The tectonic and geochemical characteristics suggest that the plagiogranitesexposed in the vicinity of Bingdaban on the northern margin of the central Tianshanuplift zone show a distinct mantle-source character, and t...The tectonic and geochemical characteristics suggest that the plagiogranitesexposed in the vicinity of Bingdaban on the northern margin of the central Tianshanuplift zone show a distinct mantle-source character, and their enrichment in LREE andselected enrichment in LILE (large ion lithophile elements) reflect a setting related to anarc tectonic regime. These rocks represent the products formed at shallow levels frommantle-derived magmas modified with subduction components (or super crustal rocks).展开更多
The Southwest Tianshan is the suture zone between the Central Tianshan and the Tarim Craton.To better illustrate the subduction polarity of the Southwest Tianshan Ocean,a systematic detrital zircon LA-ICP-MS U-Pb geoc...The Southwest Tianshan is the suture zone between the Central Tianshan and the Tarim Craton.To better illustrate the subduction polarity of the Southwest Tianshan Ocean,a systematic detrital zircon LA-ICP-MS U-Pb geochronology of sedimentary rocks of the Devonian Apadaerkang Formation and the Carboniferous Akeqiayi Group of the Biedieli area in the Wushi region is the focus.Detrital zircon ages indicate that the youngest grains of the targeted quartz sandstones are Late Devonian and Early Carboniferous in age,respectively.These ages also have relatively similar age spectra,indicating a similar tectonic setting and source in the Biedieli area during the Devonian to Carboniferous.The main spectrum peaks occur at 2360,1960,810,640 and 440 Ma,with a principal age peak in the early Paleozoic(474-430 Ma),and the Central Tianshan Terrane is indicated as the main source.The detrital zircon geochronology and sedimentary characteristics of the Biedieli rocks indicate that the Paleozoic sedimentary rocks in the northern Wushi region were formed at an active continental margin,associated mainly with the early Paleozoic subduction of the South Tianshan Ocean.展开更多
Crustal thickness and Poisson's ratio are key indicators of regional isostasy and material composition.Using teleseismic waveform data from 126 permanent stations and 179 temporary stations in the Pamir-West Tians...Crustal thickness and Poisson's ratio are key indicators of regional isostasy and material composition.Using teleseismic waveform data from 126 permanent stations and 179 temporary stations in the Pamir-West Tianshan region,we obtain the crustal thickness and average Poisson's ratio by the h-κstacking method.The results show that the crust of the Pamir Plateau is thick in the middle and thin on its eastern and western sides,while the West Tianshan region exhibits a"thin-thick-thin"distribution from south to north.The mountainous regions have thicker crust compared to the intermountain basins which feature relatively thinner crust in West Tianshan.Based on the isostasy state analysis of the Airy model,the equilibrium curves of the Pamir and the West Tianshan are similar.The distribution of Poisson's ratio in the study area is characterized by several east-west oriented bands,forming a"high-low-high"distribution pattern as a whole.Joint geophysical and geochemical studies indicate that regions with high Poisson's ratio often have phenomena such as lithospheric subduction and Moho offsets,these areas also display characteristics such as low velocity,high conductivity,and high surface heat flow,which may be related to local melting materials in the middle and lower crust.展开更多
The Sawayaerdun gold deposit is the only extremely large deposit occurring in the giant gold metallogenic belt of the Central Asian Tianshan Orogenic Belt.Breakthroughs in deep and peripheral exploration are of great ...The Sawayaerdun gold deposit is the only extremely large deposit occurring in the giant gold metallogenic belt of the Central Asian Tianshan Orogenic Belt.Breakthroughs in deep and peripheral exploration are of great significance for the sustainable development of the region.In this study,a comprehensive prospecting and exploration model for gold exploration in the high-cold and high-altitude areas of the southwestern Tianshan Mountains was developed by systematically evaluating the metallogenic geological conditions of the deposit and integrating geological,geochemical,and geophysical exploration multi-source data.Both the shallow metamorphic carbonaceous fine clastic rock and ductile shear zones controlled the Au-mineralized zone.Moreover,mineralized alteration,Au-Sb-As element chemical anomalies,high magnetic anomalies,and medium-high values from low-wave impedance were also important components of the model.Three-dimensional(3-D)geological attribute models of various ore-controlling factors were established,revealing the spatial distribution patterns of the deep structural frameworks and hidden mineralization.Geostatistical methods were used to delineate the three edges and two deep-mineral exploration areas.A comprehensive evaluation showed that anomalous variables were well confirmed in geological understanding,highlighting the effectiveness and accuracy of the predictions.These results are significant for deep-edge exploration.展开更多
Water is an indispensable resource for agricultural production.However,its value in agriculture remains largely unknown.This oversight results in agriculture water value being seldom integrated into water pricing,ther...Water is an indispensable resource for agricultural production.However,its value in agriculture remains largely unknown.This oversight results in agriculture water value being seldom integrated into water pricing,thereby restricting the information available for water allocation decisions.In this study,we estimated irrigation water value over the last 30 years on the north slope of the Tianshan Mountains,where agriculture is largely dependent on irrigation water supply.Using a data-parsimonious biophysical framework with a function of crop growth and water-demanding dynamics,we estimate the additional net economic benefit of irrigated agriculture relative to rainfed conditions for three major crops at the county level.Our results reveal that mean irrigation water values were 0.27,0.32,and 0.16 USD m^(-3) for cotton,maize,and wheat,respectively,which were 2.0−3.2 times higher than global estimates.The value of irrigation water significantly increased over time,primarily driven by rising crop prices and improved water use efficiency.Our findings indicate that farmers in arid regions with water limitations may favor crops with high irrigation water use efficiency.Wheat is suggested to be spatially reallocated in light of the economic benefit,given its relatively low output price and water use efficiency.Irrigation water value was more sensitive to precipitation than air temperature by lowering crop prices and narrowing the gap between rain-fed and irrigated yields.The inclusion of irrigation water value in planning could lead to more efficient use of water resources and support decisions regarding irrigation investments,water use rights,and,ultimately,food sustainability.展开更多
The Tianshan orogenic belt has a W-shape, composed of the V-shape Southern Tianshan and Northern Tianshan with different orogenic models .The Southern Tianshan broke off from the Sinian, forming a passive continenta...The Tianshan orogenic belt has a W-shape, composed of the V-shape Southern Tianshan and Northern Tianshan with different orogenic models .The Southern Tianshan broke off from the Sinian, forming a passive continental margin and ocean, and closed during Silurian and Devoaian. It belongs to the Wilson cycle orogenic model. The net duration is about 400 My.The Northern Tianshan began back-arc spreading during Devonian, forming the Devonian-Carboniferous marginal sea, and dosed during Late Carboaiferous. It belongs to the non-Wilson cycle orogeulc model or back-arc orogenic model. The duration is about 100 My .Deformation of the foreland fold-thrust belt occurred in two stages: in the early stage, folds and thrusts were formed by wedge-thrusting and lateral compression, while in the later stage, folds, gravitational normal faults and reveal faults were formed by the uplift of the Tianshan range and by gravity-gliding.展开更多
The determination of total glacial volume is important for the observation of climatic change and its consequences such as global sea-level rise. The tongue area of Glacier No. 4 of Sigong River over Mt. Bogda, easter...The determination of total glacial volume is important for the observation of climatic change and its consequences such as global sea-level rise. The tongue area of Glacier No. 4 of Sigong River over Mt. Bogda, eastern Tianshan was surveyed by ground-penetrating radar （GPR） and real time kinematic （RTK）-global positioning system （GPS） during the summer campaign 2009. In order to calculate the glacier volume, both co-kriging algorithm and estimation based on the theory of perfectly plastic material were employed. Results indicated that the ice-thickness distribution of the investigated glacier ranges from 0 to 105.0 m, with the mean thickness of 27.6 m in 2009. The corresponding ice volume was -0.076 km3 （-0.068 km3 water equivalent）. The bedrock topography shows more undulating than the glacier surface. The difference of the calculated ice volume in this study and the estimated value from the empirical formula is large. Therefore, it is urgent to validate the applicability of the ex- isting empirical formula.展开更多
Rutile is a common Ti-bearing accessory mineral in high pressure （HP） metamorphic rocks of the western Tianshan. Distribution of rutile in the HP rocks varies from 0.5% in the greenschist to 30% in the rutile-bearin...Rutile is a common Ti-bearing accessory mineral in high pressure （HP） metamorphic rocks of the western Tianshan. Distribution of rutile in the HP rocks varies from 0.5% in the greenschist to 30% in the rutile-bearing vein. Rutile can be subdivided into three groups based on the variation of trace elements： The first group has an averaged Zr content of 18 ppm-44 ppm and Hf content of 0.8 ppm-2.4 ppm, which correspond to occurrence of rutile from vein; the second group Zr of 59 ppm-63 ppm, Hf of 3.5 ppm-3.7 ppm; and the third group Zr of 150 ppm-160 ppm and Hf of 3.9 ppm, corresponding to rutile in the matrix of blueschist and eclogite, respectively. Rutile has been retrograded to ilmenite and titanite partly or completely, reducing the value of the ore. But rutile of HP rocks in the western Tianshan usually has the lowest content of uranium （〈1 ppm U）, which might become an attractive raw material for the Ti industry. Therefore, rutile-bearing HP rocks in the western Tianshan as a mineral resource will be the focus of considerable attention.展开更多
Two field surveys on the thickness of Hei Valley No. 8 Glacier （H8） on the southern slope of Mount Bogda in the Tianshan Mountains using ground-penetration radar （GPR） were carried out in August 2008 and Septembe...Two field surveys on the thickness of Hei Valley No. 8 Glacier （H8） on the southern slope of Mount Bogda in the Tianshan Mountains using ground-penetration radar （GPR） were carried out in August 2008 and September 2009. Comparisons of the observed change in glacier thickness using GPR and ablation stakes suggest that GPR observations have high accuracy. Thus, the thickness change for H8 during 2008-2009 was estimated using GPR data. Digital elevation models obtained from topographic maps and the Shuttle Radar Topography Mission were used to analyze ice-elevation changes of H8 between 1 969 and 2 000 m a.s.l.. The results show that H8 has continually thinned, and the thinning rate has increased gradually. The thinning of ablation areas of H8 increased from 0.42a=0.56 m/a in 1969-2000 to 1.474-0.79 m/a in 2000-2008, and then accelerated to 1.924-0.98 m/a in 2008-2009. The retreat of the glacier terminus has had a similar pattern. The distribution of the temperate-ice zone of H8 as determined from GPR data also implies that H8 has experienced strong melting from 2008 to 2009, which indicates that temperature rises have not only enhanced glacial sur- face melting and prolonged melting periods, but also changed the englacial structure and increased the water content of glacier, both of which probably lead to the acceleration of glacial thinning.展开更多
文摘The tectonic and geochemical characteristics suggest that the plagiogranitesexposed in the vicinity of Bingdaban on the northern margin of the central Tianshanuplift zone show a distinct mantle-source character, and their enrichment in LREE andselected enrichment in LILE (large ion lithophile elements) reflect a setting related to anarc tectonic regime. These rocks represent the products formed at shallow levels frommantle-derived magmas modified with subduction components (or super crustal rocks).
基金financially supported by the National Natural Science Foundation of China(Grant Nos.42172258,42072227,U2244205)the Science and Technology Major Project of Xinjiang Uygur Autonomous Region,China(2023A03002)+2 种基金the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(Grant No.2015BAB05B04)the Joint Innovation Fund of China National Uranium Co.,Ltd.,and State Key Laboratory of Nuclear Resources and Environment(Grant No.NRE2021-01)the China Geological Survey(Grant Nos.DD20242868,DZLXJK202206)。
文摘The Southwest Tianshan is the suture zone between the Central Tianshan and the Tarim Craton.To better illustrate the subduction polarity of the Southwest Tianshan Ocean,a systematic detrital zircon LA-ICP-MS U-Pb geochronology of sedimentary rocks of the Devonian Apadaerkang Formation and the Carboniferous Akeqiayi Group of the Biedieli area in the Wushi region is the focus.Detrital zircon ages indicate that the youngest grains of the targeted quartz sandstones are Late Devonian and Early Carboniferous in age,respectively.These ages also have relatively similar age spectra,indicating a similar tectonic setting and source in the Biedieli area during the Devonian to Carboniferous.The main spectrum peaks occur at 2360,1960,810,640 and 440 Ma,with a principal age peak in the early Paleozoic(474-430 Ma),and the Central Tianshan Terrane is indicated as the main source.The detrital zircon geochronology and sedimentary characteristics of the Biedieli rocks indicate that the Paleozoic sedimentary rocks in the northern Wushi region were formed at an active continental margin,associated mainly with the early Paleozoic subduction of the South Tianshan Ocean.
基金granted by the National Science and Technology Major Project of China(No.2024ZD1001100)the National Natural Science Foundation of China(Grant No.41974058)+1 种基金Alliance of International Science Organizations(ANSO)Project under the Belt and Road Initiative(ANSO-CR-PP-2022-04)Key R&D Program of Xinjiang Uyghur Autonomous Region(Grant No.2024B03013-2)。
文摘Crustal thickness and Poisson's ratio are key indicators of regional isostasy and material composition.Using teleseismic waveform data from 126 permanent stations and 179 temporary stations in the Pamir-West Tianshan region,we obtain the crustal thickness and average Poisson's ratio by the h-κstacking method.The results show that the crust of the Pamir Plateau is thick in the middle and thin on its eastern and western sides,while the West Tianshan region exhibits a"thin-thick-thin"distribution from south to north.The mountainous regions have thicker crust compared to the intermountain basins which feature relatively thinner crust in West Tianshan.Based on the isostasy state analysis of the Airy model,the equilibrium curves of the Pamir and the West Tianshan are similar.The distribution of Poisson's ratio in the study area is characterized by several east-west oriented bands,forming a"high-low-high"distribution pattern as a whole.Joint geophysical and geochemical studies indicate that regions with high Poisson's ratio often have phenomena such as lithospheric subduction and Moho offsets,these areas also display characteristics such as low velocity,high conductivity,and high surface heat flow,which may be related to local melting materials in the middle and lower crust.
基金supported by the Science&Technology Fundamental Resources Investigation Program(2022FY101705)China geological survey project(DD20240204805)market prospecting exploration project(CG-2024-HX-S012)。
文摘The Sawayaerdun gold deposit is the only extremely large deposit occurring in the giant gold metallogenic belt of the Central Asian Tianshan Orogenic Belt.Breakthroughs in deep and peripheral exploration are of great significance for the sustainable development of the region.In this study,a comprehensive prospecting and exploration model for gold exploration in the high-cold and high-altitude areas of the southwestern Tianshan Mountains was developed by systematically evaluating the metallogenic geological conditions of the deposit and integrating geological,geochemical,and geophysical exploration multi-source data.Both the shallow metamorphic carbonaceous fine clastic rock and ductile shear zones controlled the Au-mineralized zone.Moreover,mineralized alteration,Au-Sb-As element chemical anomalies,high magnetic anomalies,and medium-high values from low-wave impedance were also important components of the model.Three-dimensional(3-D)geological attribute models of various ore-controlling factors were established,revealing the spatial distribution patterns of the deep structural frameworks and hidden mineralization.Geostatistical methods were used to delineate the three edges and two deep-mineral exploration areas.A comprehensive evaluation showed that anomalous variables were well confirmed in geological understanding,highlighting the effectiveness and accuracy of the predictions.These results are significant for deep-edge exploration.
基金funded by the Third Xinjiang Scientific Expedition Program(Grant No.2021xjkk0800)National Natural Science Foundation of China(Grant No.42401121)+2 种基金Corps International Science and Technology Cooperation Program(Grant No.2024BA004)National Key Research and Development Program of China(Grants No.2025YFE0104900,2023YFD1701803)International Cooperation Program of CRAES(Grant No.2025YSKY-75).
文摘Water is an indispensable resource for agricultural production.However,its value in agriculture remains largely unknown.This oversight results in agriculture water value being seldom integrated into water pricing,thereby restricting the information available for water allocation decisions.In this study,we estimated irrigation water value over the last 30 years on the north slope of the Tianshan Mountains,where agriculture is largely dependent on irrigation water supply.Using a data-parsimonious biophysical framework with a function of crop growth and water-demanding dynamics,we estimate the additional net economic benefit of irrigated agriculture relative to rainfed conditions for three major crops at the county level.Our results reveal that mean irrigation water values were 0.27,0.32,and 0.16 USD m^(-3) for cotton,maize,and wheat,respectively,which were 2.0−3.2 times higher than global estimates.The value of irrigation water significantly increased over time,primarily driven by rising crop prices and improved water use efficiency.Our findings indicate that farmers in arid regions with water limitations may favor crops with high irrigation water use efficiency.Wheat is suggested to be spatially reallocated in light of the economic benefit,given its relatively low output price and water use efficiency.Irrigation water value was more sensitive to precipitation than air temperature by lowering crop prices and narrowing the gap between rain-fed and irrigated yields.The inclusion of irrigation water value in planning could lead to more efficient use of water resources and support decisions regarding irrigation investments,water use rights,and,ultimately,food sustainability.
文摘The Tianshan orogenic belt has a W-shape, composed of the V-shape Southern Tianshan and Northern Tianshan with different orogenic models .The Southern Tianshan broke off from the Sinian, forming a passive continental margin and ocean, and closed during Silurian and Devoaian. It belongs to the Wilson cycle orogenic model. The net duration is about 400 My.The Northern Tianshan began back-arc spreading during Devonian, forming the Devonian-Carboniferous marginal sea, and dosed during Late Carboaiferous. It belongs to the non-Wilson cycle orogeulc model or back-arc orogenic model. The duration is about 100 My .Deformation of the foreland fold-thrust belt occurred in two stages: in the early stage, folds and thrusts were formed by wedge-thrusting and lateral compression, while in the later stage, folds, gravitational normal faults and reveal faults were formed by the uplift of the Tianshan range and by gravity-gliding.
基金supported by the Funds for Creative Research Groups of China (No. 41121001)the National Natural Science Foundation of China (Nos. 41301069, 91025012 and 41101066)+1 种基金the SKLCS founding (Nos. SKLCS-ZZ-2012-01-01, SKLCS-ZZ-2012-01-09)the West Light Program for Talent Cultivation of Chinese Academy of Sciences
文摘The determination of total glacial volume is important for the observation of climatic change and its consequences such as global sea-level rise. The tongue area of Glacier No. 4 of Sigong River over Mt. Bogda, eastern Tianshan was surveyed by ground-penetrating radar （GPR） and real time kinematic （RTK）-global positioning system （GPS） during the summer campaign 2009. In order to calculate the glacier volume, both co-kriging algorithm and estimation based on the theory of perfectly plastic material were employed. Results indicated that the ice-thickness distribution of the investigated glacier ranges from 0 to 105.0 m, with the mean thickness of 27.6 m in 2009. The corresponding ice volume was -0.076 km3 （-0.068 km3 water equivalent）. The bedrock topography shows more undulating than the glacier surface. The difference of the calculated ice volume in this study and the estimated value from the empirical formula is large. Therefore, it is urgent to validate the applicability of the ex- isting empirical formula.
基金funded by the National Natural Science Foundation of China(Nos.41672061,41472059)the State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing
文摘Rutile is a common Ti-bearing accessory mineral in high pressure （HP） metamorphic rocks of the western Tianshan. Distribution of rutile in the HP rocks varies from 0.5% in the greenschist to 30% in the rutile-bearing vein. Rutile can be subdivided into three groups based on the variation of trace elements： The first group has an averaged Zr content of 18 ppm-44 ppm and Hf content of 0.8 ppm-2.4 ppm, which correspond to occurrence of rutile from vein; the second group Zr of 59 ppm-63 ppm, Hf of 3.5 ppm-3.7 ppm; and the third group Zr of 150 ppm-160 ppm and Hf of 3.9 ppm, corresponding to rutile in the matrix of blueschist and eclogite, respectively. Rutile has been retrograded to ilmenite and titanite partly or completely, reducing the value of the ore. But rutile of HP rocks in the western Tianshan usually has the lowest content of uranium （〈1 ppm U）, which might become an attractive raw material for the Ti industry. Therefore, rutile-bearing HP rocks in the western Tianshan as a mineral resource will be the focus of considerable attention.
基金funded by the Project of the Knowledge Inno-vation of Chinese Academy of Sciences(No.KZCX2-YW-GJ04)Postdoctoral Projects of China(Nos.2012M 521817 and 2013M 5320 96)
文摘Two field surveys on the thickness of Hei Valley No. 8 Glacier （H8） on the southern slope of Mount Bogda in the Tianshan Mountains using ground-penetration radar （GPR） were carried out in August 2008 and September 2009. Comparisons of the observed change in glacier thickness using GPR and ablation stakes suggest that GPR observations have high accuracy. Thus, the thickness change for H8 during 2008-2009 was estimated using GPR data. Digital elevation models obtained from topographic maps and the Shuttle Radar Topography Mission were used to analyze ice-elevation changes of H8 between 1 969 and 2 000 m a.s.l.. The results show that H8 has continually thinned, and the thinning rate has increased gradually. The thinning of ablation areas of H8 increased from 0.42a=0.56 m/a in 1969-2000 to 1.474-0.79 m/a in 2000-2008, and then accelerated to 1.924-0.98 m/a in 2008-2009. The retreat of the glacier terminus has had a similar pattern. The distribution of the temperate-ice zone of H8 as determined from GPR data also implies that H8 has experienced strong melting from 2008 to 2009, which indicates that temperature rises have not only enhanced glacial sur- face melting and prolonged melting periods, but also changed the englacial structure and increased the water content of glacier, both of which probably lead to the acceleration of glacial thinning.
