期刊文献+
共找到3,883篇文章
< 1 2 195 >
每页显示 20 50 100
Geochemical Characteristics of the Plagiogranites in the Vicinity of Bingdaban,Central Tianshan.
1
作者 刘良 车自成 刘养杰 《Chinese Journal Of Geochemistry》 EI CAS 1995年第3期243-249,共7页
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
关键词 地球化学特征 天山地区 弧形岛 抬升运动 花岗岩 亲岩元素 富集
在线阅读 下载PDF
Early Paleozoic Tectonic Evolution of the Chinese Southwest Tianshan Orogen:Implications from Detrital Zircon U-Pb Geochronology of the Biedieli Sedimentary Rocks,Northern Wushi Area,NW China
2
作者 HUO Hailong CHEN Zhengle +4 位作者 ZHANG Qing HAN Fengbin ZHANG Wengao WANG Yong WANG Wenbao 《Acta Geologica Sinica(English Edition)》 2025年第1期38-52,共15页
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
关键词 detrital zircon LA-ICP-MS U-Pb Wushi Southwest tianshan
在线阅读 下载PDF
Crustal Thickness and Poisson's Ratio in the Pamir-West Tianshan Region
3
作者 ZHAO Hang WANG Weilai +4 位作者 FANG Lihua LIANG Feng Davlatkhudzha MURODOV LI Siqi BAO Jingjing 《Acta Geologica Sinica(English Edition)》 2025年第6期1575-1585,共11页
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
关键词 crustal thickness localmelting h-κstacking Poisson's ratio Pamir-West tianshan
在线阅读 下载PDF
Exploration Model and Deep-edge Prospecting Prediction of the Sawayaerdun Gold Deposit,Southwest Tianshan
4
作者 SHI Rui WANG Gang +2 位作者 WANG Dongsheng PENG Rong CHEN Zhenghui 《Acta Geologica Sinica(English Edition)》 2025年第6期1788-1803,共16页
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
关键词 Au deposit exploration model deep-edge prediction Sawayaerdun Southwest tianshan Mountains
在线阅读 下载PDF
天山地区GNSS非线性垂直运动驱动因素分析
5
作者 苏广利 熊春宝 +1 位作者 占伟 魏仁杰 《地震研究》 北大核心 2026年第1期84-91,共8页
天山地区GNSS连续站垂直位移时间序列呈现出强烈的季节性、年际及趋势转折等非线性变化。厘清这些非线性变化的驱动因素对形变异常研判、构造活动研究等至关重要。采用GRACE卫星时变重力及环境负荷数据,通过反演负荷形变,识别天山地区G... 天山地区GNSS连续站垂直位移时间序列呈现出强烈的季节性、年际及趋势转折等非线性变化。厘清这些非线性变化的驱动因素对形变异常研判、构造活动研究等至关重要。采用GRACE卫星时变重力及环境负荷数据,通过反演负荷形变,识别天山地区GNSS垂直位移时间序列中的非线性运动信号。结果表明,天山地区GNSS垂直位移季节性变化是由非潮汐大气和海洋负荷以及水文负荷共同影响所致。测站对比及主成分分析方法结果均显示,GRACE卫星重力观测数据反演的负荷形变与GNSS垂直位移时间序列均呈现相似的季节性、年际及趋势转折变化,特别是2018年以后GRACE重力负荷形变与GNSS垂直位移时间序列均出现显著的趋势转折上升,表明天山地区GNSS非线性垂直运动主要是由陆地水储量变化所致,与构造运动无关。天山地区陆地水储量主要受降水和冰川变化两个因素影响,其中降水控制了陆地水储量的季节性变化和年际变化,冰川消融导致了陆地水储量的长期线性减小。 展开更多
关键词 GNSS 非线性垂直运动 陆地水储量 天山 非构造形变
在线阅读 下载PDF
Evolution and Structural Style of Tianshan and Adjacent Basins, Northwestern China 被引量:5
6
作者 Lin Hefu(Eepartment of Energy Resources Geology, China University of Geosciences, Beijing 100083)Liang Huishe (Hebei College Of Geology, Shijiazhuang 050031)Cai Liguo(Eepartment of Energy Resources Geology, China University of Geosciepces, Beijing 100083 《Journal of Earth Science》 SCIE CAS CSCD 1994年第1期46-54,共9页
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
关键词 composite orogeaic belt foreland basin foreland fold-thrust belt tianshan.
在线阅读 下载PDF
Glacier Volume Calculation from Ice-Thickness Data for Mountain Glaciers—A Case Study of Glacier No. 4 of Sigong River over Mt. Bogda, Eastern Tianshan, Central Asia 被引量:4
7
作者 Puyu Wang Zhongqin Li +2 位作者 Wenbin Wang Huilin Li Feiteng Wang 《Journal of Earth Science》 SCIE CAS CSCD 2014年第2期371-378,共8页
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
关键词 ice volume ice-thickness GPR Glacier No. 4 of Sigong River tianshan.
原文传递
Rutile in HP Rocks from the Western Tianshan,China:Mineralogy and Its Economic Implications 被引量:2
8
作者 Wen Su Jilei Li +4 位作者 Qian Mao Jun Gao Xin Liu Fei Chen Xiao-Mei Ge 《Journal of Earth Science》 SCIE CAS CSCD 2018年第5期1049-1059,共11页
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
关键词 Ti resource RUTILE HP vein ECLOGITE western tianshan.
原文传递
东天山早二叠世高镁闪长岩的发现及其构造意义
9
作者 穆合塔尔·麦麦提尼亚孜 肖文交 吴昌志 《岩石学报》 北大核心 2026年第1期169-185,共17页
东天山地区在早二叠世以广泛发育准铝质-过铝质花岗岩、镁铁-超镁铁质侵入岩及相关的铜镍硫化物矿床为显著特征。然而,该时期闪长岩的缺失一直制约着对东天山早二叠世构造-岩浆演化过程的深入理解。新发现的垄东闪长岩为深入研究东天山... 东天山地区在早二叠世以广泛发育准铝质-过铝质花岗岩、镁铁-超镁铁质侵入岩及相关的铜镍硫化物矿床为显著特征。然而,该时期闪长岩的缺失一直制约着对东天山早二叠世构造-岩浆演化过程的深入理解。新发现的垄东闪长岩为深入研究东天山早二叠世构造-岩浆演化过程提供了重要的研究对象。该闪长岩位于东天山中部的沙垄东岩体边部(垄东闪长岩),锆石U-Pb定年结果表明,其形成于早二叠世(275.8±1.6Ma)。主量元素成分显示,垄东闪长岩具有低硅(SiO 2=53.30%~54.87%)、低钾(K_(2)O=0.82%~0.94%)和高镁(MgO=5.83%~10.50%;Mg#=0.61~0.85)、高钠(Na_(2)O=2.60%~3.84%)等特征,属于钠质钙碱性系列的高镁闪长岩。在微量元素组成方面,它表现出富集大离子亲石元素(如Rb、Th、U)和亏损高场强元素(如Nb、Ta、Ti)的特征,同时呈现低Sr、高Y和低Sr/Y比值,与赞岐岩的地球化学特征相似。在同位素组成方面,垄东闪长岩具有亏损的全岩锶同位素[^(87)Sr/^(86)Sr(t)=0.703367~0.703716]、钕同位素[ε_(Nd)(t)=+6.53~+7.81]和锆石铪同位素[ε_(Hf)(t)=+12.40~+15.74]组成,结合其较低Ba含量以及La/Yb、Th/Yb比值,表明其原始岩浆来源于受俯冲洋壳板片脱水流体交代的地幔楔的部分熔融,指示东天山在早二叠世可能仍存在活跃的俯冲板片。综合东天山早二叠世多样的岩浆活动(如MORB、I、S、A型和高镁闪长岩)、大规模岩浆铜镍成矿作用以及右行走滑运动共生特征,本文认为东天山早二叠世岩浆活动与铜镍成矿作用形成于洋脊俯冲环境。 展开更多
关键词 高镁闪长岩 早二叠世 岩石成因 构造意义 东天山
在线阅读 下载PDF
Accelerated Thinning of Hei Valley No. 8 Glacier in the Tianshan Mountains,China 被引量:1
10
作者 武震 刘时银 +1 位作者 张世强 上官冬辉 《Journal of Earth Science》 SCIE CAS CSCD 2013年第6期1044-1055,共12页
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
关键词 Hei Valley No. 8 Glacier (H8) ground-penetrating radar ice-elevation change thinningretreat tianshan.
原文传递
Petrogenesis and Economic Potential of the Sangong MaficUltramafic Intrusion in the Eastern Tianshan, Central Asian Orogenic Belt: Constraints from Mineral, Whole-Rock, and PGE Geochemistry 被引量:1
11
作者 Guochao Zhou Yuwang Wang +5 位作者 Jingbin Wang Yu Shi Hongjing Xie Dedong Li Yong Fu Pan Wu 《Journal of Earth Science》 SCIE CAS CSCD 2024年第3期850-865,共16页
The Sangong Cu-Ni sulfide mineralized mafic-ultramafic intrusion is located on the southern margin of the Bogeda-Harlik belt,eastern Tianshan,China.The intrusion is a well-differentiated complex and is comprised of le... The Sangong Cu-Ni sulfide mineralized mafic-ultramafic intrusion is located on the southern margin of the Bogeda-Harlik belt,eastern Tianshan,China.The intrusion is a well-differentiated complex and is comprised of leucogabbro,gabbro,olivine gabbro,Pl-bearing peridotite,and Pl-bearing pyroxenite.The Pl-bearing pyroxenite hosts both irregularly disseminated sulfide and round droplet sulfide.The intrusive rocks have a wide range of SiO_(2)(42.1 wt.%-50.48 wt.%)and MgO(6.21 wt.%-22.11 wt.%),and are enriched in light rare earth elements(LREE),large-ion lithophile elements(LILE;e.g.,Rb,Ba,Sr,and Pb),and palladium platinum group elements(PPGE)but depleted in high-field-strength elements(HFSE;e.g.,Nb,Ta,and Ti)and iridium PGEs(IPGE).These geochemical characteristics indicate that the Sangong mafic-ultramafic intrusion was derived from high degree of partial melting of depleted mantle and interacted with subduction-related material.The low Pd/Ir(3.21-27.44)but high Ni/Cu(1.64-24.16)ratios,combined with the olivine crystals with low Fo(60.88-78.65)and Ni(54.99 ppm-1688.87 ppm)concentrations suggest that the parental magma of the Sangong intrusion were likely high MgO basaltic in composition that experienced extensive evolution prior emplacement.The Ce/Pb ratios(5.8-13.6)and Nb/U ratios(11.6-30.3)of the intrusive rocks all range between MORB and crustal values,the Nb/Yb and Th/Yb values are close to the lower crust values,together with the low Se/S ratios[(17-100)×10^(-6))]suggest that the magma experienced assimilation not only in mantle source but also in conduit,but the degree of crustal contamination is limited.The Cu/Pd ratios of the rocks range from 3.9×10^(4) to 10.8×10^(4),and the Cu/Zr ratios of Pl-bearing pyroxenite in the Sangong intrusion are>1,combined with the presence of sulfide droplets in the Pl-bearing pyroxenite,indicating the parental magma experienced sulfide saturation and the economical ore bodies may present in the depth of the intrusion.Furthermore,given the discovery of the Baixintan and Yueyawan deposits,we propose the DananhuHarlik belt as an essential prospecting target for Cu-Ni mineralization in North Xinjiang. 展开更多
关键词 Sangong mafic-ultramafic intrusion deposits GEOCHEMISTRY PGE economic potential eastern tianshan.
原文传递
Zircon SHRIMP Dating for the Weiya Pluton, Eastern Tianshan: Its Geological Implications 被引量:60
12
作者 ZHANG Zunzhong GU Lianxing +3 位作者 WU Changzhi LI Weiqiang XI Aihua WANG Shuo 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2005年第4期481-490,共10页
The timing of the emplacement of the Weiya pluton remains controversial due to the absence of systematic and precise dating. This paper reports zircon SHRIMP U-Pb dating of different lithologic phases in the Weiya plu... The timing of the emplacement of the Weiya pluton remains controversial due to the absence of systematic and precise dating. This paper reports zircon SHRIMP U-Pb dating of different lithologic phases in the Weiya pluton, and discusses the genesis and tectonic environment. The ages of gabbro, quartz syenite, diorite porphyrite and fine-grained granite are 236±6 Ma, 246±6 Ma, 233±8 Ma and 237±8 Ma, respectively. All these phases were formed in early-middle Indosinian (Triassic) in a post-orogenic environment. In addition to underplating, intraplating of mantle-derived magmas is also a substantial mechanism for magma generation and vertical accretion of the continental crust. Granitoid rocks are important products of vertical continental accretion as underplating evolves gradually to intraplating. The existence of post-orogenic Indosinian granites shows that the middle Tianshan orogenic belt underwent an important tectonic conversion from the Paleo-Asian ocean subduction-collision system to the Paleo-Tethys ocean regime. 展开更多
关键词 SHRIMP dating POST-OROGENIC INDOSINIAN Weiya pluton eastern tianshan XINJIANG
在线阅读 下载PDF
Carboniferous Post-collisional Rift Volcanism of the Tianshan Mountains, Northwestern China 被引量:52
13
作者 XIA Linqi, XU Xueyi, XIA Zuchun, LI Xiangmin, MA Zhongping and WANG Lishe Xi’an Institute of Geology and Mineral Resources, China Geological Survey, Xi’an, Shaanxi 710054 E-mail: geologyx@pub.xaonline.com. Liu Shuchun and Liu Xinzhu 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2003年第3期338-360,共23页
The Tianshan Carboniferous post-collisional rift volcanic rocks occur in northwestern China as a large igneous province. Based on petrogeochemical data, the Tianshan Carboniferous post-collisional rift basic lavas can... The Tianshan Carboniferous post-collisional rift volcanic rocks occur in northwestern China as a large igneous province. Based on petrogeochemical data, the Tianshan Carboniferous post-collisional rift basic lavas can be classified into two major magma types: (1) the low-Ti/Y type situated in the eastern-central Tianshan area, which exhibits low Ti/Y (<500), Ce/Yb (<15) and SiO2 (43-55%), and relatively high Fe2O3T (6.4-11.5%); (2) the high-Ti/Y type situated in the western Tianshan area, which has high Ti/Y (>500), Ce/Yb (>11) and SiO2 (49-55%), and relatively low Fe2O3T (5.8-7.8%). Elemental data suggest that chemical variations of the low-Ti/Y and high-Ti/Y lavas cannot be explained by fractional crystallization from a common parental magma. The Tianshan Carboniferous basic lavas originated most likely from an OIB-like asthenospheric mantle source (87Sr/86Sr(t) ≈ 0.703-0.705, eNd(0 = +4 to +7). The crustal contamination and continental lithospheric mantle have also contributed significantly to the formation of the basic lavas of the Tianshan Carboniferous post-collisional rift. The silicic lavas were probably generated by partial melting of the crust. The data of this study show that spatial petrogeochemical variations exist in the Carboniferous post-collisional rift volcanics province in the Tianshan region. Occurrence of the thickest volcanics dominated by tholeiitic lavas may imply that the center of the mantle-melting anomaly (mantle plume) was in the eastern Tianshan area at that time. The basic volcanic magmas in the eastern Tianshan area were generated by a relatively high degree of partial melting of the mantle source around the spinel-garnet transition zone, whereas the alkaline basaltic lavas are of the dominant magma type in the western Tianshan area, which were generated by a low degree of partial melting of the mantle source within the stable garnet region, thus the basic lavas of the western Tianshan area might have resulted from relatively thick lithosphere and low geothermal gradient. 展开更多
关键词 Carboniferous post-collisional rift volcanics geochemistry petrogenesis ASTHENOSPHERE lithosphere tianshan Mountains NW China
在线阅读 下载PDF
Paleozoic Accretion-Collision Events and Kinematics of Ductile Deformation in the Eastern Part of the Southern-Central Tianshan Belt, China 被引量:37
14
作者 舒良树 J.Charvet +1 位作者 卢华复 S.C.LAURENT 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2002年第3期308-323,共16页
The Tianshan range could have been built by both late Early Paleozoicaccretion and Late Paleozoic collision events. The late Early Paleozoic Aqqikkudug-Weiya suture ismarked by Ordovician ophiolitic melange and a Silu... The Tianshan range could have been built by both late Early Paleozoicaccretion and Late Paleozoic collision events. The late Early Paleozoic Aqqikkudug-Weiya suture ismarked by Ordovician ophiolitic melange and a Silurian flysch sequence, high-pressure metamorphicrelics, and mylonitized rocks. The Central Tianshan belt could principally be an Ordovician volcanicarc; whereas the South Tianshan belt, a back-arc basin. Macro- and microstructures, along withunconformities, provide some kinematic and chronological constraints on 2-phase ductile deformation.The earlier ductile deformation occurring at ca. 400 Ma was marked by north-verging ductileshearing, yielding granulite-bearing ophiolitic melange blocks and garnet-pyroxene-facies ductiledeformation, and the later deformation, a dextral strike-slip tectonic process, occurred during theLate Carboniferous-Early Permian. Early Carboniferous molasses were deposited unconformably onpre-Carboniferous metamorphic and ductilely sheared rocks, implying the end of the early orogeny.The large-scale ductile strike-slip along the Aqqikkudug-Weiya zone was possibly caused by thesecond tectonic event, the Hercynian collision between the northern Tarim block and the southernSiberian block. Late Paleozoic granitic magmatism and superimposed structures overprinted this EarlyPaleozoic deformation belt. Results of geometric and kinematic studies suggest that the primaryframework of the Southern-Central Tianshan belt, at least the eastern part of the Tianshan belt, wasbuilt by these two phases of accretion events. 展开更多
关键词 KINEMATICS ductile deformation collision-accretion PALEOZOIC Southern-Central tianshan belt
在线阅读 下载PDF
A Large-Scale Palaeozoic Dextral Ductile Strike-Slip Zone:the Aqqikkudug-Weiya Zone along the Northern Margin of the Central Tianshan Belt,Xinjiang,NW China 被引量:39
15
作者 CHARVET Jacques 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1999年第2期148-162,共15页
Abstract The nearly E-W-trending Aqqikkudug-Weiya zone, more than 1000 km long and about 30 km wide, is an important segment in the Central Asian tectonic framework. It is distributed along the northern margin of the ... Abstract The nearly E-W-trending Aqqikkudug-Weiya zone, more than 1000 km long and about 30 km wide, is an important segment in the Central Asian tectonic framework. It is distributed along the northern margin of the Central Tianshan belt in Xinjiang, NW China and is composed of mylonitized Early Palaeozoic greywacke, volcanic rocks, ophiolitic blocks as a mélange complex, HP/LT-type bleuschist blocks and mylonitized Neoproterozoic schist, gneiss and orthogneiss. Nearly vertical mylonitic foliation and sub-horizontal stretching lineation define its strike-slip feature; various kinematic indicators, such as asymmetric folds, non-coaxial asymmetric macro- to micro-structures and C-axis fabrics of quartz grains of mylonites, suggest that it is a dextral strike-slip ductile shear zone oriented in a nearly E-W direction characterized by “flower” strusture with thrusting or extruding across the zone toward the two sides and upright folds with gently plunging hinges. The Aqqikkudug-Weiya zone experienced at least two stages of ductile shear tectonic evolution: Early Palaeozoic north vergent thrusting ductile shear and Late Carboniferous-Early Permian strike-slip deformation. The strike-slip ductile shear likely took place during Late Palaeozoic time, dated at 269±5 Ma by the40Ar/39Ar analysis on neo-muscovites. The strike-slip deformation was followed by the Hercynian violent S-type granitic magmatism. Geodynamical analysis suggests that the large-scale dextral strike-slip ductile shearing is likely the result of intracontinental adjustment deformation after the collision of the Siberian continental plate towards the northern margin of the Tarim continental plate during the Late Carboniferous. The Himalayan tectonism locally deformed the zone, marked by final uplift, brittle layer-slip and step-type thrust faults, transcurrent faults and E-W-elongated Mesozoic-Cenozoic basins. 展开更多
关键词 ductile thrusting dextral strike-slipping kinematic analysis Aqqikkudug-Weiya zone tianshan Palaeozoic orogenic belt
在线阅读 下载PDF
Glacier area variation and climate change in the Chinese Tianshan Mountains since 1960 被引量:34
16
作者 WANG Shengjie ZHANG Mingjun +4 位作者 LI Zhongqin WANG Feiteng LI Huilin LI Yaju HUANG Xiaoyan 《Journal of Geographical Sciences》 SCIE CSCD 2011年第2期263-273,共11页
Based on the statistics of glacier area variation measured in the Chinese Tianshan Mountains since 1960, the response of glacier area variation to climate change is discussed systematically. As a result, the total are... Based on the statistics of glacier area variation measured in the Chinese Tianshan Mountains since 1960, the response of glacier area variation to climate change is discussed systematically. As a result, the total area of the glaciers has been reduced by 11.5% in the past 50 years, which is a weighted percentage according to the glacier area variations of 10 drainage basins separated by the Glacier Inventory of China (GIC). The annual percentage of area changes (APAC) of glaciers in the Chinese Tianshan Mountains is 0.31% after the standardization of the study period. The APAC varies widely for different drainage basins, but the glaciers are in a state of rapid retreat, generally. According to the 14 meteorological sta- tions in the Chinese Tianshan Mountains, both the temperature and precipitation display a marked increasing tendency from 1960 to 2009 at a rate of 0.34℃·(10a)^-1 and 11 mm·(10a)^-1, respectively. The temperature in the dry seasons (from November to March) increases rapidly at a rate of 0.46℃·(10a)^-1, but the precipitation grows slowly at 2.3 mm·(10a)^-1. While the temperature in the wet seasons (from April to October) grows at a rate of 0.25℃·(10a)^-1, but the precipitation increases at 8.7 mm·(10a)^-1, The annual and seasonal climatic trends accelerate the retreat of glaciers. 展开更多
关键词 Chinese tianshan Mountains glacier area climate change temperature PRECIPITATION
原文传递
Re-Os Age of Cu-Ni Ores from the Huangshandong Cu-Ni Sulfide Deposit in the East Tianshan Mountains and Its Implication for Geodynamic Processes 被引量:28
17
作者 MAOJingwen YANGJianmin +3 位作者 QUWenjun DUAndao WANGZhiliang HANChunming 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2003年第2期220-226,共7页
An isochron age of 282±20 (95% conf. limit) Ma of the sulfide ores in the Huangshandong Cu-Ni sulfide deposit, the East Tianshan Mountains has been obtained through Re-Os isotopic measurement. The age implies tha... An isochron age of 282±20 (95% conf. limit) Ma of the sulfide ores in the Huangshandong Cu-Ni sulfide deposit, the East Tianshan Mountains has been obtained through Re-Os isotopic measurement. The age implies that the Cu-Ni sulfide deposit and other related deposits in the same area occurred in a Permian extensional environment of post-collision instead of Devonian-Early Carboniferous ophiolite-related oceanic or island arc environments inferred before. It shares the same ages with the orogenic and epithermal gold deposit systems in the same area. An initial 187Os/188Os ratio of 0.25±0.04 (1σ) and a γos value of 99 on average display the participation of large quantities of crustal components into the rock-forming and ore-forming system during mineralization and magmatic emplacement. 展开更多
关键词 Huangshandong Cu-Ni sulfide deposit East tianshan mountains PERMIAN Re-Os age
在线阅读 下载PDF
Geochemistry and SHRIMP Zircon U-Pb Age of Post-Collisional Granites in the Southwest Tianshan Orogenic Belt of China:Examples from the Heiyingshan and Laohutai Plutons 被引量:23
18
作者 LONG Lingli GAO Jun +5 位作者 WANG Jingbin QIAN Qing XIONG Xianming WANG Yuwang WANG Lijuan GAO Liming 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2008年第2期415-424,共10页
The Heiyingshan granite and the Laohutai granite plutons exposed in the Southwest Tianshan resemble A-type granites geochemically. Analysis shows that the both are ferron calc-alkalic peraluminous or ferron alkali-cal... The Heiyingshan granite and the Laohutai granite plutons exposed in the Southwest Tianshan resemble A-type granites geochemically. Analysis shows that the both are ferron calc-alkalic peraluminous or ferron alkali-calcic peraluminous with a relatively high concentration of SiO2 (〉70%), high alkali contents (Na20 + K20 = 7.14%-8.56%; K20〉N20; A/CNK = 0.99-1.20), and pronounced negative anomales in Eu, Ba, St, P and Ti. A SHRIMP zircon U-Pb age of 285±4 Ma was obtained for the Heiyingshan hornblende biotite granite intrusion. The geochemical and age dating data reported in this paper indicate that these granites were formed during the post-collisional crustal extension of the Southwest Tianshan orogenic belt, in agreement with the published data for the granites in the South Tianshan. 展开更多
关键词 Xinjiang Southwest tianshan granite GEOCHEMISTRY SHRIMP zircon U-Pb age
在线阅读 下载PDF
Geological Characteristics and Zircon U-Pb Dating of Volcanic Rocks from the Beizhan Iron Deposit in Western Tianshan Mountains, Xinjiang, NW China 被引量:32
19
作者 ZHANG Zuoheng HONG Wei +5 位作者 JIANG Zongsheng DUAN Shigang XU Lingang LI Fengming GUO Xincheng ZHAO Zhengang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2012年第3期737-747,共11页
The Beizhan large iron deposit located in the east part of the Awulale metallogenic belt in the western Tianshan Mountains is hosted in the Unit 2 of the Dahalajunshan Formation as lens, veinlets and stratoid, and bot... The Beizhan large iron deposit located in the east part of the Awulale metallogenic belt in the western Tianshan Mountains is hosted in the Unit 2 of the Dahalajunshan Formation as lens, veinlets and stratoid, and both of the hanging wall and footwall are quartz-monzonite; the dip is to the north with thick and high-grade ore bodies downwards. Ore minerals are mainly magnetite with minor sulfides, such as pyrite, pyrrhotite, chalcopyrite and sphalerite. Skarnization is widespread around the ore bodies, and garnet, diopside, wollastonite, actinolite, epidote, uralite, tourmaline sericite and calcite are ubiquitous as gangues. Radiating outwards from the center of the ore body the deposit can be classified into skarn, calcite, serpentinite and marble zones. LA-ICP-MS zircon U-Pb dating of the rhyolite and dacite from the Dahalajunshan Formation indicates that they were formed at 301.3±0.8 Ma and 303.7±0.9 Ma, respectively, which might have been related to the continental arc magmatism during the late stage of subduction in the western Tianshan Mountains. Iron formation is genetically related with volcanic eruption during this interval. The Dahalajunshan Formation and the quartz-monzonite intrusion jointly control the distribution of ore bodies. Both ore textures and wall rock alteration indicate that the Beizhan iron deposit is probably skarn type. 展开更多
关键词 iron ore Zircon U-Pb dating SKARNIZATION Beizhan Western tianshan Mountains
在线阅读 下载PDF
Polyphase Tectonic Events and Cenozoic Basin-Range Coupling in the Tianshan Belt,Northwestern China 被引量:23
20
作者 SHULiangshu WANGBo +3 位作者 YANGFan LUHuafu J.CHARVET S.LAURENT-CHARVET 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2003年第4期457-467,共11页
Studies show that the Tianshan orogenic belt was built in the late stage of the Paleozoic, as evidenced by the Permian red molasses and foreland basins, which are distributed in parallel with the Tianshan belt, indica... Studies show that the Tianshan orogenic belt was built in the late stage of the Paleozoic, as evidenced by the Permian red molasses and foreland basins, which are distributed in parallel with the Tianshan belt, indicating that an intense folding and uplifting event took place. During the Triassic, this orogenic belt was strongly eroded, and basins were further developed. Starting from the Jurassic, a within-plate regional extension occurred, forming a series of Jurassic-Paleogene extensional basins in the peneplaned Tianshan region. Since the Neogene, a collision event between the Indian and the Eurasian plates that took place on the southern side of the Tianshan belt has caused a strong intra-continental orogeny, which is characterized by thrusting and folding. Extremely thick coarse conglomerate and sandy conglomerate of the Xiyu Formation of Neogene System were accumulated unconformably on the Tianshan piedmont. Studies have revealed that the strong compression caused by the Indian-Eurasian collision had a profound influence over the orogenic belt in the hinterland, and MesozoiC-Cenozoic brittle deformed structures superposed on the ductile deformed Paleozoic rocks. The Mesozoic extensional basins were converted into Cenozoic compressional basins. The deformation in the basins is featured by step thrusts and fault-related folds. Statistics of joints show that the principal compressive stress since the Neogene is in a N-S direction. Meanwhile, owing to the underthrusting of the basin toward the orogenic belt, the Paleozoic strata were thrust on the Meso-Cenozoic rocks as tectonic slices, revealing distinct kinematic features in different geologic units. The basin-range coupling zones are characterized by intensive compression, folding and thrusting, accompanied by local sub-E-W-trending strike-slip faults. In the Tianshan region, Cenozoic thrusting is the most common basin-range coupling mode. The folding and faulting of Mesozoic sedimentary rocks, spontaneous combustion of Jurassic coal layers and formation of sintered rocks, the Cenozoic earthquakes and active faulting, and the unique mosaic pattern of basin-range framework of Xinjiang are all products of tectonism since the Neogene. 展开更多
关键词 intracontinental deformation polyphase deformation structure basin-range coupling CENOZOIC tianshan region
在线阅读 下载PDF
上一页 1 2 195 下一页 到第
使用帮助 返回顶部