness: ~80 km) and the Paleo-Tethys Ocean to the Late Triassic (~210 Ma). These findings not only refine the provenance framework of the Hotan River drainage system but also provide critical insights into the timing of Tethyan ocean closures and the tectonic evolution of the West Kunlun Orogenic Belt, emphasizing the utility of detrital zircon records in deciphering orogenic histories within complex intracontinental settings. Full article

Twenty-two types of highland barley (HB) raw materials (including 10 common varieties and 5 main planting regions in the Qinghai province) were selected as the experimental materials to investigate their differences in the cooking characteristics, sensory quality, and characteristic flavor of cooked HB. The key volatile flavor components were identified using Gas Chromatography–Ion Mobility Spectroscopy (GC-IMS) combined with relative odor activity value (ROAV) analysis. The results indicated that the highland barley raw materials of Kunlun 15 (M5), Kunlun 14 (M9), Chaiqing 1 (M13) and Kunlun 14 (M14), and Chaiqing 1 (M20) and Kunlun 15 (M21) showed superior cooking quality, texture, and sensory scores. A total of 44 volatile flavor compounds were identified, including 16 aldehydes, 10 alcohols, 9 ketones, 7 esters, 1 acid, and 1 furan. Among these, 13 aldehydes, 4 alcohols, 4 ketones, 7 esters, and 1 furan were found across different cooked HB samples. Notably, ethyl, ethyl 2-methylbutanoate dimer, 2-methylbutanoic acid methyl ester, 2-butanone, 1-octen-3-ol, 1-pentanol dimer, and 2-pentyl furan contributed more significantly to the overall volatile profile. Cluster analysis combining principal component analysis revealed that Kunlun 16 (M16), Kunlun 17 (M17), Kunlun 14 (M18), Kunlun 15 (M19), as well as Chaiqing 1 (M20) and Kunlun 15 (M21), were the most suitable raw materials for cooking due to their better cooking quality, sensory attributes, and flavors, followed by Kunlun 15 (M10) and Kunlun 18 (M12), and Chaiqing 1 (M13) and Kunlun 14 (M14). These findings could help us identify specific HB varieties in corresponding regions with advantages, thus providing a theoretical basis for cooking HB. Full article