Multistage tungsten mineralization was recently discovered in the Mamupu copper-polymetallic deposit in the southern Yulong porphyry copper belt(YPCB),Tibet.This study reports the results of cathodoluminescence,trace ...Multistage tungsten mineralization was recently discovered in the Mamupu copper-polymetallic deposit in the southern Yulong porphyry copper belt(YPCB),Tibet.This study reports the results of cathodoluminescence,trace element and Sr isotope analyses of Mamupu scheelite samples,undertaken in order to better constrain the mechanism of W mineralization and the sources of the ore-forming fluids.Three different types of scheelite are identified in the Mamupu deposit:scheelite A(Sch A)mainly occurs in breccias during the prograde stage,scheelite B(Sch B)forms in the chlorite-epidote alteration zone in the retrograde stage,while scheelite C(Sch C)occurs in distal quartz sulfide veins.The extremely high Mo content and negative Eu anomaly in Sch A represent high oxygen fugacity in the prograde stage.Compared with ore-related porphyries,Sch A has a similar REE pattern,but with higher ΣREE,more depleted HREE and slightly lower(^(87)Sr/^(86)Sr)i ratios.These features suggest that Sch A is genetically related to ore-related porphyries,but extensive interaction with carbonate surrounding rocks affects the final REE and Sr isotopic composition.Sch B shows dark(Sch B-I)and light(Sch B-II)domains under CL imaging.From Sch B-I to Sch B-II,LREEs are gradually depleted,with MREEs being gradually enriched.Sch C has the highest LREE/HREE ratio,which indicates that it inherited the geochemical characteristics of fluids after the precipitation of HREE-rich minerals,such as diopside and garnet,in the early prograde stage.The Mo content in Sch B and Sch C gradually decreased,indicating that the oxygen fugacity of the fluids changed from oxidative in the early stages to reductive in the later,the turbulent Eu anomaly in Sch B and Sch C indicating that the Eu anomaly in the Mamupu scheelite is not solely controlled by oxygen fugacity.The extensive interaction of magmatic-hydrothermal fluids and carbonate provides the necessary Ca^(2+)for the precipitation of scheelite in the Mamupu deposit.展开更多
Glaciers, with their unique and spectacular appearances and rich and varied terrain, have received widespread attention and become important tourist attractions. This paper uses the travel cost method to estimate the ...Glaciers, with their unique and spectacular appearances and rich and varied terrain, have received widespread attention and become important tourist attractions. This paper uses the travel cost method to estimate the recreational value of the glacier tourism resources of Yulong Snow Mountain(also called Jade Dragon Snow Mountain), which is the most developed glacier tourist attraction in China. First-hand information was obtained through field surveys, and the travel costs of visitors visiting the Yulong Snow Mountain glacier were calculated before the method was applied to evaluate the recreational value of the focal glacier resource. The results show that the Yulong Snow Mountain consumer surplus associated with its glacier resources in 2016 ranged from 645.59-3439.10 million CNY, and the total recreational value ranged from 1.97-8.17 billion CNY. Approaches allocating travel costs across multiple recreational sites, however, can vary, and there is large difference in estimated results depending on used approaches. Nevertheless, the results of the analysis can help understand the socio-economic value of glacier resources and provide a reference for their development and protection.展开更多
The glacier on the Yulong Mountain is one of the most important attractions in Lijiang, Yunnan, China. But it keeps retreating these years due to global warming, which is bound to influence regional tourism significan...The glacier on the Yulong Mountain is one of the most important attractions in Lijiang, Yunnan, China. But it keeps retreating these years due to global warming, which is bound to influence regional tourism significantly in Lijiang. This study estimates the effects of the glacier retreat of the Yulong Mountains on tourism there. Primary data were collected through a visitor survey including demographics, motives, lengths of stay, and opinions about each tourism resource from tourists to Lijiang, as well as questions about which scenic spot(s) they had visited or would visit, how much they expended per day during their visit and how their visiting behavior would be changed upon the hypothesis that the glacier would disappear. These data were used to analyze the proportion of the contribution of glacier to the tourism in Lijiang and estimate the impact of glacier on the regional tourism quantitatively. According to the survey, it could be concluded that three quarters of the tourists to Lijiang were interested in the Yulong Mountain glacier, indicating that the glacier possesses notable appeal for sightseeing tourists. The results of our analysis showed that about 689,013-1,508,247 tourists, accounting for 19.63-42.97 % of the total 3,510,000 domestic tourists to Lijiang in 2004, would not come to Lijiang in the absence of the glacier, resulting in a possible direct economic loss of 84,382,508-184,713,011 USD (viz. 700,374,824-1,533,117,993 RMB) and a markedly decrease in the attraction radius.展开更多
The Mamupu skarn-type Cu-Au polymetallic deposit represents the first discovery of a medium deposit in the southern Yulong porphyry copper belt(YPCB),eastern Tibet.The Cu-Au mineralization mainly occurs as chalcopyrit...The Mamupu skarn-type Cu-Au polymetallic deposit represents the first discovery of a medium deposit in the southern Yulong porphyry copper belt(YPCB),eastern Tibet.The Cu-Au mineralization mainly occurs as chalcopyrite in breccia,within the plate-like carbonate interlayer,being closely related to chloritization(e.g.,chlorite,magnetite and epidote)and skarnization(e.g.,diopside,tremolite and garnet).The ore-related quartz syenite porphyry(QSP)and granodiorite porphyry(GP)were emplaced at 40.1±0.2 Ma and 39.9±0.3 Ma,respectively.The QSP of Mamupu is an alkaline-rich intrusion,relatively enriched in LREE,LILE,depleted in HFSE,with no significant negative Eu and Ce anomalies,slightly high(^(87)Sr/^(86)Sr)i,lowε_(Nd)(t),uniform(^(206)Pb/^(204)Pb)i andε_(Hf)(t)values,which indicates that the porphyry magma may be caused by both the mixing of metasomatized EM II enriched mantle and thickened juvenile lower crust.The QSP in the Mamupu deposit shares a similar genesis of petrology to other ore-related porphyries within the YPCB.High oxygen fugacity and water content of the magmas are essential for the formation of porphyry and skarn Cu deposits.The QSP has similar high magmatic oxidation states and water content to the Yulong deposit,which indicates that the Mamupu has a high prospecting potential.Differences in the geological characteristics and scale of mineralization between the Mamupu and other YPCB deposits may be due to the different emplacement depths of ore-related intrusions,as well as differences in the surrounding rocks.展开更多
Based on the data of δ^18O in surface snow, snow pits, meltwater and the glacier-fed fiver water at Baishui Glacier No. 1, Mt. Yulong, the isotopic fractionation behaviors in the typical monsoonal temperate glacier s...Based on the data of δ^18O in surface snow, snow pits, meltwater and the glacier-fed fiver water at Baishui Glacier No. 1, Mt. Yulong, the isotopic fractionation behaviors in the typical monsoonal temperate glacier system in winter and summer were compared. The results indicate that the isotopic fractionation degree in summer is greater than that in winter, suggesting that the snow/ice melting is more intense in summer. Moreover, whenever it is in winter or summer, from surface snow to meltwater, and to glacier-fed fiver water, the gradient of δ^18O with altitude gradually increases. This shows that the degree of isotopic fractionation gradually strengthens when surface snow is being converted into meltwater and finally into glacial fiver water, which suggests that the influence of post-depositional processes on δ^18O gradient in the monsoonal temperate glacier region differs spatially.展开更多
The Yulong supper\|large copper deposit is situated within the well\|known S\|N striking Yulong copper\|molybdenum ore belt. The ore\|bearing biotite\|monogranitic porphyry was emplaced within clastic rocks (mainly sh...The Yulong supper\|large copper deposit is situated within the well\|known S\|N striking Yulong copper\|molybdenum ore belt. The ore\|bearing biotite\|monogranitic porphyry was emplaced within clastic rocks (mainly shales and siltstones) of the Jiapila Formation (T 3 j ) and carbonate rocks of the Bolila Formation (T 3 b ) of the Upper Triassic. Five mineralization patterns have been recognized in the deposit, i.e., ①veinlet\|disseminated Cu\|Mo ore in the porphyry; ②skarn\|type Cu ore at the contact zone with carbonates (T 3 b ); ③stratiform\|like oxidized Cu ore between T 3 b carbonate rocks and T 3 j hornstones; ④brecciated Cu ore at the local periphery of porphyry; and ⑤vein Pb\|Zn\|Ag ore in the outer contact zone. They constitute a unique integrated polymetal mineralization series of epigenetic intermediate\|acid magmatic hydrothermal system.Studies have shown that the Yulong deposit was the coupling product of sedimentation, magmatism, and tectonism. The Cu\|bearing sandstones in the Japila Formation have provided partial ore\|bearing materials for the porphyry mineralization during the Himalayan period. The mineralized porphyry mass was passively emplaced and controlled by a nose\|like anticlinal trap opening to the north. The interlayered fractured zone formed during folding between the Jiapila and Bolila Formations acted as favorable host space for stratiform\|like skarn and oxidized ores. A large number of cleavages and fissures developed during folding provided both conduits for the circulation of ore\|forming fluids and host spaces for Pb\|Zn\|Ag ore veins. The veinlet\|disseminated Cu\|Mo ore in the porphyry mass owns the characteristics of typical porphyry copper deposits in the world. The veinlet\|disseminated ore body and the stratiform\|like skarn\|type and/or oxidized ore body, the two main ore bodies in Yulong, are connected with each other and shown as “mushroom\|like" shape, in which the former occurs as “mushroom stem" and the latter as “mushroom cover".展开更多
The zone of Yulong copper deposit is considered superlarge in scale all over the world, which is a part of Tethys to Himalaya Ore\|forming zone. The geological background of the Jinshajiang and Lancangjiang Faults pro...The zone of Yulong copper deposit is considered superlarge in scale all over the world, which is a part of Tethys to Himalaya Ore\|forming zone. The geological background of the Jinshajiang and Lancangjiang Faults provided utility for accumulated of copper, molybdenum and so on. The Yulong copper zone is the most important characteristic in the east Qinghai—Xizang Plateau (Tibet), which isabout 400km in length from north to south, and 30~70km in width from east to west. The structural channel for ores accumulation was constructed in Yanshan orogeny and the process of ore forming of the zone was mainly in Himalaya orogeny. The Yulong copper zone can be divided into three subzones, each named as north, south and east subzone which the north subzone is 50km in length of about NNW direction. Based on the geological interpretation (Fig.1), we understood that NW structures are distributed mainly in this area, then EW and NNW, and the sigmoid structures extended reflect their extrusion character. The EW and NNW structures are distributed in small scale and extended stable, which are cut to each other. The NNW structure was interpreted as undercover fracture, which may occurred earlier than NW one. Beside, of the structure, there are some differences in image tone, linear, relief, strata combination, structure pattern and so on. Therefore, the undercover fault played key efforts to Yulong copper formation.展开更多
The Yulong and Haba snowcapped ranges in the southeast side of the Qinghai—Xizang (Tibet) Plateau are situated structurally in a corner between the Dianxi Block to the west, the Yangzi Landmass to the southeast and S...The Yulong and Haba snowcapped ranges in the southeast side of the Qinghai—Xizang (Tibet) Plateau are situated structurally in a corner between the Dianxi Block to the west, the Yangzi Landmass to the southeast and Songpan—Ganzi folded belts to the north. Deformations in this area are strongly effected by the Tethys—Himalaya movement and defined by the Jinshajiang\|Honghe fault in the west and the Xiaojinhe fault in the southeast. A Jinshajiang river cut through in the middle with about 200 meters drop height that gives an exposed cross section.The Yulong—Haba range is an N—S trending anticline (F 3/D 3) comprising a metamorphic core of unknown ages and a sedimentary cover from mid\| Devonian onwards. Contact between the metamorphic core and the cover sequence is structurally. Although there is no evidence being found for the unconformity interface, deformation in the core, dominated by mica\|quartz schists, phyllites and quartzite, and the cover rocks, dominated by marbles, are different. The core rocks underwent a metamorphism with well developed foliations (S 1/D 1) in a greenschist facies condition. Occasionally an intrafolial fold (F 1, folded S 0) present in the S 1 layering. The S1 foliation was re\|folded by recumbent folds (F 2/D 2). Orientations of the axes of F 2 recumbent folds, the crenulation and mineral lineations now are shallowly plunged to S or N with angles less than 20° since the intensity of the D 3 deformation, during which both the core and cover rocks are involved to form the regional upright F 3 fold. All of the L\|S fabrics formed during D 2 in the core rocks are cut off by a set of near E—W or SWW—NEE trending normal faults that showing a top to the SSE extensional movement occurred during the D 3 event as a result of syn\|thickening extension (D 3′). Deformations D 4 are characterized by (1) numbers of near S—N trending high\|angle normal faults, and (2) interlayer gliding in the cover rocks, and lower angle detachment zones in the contact. Movement indicators in the D 4 structures showing a NEE in the east side of the F 3 fold, and a SWW in the west side, normal sense of shear that demonstrated a post\|thickening extension in the area.展开更多
During the summers of 1999 and 2000, sampling was carried out in Mt. Yulong, for the investigation of the spatial distribution of oxygen stable isotope in the atmospheric glacial hydro system and similar results obt...During the summers of 1999 and 2000, sampling was carried out in Mt. Yulong, for the investigation of the spatial distribution of oxygen stable isotope in the atmospheric glacial hydro system and similar results obtained in the two years have confirmed our conclusion. There is an evident negative correlation between stable isotopic composition and air temperature precipitation amount, suggesting that there exits a strong 'precipitation amount effect' in this typical monsoon temperate glacier region. There are marked differences between the δ 18 O values in winter accumulated snow, glacial meltwater, summer precipitation and glacier feeding stream. Under the control of varied climatic conditions, spatial and temporal variations of above glacial hydro mediums are apparent. Isotopic depletion or fractionation and ionic changes had occurred during the phase change and transformation processes of snow ice, ice meltwater, flowing of runoff and contact with bedrock. The variation of stable isotope in a runoff can reflect not only its own flowing process but also its different feeding sources.展开更多
Extending in a NNW-SSE direction. the Yulong porphyry copper belt is the largest and richest porphyry copper belt in China, originating in the Paleogene. Tectonically located on the eastern margin of the northern Tibe...Extending in a NNW-SSE direction. the Yulong porphyry copper belt is the largest and richest porphyry copper belt in China, originating in the Paleogene. Tectonically located on the eastern margin of the northern Tibet geodepression. and nearly 500 km of the Himalayan Yarlung Zangbo plate subduction zone of nearly E-W trend. it is a relatively typical intracontinental rejuvenated platform-type porphyry copper belt. Ore-bearing porphyry masses in the belt mainly represented by monzogranite-porphyry occurring as stocks in variegated sandshale of the lower Upper Triassic Jiapila Fromation and its overlying and underlying copper-bearing strata. They are characterized by enrichment in K. CI and LREE. abundant fluid inclusions and a distinct porphyroblastic texture. The oxygen. hydrogen. strotium. lead and sulfur isotopic values of the rock show the feature of crust-mantle mixing.The Orebodies are plpe-shaped stratoid; the mineralization is dominated by Cu and Mo, accompanied by Fe. Co. Au. Ag. Bi. W. Pb. Zn. and Pt-group elements. Alteration is strong. marked mainly by potassic alteration, silicification. skarnization and propylitization. The formation of this type of deposit largely progressed through two stages. The first stage was the stage of formation of Cu-bearing source beds. It occurred in the Triassic. when a transgressive copper-bearing formation was deposited on the western margin of the Qamdo Bay. which was represented by intermediate-acid volcanic rocks and variegated sandshale in the lower part. dolomitic carbonate rocks in the middle and black carbonaceous sandshale in the upper part. In the second stage. composite porphyry copper deposits were formed. This stage took place in the Paleogene. when this district was in a stage of platform rejuvenation. forming a series of NNW-trending deep faults. so that Na, K. Cl. H2O and CO2-rich hydrothermal fluids from the depths were injected into the upper crust and replaced and melted copper-bearing sialic rocks of the upper crust. e. g. the Triassic copper-bearing rock series in the Yulong area. to form porphyroblastic cooper-bearing intermediate-acid porphyry.展开更多
蚀变分带和成矿机制的准确厘定是建立斑岩成矿模型与找矿预测的关键。本文以新生代金沙江-哀牢山成矿带的玉龙斑岩铜矿为例,通过质量作用定律(LMA)和吉布斯自由能最小化模型(GEM),构建含矿热液与斑岩侵入体的pH-f O 2相图和动态传输模型...蚀变分带和成矿机制的准确厘定是建立斑岩成矿模型与找矿预测的关键。本文以新生代金沙江-哀牢山成矿带的玉龙斑岩铜矿为例,通过质量作用定律(LMA)和吉布斯自由能最小化模型(GEM),构建含矿热液与斑岩侵入体的pH-f O 2相图和动态传输模型,以揭示蚀变分带成因和金属成矿机制。LMA与GEM结果显示初始成矿流体pH值为4.7,logf_(O2)=-23.0(ΔFMQ=+2.7),且溶解Cu含量为1138×10^(-6),Mo为1.2×10^(-6)。研究表明,当该酸性及强氧化性流体流入二长花岗斑岩体时,在温度为450~360℃范围内,代表钾硅酸盐化蚀变的钾长石、黑云母、硬石膏、赤铁矿和磁铁矿的矿物逐渐沉淀,且与钾硅酸盐化蚀变相关流体具有较高pH值(5.0~7.0)和氧逸度(ΔFMQ=+2.9~+3.6)特征;当温度在360~320℃范围时,代表青磐岩化蚀变阶段的典型矿物如绿帘石、铁绿泥石和斜绿泥石等逐渐形成,流体pH值(5.0~6.4)和氧逸度(ΔFMQ=+1.1)均有所下降;当温度进一步从320℃下降到200℃时,流体pH值(5.0~5.7)进一步小幅下降,而氧逸度则(ΔFMQ=+1.7)略有回升,在此期间,绢云母和方解石等开始沉淀并形成典型的绢英岩化蚀变。此外,以HMoO_(4)^(-)和MoO_(4)^(2-)为载体的Mo在狭窄高温区间(450~370℃)内沉淀,而以CuCl(CuCl_(4)^(3-)、CuCl_(2)^(-)、CuCl)为主要载体的Cu则在在中、高温(450~300℃)范围中沉淀。通过利用LMA反演及GEM正演相结合定量化地刻画了玉龙斑岩铜矿水岩反应过程,由此揭示了斑岩矿床蚀变分带是逐渐冷却的单一岩浆热液与斑岩体不断反应的结果,且不同温度窗口对应着钾硅酸盐化(450~360℃)、青磐岩化(360~320℃)和绢英岩化(320~200℃)蚀变矿物的形成,故含矿流体温度的快速下降可能是玉龙铜矿蚀变叠加的重要因素。此外,Cu、Mo络合离子溶解度对温度变化的差异响应,导致了Mo矿化主要发育于靠近斑岩体的高温区域,而Cu则以网脉状-浸染状叠加到Mo矿化之上,并广泛分布于斑岩体周边的高-中温区域。展开更多
Aerosol and snow samples were collected at ablation zone of Baishui (白水) Glacier No. 1, Mt. Yulong (玉龙), from May to June, 2006. The concentrations of Cl^-, NO3^-, SO4^2-, Na^+, K^+, Mg^2+, and Ca^2+ were ...Aerosol and snow samples were collected at ablation zone of Baishui (白水) Glacier No. 1, Mt. Yulong (玉龙), from May to June, 2006. The concentrations of Cl^-, NO3^-, SO4^2-, Na^+, K^+, Mg^2+, and Ca^2+ were determined by ion chromatograph both in aerosol and snow samples. The average total aerosol loading is 25.45 neq.scm^-1, NO3^- and Na^+ are the dominant soluble ions in the aerosol, accounting for 39% and 21% of average total aerosol loading, respectively. Monsoon circulation reduces the concentration of most ions, indicating that wet scavenging is effective for aerosol particles. In snow samples, SO4^2- and Ca^2+ are the dominant anion and cation, respectively. A lower Na^+/Cl^- ratio was found in fresh snow samples compared to the higher ratio that was found in aerosol samples. Analyzing the difference in SO4^2- and NO3^- in air and fresh snow indicated that the aerosol was influenced by local circulation, but the components in fresh snow samples were from long-distance transport. Enrichment of NO3^- in aerosol samples is attributed to motor exhaust emissions from tourism by calculating the SO4^2-/NO3^- ratio in aerosol and fresh snow samples. The temporal variation and correlation coefficients between soluble species in aerosol samples suggest that Cl^-, Na^+ and K^+ come from sea-salt aerosol, and SO4^2-, Mg^2+ and Ca^2+ are from continental crust sources.展开更多
A paleosol dated for about 500-700 kaBP and developed on a glacial deposit at -3 000 in a.s.l. in the Yulong Mountains is studied using soil chemical, morphological and mineralogical methods. The analytical results in...A paleosol dated for about 500-700 kaBP and developed on a glacial deposit at -3 000 in a.s.l. in the Yulong Mountains is studied using soil chemical, morphological and mineralogical methods. The analytical results indicate that this soil was formed under tropical and humid conditions and can be classified as red soil, which cannot be formed in the present alpine environment at the studied site. This implies that the southeast margin of the Tibetan Plateau has experienced intense uplift since the formation of the paleosol. According to the necessary conditions for the formation of the modern red soil in China, we estimate that the展开更多
The regional geologic and geomorphic observations show that an active arcuate normal fault constitutes the main boundary fault of the Haba-Yulong Snow Mountains (HYSM). This fault is called eastern piedmont fault of H...The regional geologic and geomorphic observations show that an active arcuate normal fault constitutes the main boundary fault of the Haba-Yulong Snow Mountains (HYSM). This fault is called eastern piedmont fault of Haba-Yulong Snow Mountains (HYPF). The fault consists of two segments with differential trend; the northern segment is NW-trending and NE-dipping and the southern section is S-N trending and E-dipping. Three sets of fault scarps cutting late Quaternary landforms and their dating results indicate that the fault is a prominent Holocene active fault and its throw rates are 0.3―1.4 mm/a during late Quaternary. The geometry and kinematics of the fault suggest that the arcuate normal faulting or rifting are typical surface deformation pattern at the two tips of the Z-shaped rift zone of northwestern Yunnan, which is related to regional east-west extension accompanying clockwise rota- tion of micro-block.展开更多
The seasonal and inter-annual variations of pH and EC (electrical conductivity) at Yulong (玉龙) Snow Mountain, Lijiang (丽江) City, are sensitive to precipitation variations and are important indicators of the ...The seasonal and inter-annual variations of pH and EC (electrical conductivity) at Yulong (玉龙) Snow Mountain, Lijiang (丽江) City, are sensitive to precipitation variations and are important indicators of the atmospheric environment. The pH of summer rainfall at Lijiang City ranges from 6.7 to 7.4, and alkaline mineral salts dominate the variations of rainfall acidity, pH values in the shallow firn profile at Baishui (白水) Glacier No. 1 range from 5.6 to 6.3, and EC values from 2.4 to 7.3 μs/cm. The ranges are lower than those in other firn cores from China because of stronger elution and the influence of marine aerosols. This indicates that environmental records from a monsoonal temperate glacier differ from those at continental glaciers.展开更多
基金jointly supported by the National Key Research and Development Program of China(Grant No.2022YFC2905001)the Basic Research Fund of the Chinese Academy of Geological Sciences(Grant No.JKYZD202316)+2 种基金the National Natural Science Foundation of China(Grant Nos.42272093,42230813,42002097)the Research Project of the Shengyuan Mining Co.,Ltd.,Tibet(Grant No.XZSYKYJT-JSFW2019-001)the China Scholarship Council project and the Geological Survey project(Grant Nos.DD20230054,DD20221684,DD20221690,DD20230031,DD20230049,DD20230338)。
文摘Multistage tungsten mineralization was recently discovered in the Mamupu copper-polymetallic deposit in the southern Yulong porphyry copper belt(YPCB),Tibet.This study reports the results of cathodoluminescence,trace element and Sr isotope analyses of Mamupu scheelite samples,undertaken in order to better constrain the mechanism of W mineralization and the sources of the ore-forming fluids.Three different types of scheelite are identified in the Mamupu deposit:scheelite A(Sch A)mainly occurs in breccias during the prograde stage,scheelite B(Sch B)forms in the chlorite-epidote alteration zone in the retrograde stage,while scheelite C(Sch C)occurs in distal quartz sulfide veins.The extremely high Mo content and negative Eu anomaly in Sch A represent high oxygen fugacity in the prograde stage.Compared with ore-related porphyries,Sch A has a similar REE pattern,but with higher ΣREE,more depleted HREE and slightly lower(^(87)Sr/^(86)Sr)i ratios.These features suggest that Sch A is genetically related to ore-related porphyries,but extensive interaction with carbonate surrounding rocks affects the final REE and Sr isotopic composition.Sch B shows dark(Sch B-I)and light(Sch B-II)domains under CL imaging.From Sch B-I to Sch B-II,LREEs are gradually depleted,with MREEs being gradually enriched.Sch C has the highest LREE/HREE ratio,which indicates that it inherited the geochemical characteristics of fluids after the precipitation of HREE-rich minerals,such as diopside and garnet,in the early prograde stage.The Mo content in Sch B and Sch C gradually decreased,indicating that the oxygen fugacity of the fluids changed from oxidative in the early stages to reductive in the later,the turbulent Eu anomaly in Sch B and Sch C indicating that the Eu anomaly in the Mamupu scheelite is not solely controlled by oxygen fugacity.The extensive interaction of magmatic-hydrothermal fluids and carbonate provides the necessary Ca^(2+)for the precipitation of scheelite in the Mamupu deposit.
基金supported by the National Natural Science Foundation of China (Grant No.41690143)the Fund from the State Key Laboratory of Cryospheric Sciences,Chinese Academy of Sciences (Grant No.SKLCS-OP-201602)the Fundamental Research Funds for the Central Universities from Nanjing Agricultural University,China (Grant No.SK2016033)
文摘Glaciers, with their unique and spectacular appearances and rich and varied terrain, have received widespread attention and become important tourist attractions. This paper uses the travel cost method to estimate the recreational value of the glacier tourism resources of Yulong Snow Mountain(also called Jade Dragon Snow Mountain), which is the most developed glacier tourist attraction in China. First-hand information was obtained through field surveys, and the travel costs of visitors visiting the Yulong Snow Mountain glacier were calculated before the method was applied to evaluate the recreational value of the focal glacier resource. The results show that the Yulong Snow Mountain consumer surplus associated with its glacier resources in 2016 ranged from 645.59-3439.10 million CNY, and the total recreational value ranged from 1.97-8.17 billion CNY. Approaches allocating travel costs across multiple recreational sites, however, can vary, and there is large difference in estimated results depending on used approaches. Nevertheless, the results of the analysis can help understand the socio-economic value of glacier resources and provide a reference for their development and protection.
文摘The glacier on the Yulong Mountain is one of the most important attractions in Lijiang, Yunnan, China. But it keeps retreating these years due to global warming, which is bound to influence regional tourism significantly in Lijiang. This study estimates the effects of the glacier retreat of the Yulong Mountains on tourism there. Primary data were collected through a visitor survey including demographics, motives, lengths of stay, and opinions about each tourism resource from tourists to Lijiang, as well as questions about which scenic spot(s) they had visited or would visit, how much they expended per day during their visit and how their visiting behavior would be changed upon the hypothesis that the glacier would disappear. These data were used to analyze the proportion of the contribution of glacier to the tourism in Lijiang and estimate the impact of glacier on the regional tourism quantitatively. According to the survey, it could be concluded that three quarters of the tourists to Lijiang were interested in the Yulong Mountain glacier, indicating that the glacier possesses notable appeal for sightseeing tourists. The results of our analysis showed that about 689,013-1,508,247 tourists, accounting for 19.63-42.97 % of the total 3,510,000 domestic tourists to Lijiang in 2004, would not come to Lijiang in the absence of the glacier, resulting in a possible direct economic loss of 84,382,508-184,713,011 USD (viz. 700,374,824-1,533,117,993 RMB) and a markedly decrease in the attraction radius.
基金supported by the Research Project of Shengyuan Mining Group Co.Ltd,Tibet(Grant No.XZSYKYJT-JSFW-2019-001)the Basic Research Fund of Institute of mineral Resource,Chinese Academy of Geological Sciences(Grant Nos.KJ2102,KK2116,KK2017)+2 种基金the National Natural Science Foundation of China(Grant No.41902097)the Science and Technology Plan Project of the Tibetan Autonomous Region(Grant No.XZ201901-GB-24)Geological Survey project(Grant No.DD20190167)。
文摘The Mamupu skarn-type Cu-Au polymetallic deposit represents the first discovery of a medium deposit in the southern Yulong porphyry copper belt(YPCB),eastern Tibet.The Cu-Au mineralization mainly occurs as chalcopyrite in breccia,within the plate-like carbonate interlayer,being closely related to chloritization(e.g.,chlorite,magnetite and epidote)and skarnization(e.g.,diopside,tremolite and garnet).The ore-related quartz syenite porphyry(QSP)and granodiorite porphyry(GP)were emplaced at 40.1±0.2 Ma and 39.9±0.3 Ma,respectively.The QSP of Mamupu is an alkaline-rich intrusion,relatively enriched in LREE,LILE,depleted in HFSE,with no significant negative Eu and Ce anomalies,slightly high(^(87)Sr/^(86)Sr)i,lowε_(Nd)(t),uniform(^(206)Pb/^(204)Pb)i andε_(Hf)(t)values,which indicates that the porphyry magma may be caused by both the mixing of metasomatized EM II enriched mantle and thickened juvenile lower crust.The QSP in the Mamupu deposit shares a similar genesis of petrology to other ore-related porphyries within the YPCB.High oxygen fugacity and water content of the magmas are essential for the formation of porphyry and skarn Cu deposits.The QSP has similar high magmatic oxidation states and water content to the Yulong deposit,which indicates that the Mamupu has a high prospecting potential.Differences in the geological characteristics and scale of mineralization between the Mamupu and other YPCB deposits may be due to the different emplacement depths of ore-related intrusions,as well as differences in the surrounding rocks.
基金National Natural Science Foundation of China, No.40501014 No.90511007 Talent Culture Project for Special Subject of Glaciology and Geocryology, No.J0130084
文摘Based on the data of δ^18O in surface snow, snow pits, meltwater and the glacier-fed fiver water at Baishui Glacier No. 1, Mt. Yulong, the isotopic fractionation behaviors in the typical monsoonal temperate glacier system in winter and summer were compared. The results indicate that the isotopic fractionation degree in summer is greater than that in winter, suggesting that the snow/ice melting is more intense in summer. Moreover, whenever it is in winter or summer, from surface snow to meltwater, and to glacier-fed fiver water, the gradient of δ^18O with altitude gradually increases. This shows that the degree of isotopic fractionation gradually strengthens when surface snow is being converted into meltwater and finally into glacial fiver water, which suggests that the influence of post-depositional processes on δ^18O gradient in the monsoonal temperate glacier region differs spatially.
文摘The Yulong supper\|large copper deposit is situated within the well\|known S\|N striking Yulong copper\|molybdenum ore belt. The ore\|bearing biotite\|monogranitic porphyry was emplaced within clastic rocks (mainly shales and siltstones) of the Jiapila Formation (T 3 j ) and carbonate rocks of the Bolila Formation (T 3 b ) of the Upper Triassic. Five mineralization patterns have been recognized in the deposit, i.e., ①veinlet\|disseminated Cu\|Mo ore in the porphyry; ②skarn\|type Cu ore at the contact zone with carbonates (T 3 b ); ③stratiform\|like oxidized Cu ore between T 3 b carbonate rocks and T 3 j hornstones; ④brecciated Cu ore at the local periphery of porphyry; and ⑤vein Pb\|Zn\|Ag ore in the outer contact zone. They constitute a unique integrated polymetal mineralization series of epigenetic intermediate\|acid magmatic hydrothermal system.Studies have shown that the Yulong deposit was the coupling product of sedimentation, magmatism, and tectonism. The Cu\|bearing sandstones in the Japila Formation have provided partial ore\|bearing materials for the porphyry mineralization during the Himalayan period. The mineralized porphyry mass was passively emplaced and controlled by a nose\|like anticlinal trap opening to the north. The interlayered fractured zone formed during folding between the Jiapila and Bolila Formations acted as favorable host space for stratiform\|like skarn and oxidized ores. A large number of cleavages and fissures developed during folding provided both conduits for the circulation of ore\|forming fluids and host spaces for Pb\|Zn\|Ag ore veins. The veinlet\|disseminated Cu\|Mo ore in the porphyry mass owns the characteristics of typical porphyry copper deposits in the world. The veinlet\|disseminated ore body and the stratiform\|like skarn\|type and/or oxidized ore body, the two main ore bodies in Yulong, are connected with each other and shown as “mushroom\|like" shape, in which the former occurs as “mushroom stem" and the latter as “mushroom cover".
文摘The zone of Yulong copper deposit is considered superlarge in scale all over the world, which is a part of Tethys to Himalaya Ore\|forming zone. The geological background of the Jinshajiang and Lancangjiang Faults provided utility for accumulated of copper, molybdenum and so on. The Yulong copper zone is the most important characteristic in the east Qinghai—Xizang Plateau (Tibet), which isabout 400km in length from north to south, and 30~70km in width from east to west. The structural channel for ores accumulation was constructed in Yanshan orogeny and the process of ore forming of the zone was mainly in Himalaya orogeny. The Yulong copper zone can be divided into three subzones, each named as north, south and east subzone which the north subzone is 50km in length of about NNW direction. Based on the geological interpretation (Fig.1), we understood that NW structures are distributed mainly in this area, then EW and NNW, and the sigmoid structures extended reflect their extrusion character. The EW and NNW structures are distributed in small scale and extended stable, which are cut to each other. The NNW structure was interpreted as undercover fracture, which may occurred earlier than NW one. Beside, of the structure, there are some differences in image tone, linear, relief, strata combination, structure pattern and so on. Therefore, the undercover fault played key efforts to Yulong copper formation.
文摘The Yulong and Haba snowcapped ranges in the southeast side of the Qinghai—Xizang (Tibet) Plateau are situated structurally in a corner between the Dianxi Block to the west, the Yangzi Landmass to the southeast and Songpan—Ganzi folded belts to the north. Deformations in this area are strongly effected by the Tethys—Himalaya movement and defined by the Jinshajiang\|Honghe fault in the west and the Xiaojinhe fault in the southeast. A Jinshajiang river cut through in the middle with about 200 meters drop height that gives an exposed cross section.The Yulong—Haba range is an N—S trending anticline (F 3/D 3) comprising a metamorphic core of unknown ages and a sedimentary cover from mid\| Devonian onwards. Contact between the metamorphic core and the cover sequence is structurally. Although there is no evidence being found for the unconformity interface, deformation in the core, dominated by mica\|quartz schists, phyllites and quartzite, and the cover rocks, dominated by marbles, are different. The core rocks underwent a metamorphism with well developed foliations (S 1/D 1) in a greenschist facies condition. Occasionally an intrafolial fold (F 1, folded S 0) present in the S 1 layering. The S1 foliation was re\|folded by recumbent folds (F 2/D 2). Orientations of the axes of F 2 recumbent folds, the crenulation and mineral lineations now are shallowly plunged to S or N with angles less than 20° since the intensity of the D 3 deformation, during which both the core and cover rocks are involved to form the regional upright F 3 fold. All of the L\|S fabrics formed during D 2 in the core rocks are cut off by a set of near E—W or SWW—NEE trending normal faults that showing a top to the SSE extensional movement occurred during the D 3 event as a result of syn\|thickening extension (D 3′). Deformations D 4 are characterized by (1) numbers of near S—N trending high\|angle normal faults, and (2) interlayer gliding in the cover rocks, and lower angle detachment zones in the contact. Movement indicators in the D 4 structures showing a NEE in the east side of the F 3 fold, and a SWW in the west side, normal sense of shear that demonstrated a post\|thickening extension in the area.
文摘During the summers of 1999 and 2000, sampling was carried out in Mt. Yulong, for the investigation of the spatial distribution of oxygen stable isotope in the atmospheric glacial hydro system and similar results obtained in the two years have confirmed our conclusion. There is an evident negative correlation between stable isotopic composition and air temperature precipitation amount, suggesting that there exits a strong 'precipitation amount effect' in this typical monsoon temperate glacier region. There are marked differences between the δ 18 O values in winter accumulated snow, glacial meltwater, summer precipitation and glacier feeding stream. Under the control of varied climatic conditions, spatial and temporal variations of above glacial hydro mediums are apparent. Isotopic depletion or fractionation and ionic changes had occurred during the phase change and transformation processes of snow ice, ice meltwater, flowing of runoff and contact with bedrock. The variation of stable isotope in a runoff can reflect not only its own flowing process but also its different feeding sources.
文摘Extending in a NNW-SSE direction. the Yulong porphyry copper belt is the largest and richest porphyry copper belt in China, originating in the Paleogene. Tectonically located on the eastern margin of the northern Tibet geodepression. and nearly 500 km of the Himalayan Yarlung Zangbo plate subduction zone of nearly E-W trend. it is a relatively typical intracontinental rejuvenated platform-type porphyry copper belt. Ore-bearing porphyry masses in the belt mainly represented by monzogranite-porphyry occurring as stocks in variegated sandshale of the lower Upper Triassic Jiapila Fromation and its overlying and underlying copper-bearing strata. They are characterized by enrichment in K. CI and LREE. abundant fluid inclusions and a distinct porphyroblastic texture. The oxygen. hydrogen. strotium. lead and sulfur isotopic values of the rock show the feature of crust-mantle mixing.The Orebodies are plpe-shaped stratoid; the mineralization is dominated by Cu and Mo, accompanied by Fe. Co. Au. Ag. Bi. W. Pb. Zn. and Pt-group elements. Alteration is strong. marked mainly by potassic alteration, silicification. skarnization and propylitization. The formation of this type of deposit largely progressed through two stages. The first stage was the stage of formation of Cu-bearing source beds. It occurred in the Triassic. when a transgressive copper-bearing formation was deposited on the western margin of the Qamdo Bay. which was represented by intermediate-acid volcanic rocks and variegated sandshale in the lower part. dolomitic carbonate rocks in the middle and black carbonaceous sandshale in the upper part. In the second stage. composite porphyry copper deposits were formed. This stage took place in the Paleogene. when this district was in a stage of platform rejuvenation. forming a series of NNW-trending deep faults. so that Na, K. Cl. H2O and CO2-rich hydrothermal fluids from the depths were injected into the upper crust and replaced and melted copper-bearing sialic rocks of the upper crust. e. g. the Triassic copper-bearing rock series in the Yulong area. to form porphyroblastic cooper-bearing intermediate-acid porphyry.
文摘蚀变分带和成矿机制的准确厘定是建立斑岩成矿模型与找矿预测的关键。本文以新生代金沙江-哀牢山成矿带的玉龙斑岩铜矿为例,通过质量作用定律(LMA)和吉布斯自由能最小化模型(GEM),构建含矿热液与斑岩侵入体的pH-f O 2相图和动态传输模型,以揭示蚀变分带成因和金属成矿机制。LMA与GEM结果显示初始成矿流体pH值为4.7,logf_(O2)=-23.0(ΔFMQ=+2.7),且溶解Cu含量为1138×10^(-6),Mo为1.2×10^(-6)。研究表明,当该酸性及强氧化性流体流入二长花岗斑岩体时,在温度为450~360℃范围内,代表钾硅酸盐化蚀变的钾长石、黑云母、硬石膏、赤铁矿和磁铁矿的矿物逐渐沉淀,且与钾硅酸盐化蚀变相关流体具有较高pH值(5.0~7.0)和氧逸度(ΔFMQ=+2.9~+3.6)特征;当温度在360~320℃范围时,代表青磐岩化蚀变阶段的典型矿物如绿帘石、铁绿泥石和斜绿泥石等逐渐形成,流体pH值(5.0~6.4)和氧逸度(ΔFMQ=+1.1)均有所下降;当温度进一步从320℃下降到200℃时,流体pH值(5.0~5.7)进一步小幅下降,而氧逸度则(ΔFMQ=+1.7)略有回升,在此期间,绢云母和方解石等开始沉淀并形成典型的绢英岩化蚀变。此外,以HMoO_(4)^(-)和MoO_(4)^(2-)为载体的Mo在狭窄高温区间(450~370℃)内沉淀,而以CuCl(CuCl_(4)^(3-)、CuCl_(2)^(-)、CuCl)为主要载体的Cu则在在中、高温(450~300℃)范围中沉淀。通过利用LMA反演及GEM正演相结合定量化地刻画了玉龙斑岩铜矿水岩反应过程,由此揭示了斑岩矿床蚀变分带是逐渐冷却的单一岩浆热液与斑岩体不断反应的结果,且不同温度窗口对应着钾硅酸盐化(450~360℃)、青磐岩化(360~320℃)和绢英岩化(320~200℃)蚀变矿物的形成,故含矿流体温度的快速下降可能是玉龙铜矿蚀变叠加的重要因素。此外,Cu、Mo络合离子溶解度对温度变化的差异响应,导致了Mo矿化主要发育于靠近斑岩体的高温区域,而Cu则以网脉状-浸染状叠加到Mo矿化之上,并广泛分布于斑岩体周边的高-中温区域。
基金supported by the National Natural Science Foundation of China (Nos.40801028,40971019)the National Basic Research Program of China (No.2007CB411501)+1 种基金the West Light Foundation of Chinese Academy of Sciences (No.O828A11001)the Funds from the State Key Laboratory of Cryospheric Sciences and the Lijiang City Government
文摘Aerosol and snow samples were collected at ablation zone of Baishui (白水) Glacier No. 1, Mt. Yulong (玉龙), from May to June, 2006. The concentrations of Cl^-, NO3^-, SO4^2-, Na^+, K^+, Mg^2+, and Ca^2+ were determined by ion chromatograph both in aerosol and snow samples. The average total aerosol loading is 25.45 neq.scm^-1, NO3^- and Na^+ are the dominant soluble ions in the aerosol, accounting for 39% and 21% of average total aerosol loading, respectively. Monsoon circulation reduces the concentration of most ions, indicating that wet scavenging is effective for aerosol particles. In snow samples, SO4^2- and Ca^2+ are the dominant anion and cation, respectively. A lower Na^+/Cl^- ratio was found in fresh snow samples compared to the higher ratio that was found in aerosol samples. Analyzing the difference in SO4^2- and NO3^- in air and fresh snow indicated that the aerosol was influenced by local circulation, but the components in fresh snow samples were from long-distance transport. Enrichment of NO3^- in aerosol samples is attributed to motor exhaust emissions from tourism by calculating the SO4^2-/NO3^- ratio in aerosol and fresh snow samples. The temporal variation and correlation coefficients between soluble species in aerosol samples suggest that Cl^-, Na^+ and K^+ come from sea-salt aerosol, and SO4^2-, Mg^2+ and Ca^2+ are from continental crust sources.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 49894170-06 and 49725206) and the National Key Project for Basic Research on the Tibetan Plateau (Grant No. G199804800).
文摘A paleosol dated for about 500-700 kaBP and developed on a glacial deposit at -3 000 in a.s.l. in the Yulong Mountains is studied using soil chemical, morphological and mineralogical methods. The analytical results indicate that this soil was formed under tropical and humid conditions and can be classified as red soil, which cannot be formed in the present alpine environment at the studied site. This implies that the southeast margin of the Tibetan Plateau has experienced intense uplift since the formation of the paleosol. According to the necessary conditions for the formation of the modern red soil in China, we estimate that the
基金Supported by Department of International Cooperation of Ministry of Science and Technology of China (Grant No. 2006DFA21320)China Geological Survey of Ministry of Land and Resources (Grant No. 1212010541404)National Natural Science Foundation of China (Grant No. 40501006)
文摘The regional geologic and geomorphic observations show that an active arcuate normal fault constitutes the main boundary fault of the Haba-Yulong Snow Mountains (HYSM). This fault is called eastern piedmont fault of Haba-Yulong Snow Mountains (HYPF). The fault consists of two segments with differential trend; the northern segment is NW-trending and NE-dipping and the southern section is S-N trending and E-dipping. Three sets of fault scarps cutting late Quaternary landforms and their dating results indicate that the fault is a prominent Holocene active fault and its throw rates are 0.3―1.4 mm/a during late Quaternary. The geometry and kinematics of the fault suggest that the arcuate normal faulting or rifting are typical surface deformation pattern at the two tips of the Z-shaped rift zone of northwestern Yunnan, which is related to regional east-west extension accompanying clockwise rota- tion of micro-block.
基金supported by the National Basic Research Program of China (No.2007CB411501)the National Natural Science Foundation of China (Nos.40971019,J0630966,90511007)+2 种基金the Special Grant for Postgraduate Research,Innovation and Practicethe West Light Foundation of Chinese Academy of Sciences (No.O828A11001)the Fund from State Key Laboratory of Cryospheric Sciences
文摘The seasonal and inter-annual variations of pH and EC (electrical conductivity) at Yulong (玉龙) Snow Mountain, Lijiang (丽江) City, are sensitive to precipitation variations and are important indicators of the atmospheric environment. The pH of summer rainfall at Lijiang City ranges from 6.7 to 7.4, and alkaline mineral salts dominate the variations of rainfall acidity, pH values in the shallow firn profile at Baishui (白水) Glacier No. 1 range from 5.6 to 6.3, and EC values from 2.4 to 7.3 μs/cm. The ranges are lower than those in other firn cores from China because of stronger elution and the influence of marine aerosols. This indicates that environmental records from a monsoonal temperate glacier differ from those at continental glaciers.