Carbon(C)sequestered in the mantle andcrust over geological timescales accounts for more than 99% of allcarbon in the bulk silicate Earth and plays a fundamental role in driving surface biogeochemical cycles,which inv...Carbon(C)sequestered in the mantle andcrust over geological timescales accounts for more than 99% of allcarbon in the bulk silicate Earth and plays a fundamental role in driving surface biogeochemical cycles,which involve only a tiny fraction of Earth's total carbon inventory[1].In addition to CO_(2) released through near surface weathering of sedimentary rocks[2],a substantial,butstill poorly quantified,amount of carbon in the deeper crust and mantle(hereafter referred to as deeply-sourced carbon)could be mobilized by magmatism and metamorphism and then outgassed in volcanic and non-volcanic settings.展开更多
Knowledge of the seismogenic environment of fault zones is critical for understanding the processes and mechanisms of large earthquakes.We conducted a rock magnetic study of the fault rocks and protoliths to investiga...Knowledge of the seismogenic environment of fault zones is critical for understanding the processes and mechanisms of large earthquakes.We conducted a rock magnetic study of the fault rocks and protoliths to investigate the seismogenic environment of earthquakes in the Motuo fault zone,in the eastern Himalayan syntaxis.The results indicate that magnetite is the principal magnetic carrier in the fault rocks and protolith,while the protolith has a higher content of paramagnetic minerals than the fault rocks.The fault rocks are characterized by a high magnetic susceptibility relative to the protolith in the Motuo fault zone.This is likely due to the thermal alteration of paramagnetic minerals to magnetite caused by coseismic frictional heating with concomitant hydrothermal fluid circulation.The high magnetic susceptibility of the fault rocks and neoformed magnetite indicate that large earthquakes with frictional heating temperatures>500℃have occurred in the Motuo fault zone in the past,and that the fault maintained an oxidizing environment with weak fluid action during these earthquakes.Our results reveal the seismogenic environment of the Motuo fault zone,and they are potentially important for the evaluation of the regional stability in the eastern Himalayan syntaxis.展开更多
Frequent glacier-related watershed geohazard chains are causing severe damage to life and infrastructure,reported consistently from the Eastern Himalayan Syntaxis.This paper presents a systematic method for researchin...Frequent glacier-related watershed geohazard chains are causing severe damage to life and infrastructure,reported consistently from the Eastern Himalayan Syntaxis.This paper presents a systematic method for researching geohazard,from regional to individual scale.The methodology includes the establishment of geological chain inventories,discrimination of geohazard chain modes,analyses of dynamics and dam breaches,and risk assessments.The following results were obtained:(1)In the downstream of Yarlung Zangbo River,175 sites were identified as high-risk for river blockage disasters,indicating the development of watershed geohazards.Five geohazard chain modes were summarized by incorporating geomorphological characteristics,historical events,landslide zoning,and materials.The risk areas of typical hazard were identified and assessed using InSAR data.(2)Glacier-related watershed geohazard chains are significantly different from traditional landslides.A detailed inversion analysis was conducted on the massive rock-ice avalanche in the Sedongpu gully in 2021.This particular event lasted roughly 300 seconds,with a maximum flow velocity of 77.2 m/s and a maximum flow height of 93 meters.By scrutinizing the dynamic processes and mechanical characteristics,mobility stages and phase transitions can be divided into four stages.(3)Watershed geohazard chains tend to block rivers.The peak breach discharge of the Yigong Landslide reached 12.4×10^(4) m^(3)/s,which is 36 times the volume of the seasonal flood discharge in the Yigong River.Megafloods caused by landslide dam breaches have significantly shaped the geomorphology.This study offers insights into disaster patterns and the multistaged movement characteristics of glacier-related watershed geohazard chains,providing a comprehensive method for investigations and assessments in glacial regions.展开更多
The Gabo lithium deposit represents a newly discovered pegmatite-type lithium deposit within the Himalayan metallogenic belt.The tourmaline-muscovite granite,the largest leucogranite in the mining area,displays a clos...The Gabo lithium deposit represents a newly discovered pegmatite-type lithium deposit within the Himalayan metallogenic belt.The tourmaline-muscovite granite,the largest leucogranite in the mining area,displays a close spatial correlation with the Li-pegmatite veins.This study aims to examine the genesis of tourmaline and evaluate the significance and potential of pegmatite lithium deposits.Tourmaline is extensively distributed in tourmaline-muscovite granite at Gabo deposit in Luozha county(Xizang).Investigation of the compositional and in situ boron isotopes of the tourmaline revealed that the tourmalines mainly belong to the schorl group and exhibit uniform elevated Li-Sn contents andδ^(11)B values(-11.6‰to-10.5‰).This indicates that the tourmaline mainly crystallized from a boron-rich granitic magma undergoing enrichment in elemental lithium during the tourmaline crystallization process.Compared with the principal rare metal leucogranite-pegmatites in the Himalayan orogen,it is proposed that the elevated lithium(Li)content of tourmaline serves as an eff ective mineral indicator for the highly evolved pegmatite-type rare metal deposits.展开更多
1 Himalayan salt,a pink organic variety of the essential food sourced from Pakistan,is becoming increasingly popular in China,fueled by growing demand from quality‑conscious consumers.Himalayan salt is on the dining t...1 Himalayan salt,a pink organic variety of the essential food sourced from Pakistan,is becoming increasingly popular in China,fueled by growing demand from quality‑conscious consumers.Himalayan salt is on the dining tables of more Chinese consumers on occasions such as camping,barbecue parties and grilling steak at home,and it has been used to improve taste and for decorative purposes.展开更多
The Himalayan Griffon(Gyps himalayensis), occurring mainly in the Tibetan Plateau, is one of the scavengers of Old World vultures. As of now, knowledge about the Himalayan Griffon in China remains scarce. Estimates of...The Himalayan Griffon(Gyps himalayensis), occurring mainly in the Tibetan Plateau, is one of the scavengers of Old World vultures. As of now, knowledge about the Himalayan Griffon in China remains scarce. Estimates of its number, habitat, and conservation status were carried out in 2003, 2009 and 2102 in the Lhasa River Valley, where we paid particular attention to the population living at the Drigung Thel Monastery, Mzizhokunggar County. The resident species occupies alpine meadows in the daytime and roosts at the upper parts of cliffs at night between 4400–5000 m elevation. The number of individual birds of the Himalayan Griffon around the monastery was estimated as 230 in 2003, 250 in 2009 and 200 in 2012. This population is considered relatively stable, thanks to the current conservation measures by Buddhist monks and local people. Given the lack of any baseline information, it is difficult for us to recommend and provide any effective conservation measures.展开更多
The Himalayan Monal (Lophophorus impejanus) is a national first grade protected species in China.So far,current knowledge of the Himalayan Monal in China is still poor.An estimate of its distribution,numbers and habit...The Himalayan Monal (Lophophorus impejanus) is a national first grade protected species in China.So far,current knowledge of the Himalayan Monal in China is still poor.An estimate of its distribution,numbers and habitat was conducted during a two-year investigation from 2008 to 2009 in southern Tibet,especially in Lhozhag,Cona and Yadong counties.In total,12 sightings of the Himalayan Monal were recorded during the study period.Our data suggest that this bird is mainly found in Medog,Zayu,Cona,Lhunze,Lhozhag,Nyalam,Dingjie,Gamba and Yadong counties on the southern slopes of the Himalayas.Its western-most location was confirmed to be Nyalam County.The bird ranges in elevation from 3800 to 4300 m in the summer and from 3200 to 3500 m in the winter.We sighted 36-37 individual birds,consisting of 8-10 males,16-20 females and 7-8 sub-adults inhabiting the area around the Kajiu Monastery in Lhozhag County.The birds are mainly found in rocky forests,interspersed with steep slopes,cliffs and alpine meadows at elevations between 3800 and 4000 m.The population density of the Himalayan Monal near the Kajiu Monastery is 2.03 individual birds per km2,much larger than that of Yadong and Cona counties (0.052 individuals per krn2).展开更多
Located in southern Ningxia Hui Autonomous Region,northwest China,the Liupan Mountain National Nature Reserve covers a total area of 26,783.64 hectares.Established in 1982 and upgraded to national status in 1988,it pr...Located in southern Ningxia Hui Autonomous Region,northwest China,the Liupan Mountain National Nature Reserve covers a total area of 26,783.64 hectares.Established in 1982 and upgraded to national status in 1988,it protects a vital temperate mountainous forest ecosystem on the Loess Plateau.The reserve is centred around the Liupan Mountain range,one of China’s youngest mountain chains,formed by Himalayan tectonic movements.展开更多
The eastern Himalayan syntaxis in Namjagbarwa is a high-grade metamorphicterrain formed by the India-Eurasia collision and northward indentation of the Indian continent intoAsia. Right- and left-lateral slip zones wer...The eastern Himalayan syntaxis in Namjagbarwa is a high-grade metamorphicterrain formed by the India-Eurasia collision and northward indentation of the Indian continent intoAsia. Right- and left-lateral slip zones were formed by the indentation on the eastern and westernboundaries of the syntaxis respectively. The Dongjug-Mainling fault zone is the main shear zone onthe western boundary. This fault zone is a left-lateral slip belt with a large component ofthrusting. The kinematics of the fault is consistent with the shortening within the syntaxis, andthe slipping history along it represents the indenting process of the syntaxis. The Ar-Archronological study shows that the age of the early deformation in the Dongjug-Mainling fault zoneranges from 62 to 59 Ma. This evidences that the India-Eurasia collision occurred in the earlyPaleocene in the eastern Himalayan syntaxis.展开更多
The western boundary of the Eastern Himalayan Syntaxis (EHS) is a deformation belt up to 30km wide (Fig.1). Trending ca. N35°E, it separates the Gangdise magmatic belt in the west from the gneiss of EHS in the ea...The western boundary of the Eastern Himalayan Syntaxis (EHS) is a deformation belt up to 30km wide (Fig.1). Trending ca. N35°E, it separates the Gangdise magmatic belt in the west from the gneiss of EHS in the east. Its rock association, mica\|schist, quartzite, marble, and amphibolite, can be traced to the south to Gangdise belt and they were probably metamorphosed from the sediments along Yarlung Zangbo. This belt consists of several intensive deformation zones, the largest one of which is along the belt’s western margin from Dongjug to Mainling and we called this ca. 10km wide shear zone as the Dongjug\|Mainling shear zone (DMSZ).DMSZ experienced earlier ductile shear and later ductile\|brittle normal faulting. The earlier deformation produced mylonitic rocks. Their foliation trends N30°～40°E and dips northwest with the angle ranging from 55°to 80°, steepening northeastward. The penetrative kinematic lineation in the rocks has a varying attitude along the trend of DMSZ. It dips southwest with an angle of ca.35° in the southwest near Mainling, whereas dips northeast in the northeast. Moreover, the northeast dipping lineation steepens northeastwards, e.g., its angle ranges form 30° to 45° in the segment from Serkyim La to Dongjug but becomes 60～70° in the northeast most in another zone near Parlung. Kinematic indicators show that the motion of DMSZ had a left\|lateral slipping component, but the vertical motion components were different in the southwest from the northeast. From Serkyim La to the northeast, DMSZ had a kinematics of NW plate (Gangdise belt) thrusting over the SE plate (EHS) and its thrusting component increased toward northeast. However, the DMSZ has a vertical motion with the SE plate (EHS) as the uplifting plate.展开更多
The eastern Himalayan syntaxis is one of the most tectonically active and earthquake-prone regions on Earth where earthquake-induced geological disasters occur frequently and caused great damages. With the planning an...The eastern Himalayan syntaxis is one of the most tectonically active and earthquake-prone regions on Earth where earthquake-induced geological disasters occur frequently and caused great damages. With the planning and construction of Sichuan-Tibet highway, Sichuan-Tibet railway and hydropower development on the Yarlung Zangbo River etc. in recent years, it is very important to evaluate the seismic landslide hazard of this region. In this paper, a seismic landslide hazard map is produced based on seismic geological background analysis and field investigation using Newmark method with 10% PGA exceedance probabilities in future 50 years by considering the influence of river erosion, active faults and seismic amplification for the first time. The results show that the areas prone to seismic landslides are distributed on steep slopes along the drainages and the glacier horns as well as ridges on the mountains. The seismic landslide hazard map produced in this study not only predicts the most prone seismic landslide areas in the future 50 years but also provides a reference for mitigation strategies to reduce the exposure of the new building and planning projects to seismic landslides.展开更多
The seismotectonic characteristics of ten repeated earthquake swarm sequence within a seismic cluster along Jiali Fault in eastern Himalayan Syntaxis(EHS) have been analysed.The swarms are spatially disposed in and ar...The seismotectonic characteristics of ten repeated earthquake swarm sequence within a seismic cluster along Jiali Fault in eastern Himalayan Syntaxis(EHS) have been analysed.The swarms are spatially disposed in and around Yigong Lake(a natural lake formed by blocking of Yigong River by landslide) and are characterized by low magnitude,crustal events with low to moderate b values.Ms:mb discriminant functions though indicate anomalous nature of the earthquakes within swarm but are considered as natural events that occurred under condition of high apparent stress and stress gradients.Composite fault plane solutions of selected swarms indicate strike-slip sense of shear on fault planes;solution parameters show low plunging compression and tensional axes along NW-SE and NE-SW respectively with causative fault plane oriented ENE-WSW.dipping steeply towards south or north.The fault plane is in excellent agreement with the disposition and tectonic movement registered by right lateral Jiali Fault.The process of pore pressure perturbation and resultant ’r—t plot’ with modelled diffusivity(D = 0.12 m^2/s) relates the diffusion of pore pressure to seismic sequence in a fractured poro-elastic fluid saturated medium at average crustal depth of 15-20 km.The low diffusivity depicts a highly fractured interconnected medium that is generated due to high stress activity near the eastern syntaxial bent of Himalaya.It is proposed that hydro fracturing with respect to periodic pore pressure variations is responsible for generation of swarms in the region.The fluid pressure generated due to shearing and infiltrations of surface water within dilated seismogenic fault(Jiali Fault) are causative factors.展开更多
Background： The fragile landscapes of the Himalayan region are highly susceptible to natural hazards, and there is ongoing concern about current and potential climate change impacts. This study provides background in...Background： The fragile landscapes of the Himalayan region are highly susceptible to natural hazards, and there is ongoing concern about current and potential climate change impacts. This study provides background information on India＇s Western Himalayas and reviews evidence of warming as well as variability in precipitation and extreme events.Methods： Understanding and anticipating the impacts of climate change on Himalayan forest ecosystems and the services they provide to people are critical. Efforts to develop and implement effective policies and management strategies for climate change mitigation and adaptation requires particular new research initiatives. The various studies initiated and conducted in the region are compiled here.Results： Several new initiatives taken by the Himalayan Forest Research Institute in Shimla are described. This includes new permanent observational field studies, some with mapped trees, in high altitude transitional zones for continuous monitoring of vegetation response. We have also presented new strategies for mitigating potential climate change effects in Himalayan forest ecosystems.Conclusions： Assessment of the ecological and genetic diversity of the Himalayan conifers is required to evaluate potential responses to changing climatic conditions. Conservation strategies for the important temperate medicinal plants need to be developed. The impact of climate change on insects and pathogens in the Himalayas also need to be assessed. Coordinated efforts are necessary to develop effective strategies for adaptation and mitigation.展开更多
Water content in nominally anhydrous minerals （NAMs） of the high-pressure （HP） metamorphic rocks controls the thermal structure, rheology and partial melting of orogenic belts. This paper conducts a systematic ana...Water content in nominally anhydrous minerals （NAMs） of the high-pressure （HP） metamorphic rocks controls the thermal structure, rheology and partial melting of orogenic belts. This paper conducts a systematic analysis of water in NAMs of the HP granulites from the Greater Himalayan Sequence （GHS）, representing the thickened lower crust of the eastern Himalayan Orogen. The present result shows that the garnet, clinopyroxene, feldspar, quartz and kyanite contain 188 ppm-432 ppm, 193 ppm-547 ppm, 335 ppm-1 053 ppm, 125 ppm-185 ppm and 89 ppm H2O, respectively, and indicates that the thickened lower crust of the Himalayan Orogen is relatively wet rather than dry. The considerable concentrations of water in the HP granulites are expected to promote the rheological weakening of the metamorphic core of the Himalayan Orogen, providing a favorable evidence for the channel flow model of the exhumation of thickened lower crust.展开更多
In this paper, we analyzed the long-term changes in temperature and precipitation in the Hindu Kush Himalayan (HKH) region based on climate datasets LSAT-V1.1 and CGP1.0 recently developed by the China Meteorological ...In this paper, we analyzed the long-term changes in temperature and precipitation in the Hindu Kush Himalayan (HKH) region based on climate datasets LSAT-V1.1 and CGP1.0 recently developed by the China Meteorological Administration. The analysis results show that during 1901e2014 the annual mean surface air temperature over the whole HKH has undergone a significant increasing trend. We determined the change rates in the mean temperature, mean maximum temperature, and mean minimum temperature to be 0.104 C per decade, 0.077 C per decade, and 0.176 C per decade, respectively. Most parts of the HKH have experienced a warming trend, with the largest increase occurring on the Tibetan Plateau (TP) and south of Pakistan. The trend of precipitation for the whole HKH is characterized by a slight decrease during 1901e2014. During 1961e2013, however, the trend of the annual precipitation shows a statistically significant increase, with a rate of 5.28% per decade and has a more rapid increase since the mid-1980s. Most parts of northern India and the northern TP have experienced a strong increase in the number of precipitation days (daily rainfall 1 mm), whereas Southwest China and Myanmar have experienced a declining trend in precipitation days. Compared to the trends in precipitation days, the spatial pattern of trends in the precipitation intensity seems to be more closely related to the terrain, and the higher altitude areas have shown more significant upward trends in precipitation intensity during 1961e2013.展开更多
In the Indian Himalayan Region, th studies focused on diversity of the plants used fo treating liver diseases/ailments have not been carried out so far. Therefore, the present attempt has been made to study the divers...In the Indian Himalayan Region, th studies focused on diversity of the plants used fo treating liver diseases/ailments have not been carried out so far. Therefore, the present attempt has been made to study the diversity, distribution pattern and conservation status of the plant species used fo treating liver diseases/ailments in that region. A tota of 138 species (35 species of trees, 22 shrubs and 8 herbs) belonging to 98 genera in 60 families hav been recorded. Amongst the families, Euphorbiacea (9 species), and altitudinal zone <1,800 m, (i.e., 11 species) are rich in species. Traditionally, variou plant parts, such as roots/rhizomes/tubers (46 species), leaves (31), whole plants (30), barks (15) fruits (13), seeds and unspecified parts (8 each), and inflorescence (1) are used for the treatment of live diseases/ailments. 34 species are native, 3 ar endemic and 15 near endemic. 7 species ar categorized as Critically Endangered (Betula utilis) Endangered (Podophyllum hexandrum, Ephedra gerardiana, and Nardostachys grandiflora) and Vulnerable (Bergenia ligulata, B. stracheyi, and Hedychium spicatum) using new IUCN criteria Available chemical composition of plant parts used fo the treatment of liver diseases/ailments have beengiven. Assessment of the populations of threatened species, development of an appropriate strategy, action plan for the conservation and sustainable utilization of such components of plant diversity are suggested.展开更多
During the last 40Ma the marine 87 Sr/ 86 Sr record shows a rapid rise (from 0 7078 to 0 7092) [1] , a trend which has been linked to the Himalayan Orogeny [2] . Indeed, many Himalayan rivers, principally those of the...During the last 40Ma the marine 87 Sr/ 86 Sr record shows a rapid rise (from 0 7078 to 0 7092) [1] , a trend which has been linked to the Himalayan Orogeny [2] . Indeed, many Himalayan rivers, principally those of the Ganges\|Brahmaputra system, display high 87 Sr/ 86 Sr relative to [Sr] [3] . Theories concerning the cause of this radiogenic Sr enrichment are diverse, but our results suggest that Lesser Himalayan carbonate\|rich lithologies play a vital role [4,5] .The Bhote Kosi originates in Tibet at ca.5km elevation from Tibetan Sedimentary Series (TSS) bedrock, before traversing the High Himalayan Crystalline Series (HHCS) and Lesser Himalaya (LH) of eastern Nepal, joining the Indrawati (at ca.0 6km elevation) to form the Sun Kosi, part of the Ganges system. Carbonates, calc\|silicates and silicates have been identified from the TSS, HHCS and LH, and the Bhote Kosi provides an opportunity to study the influence of these upon fluvial chemistry. Interest is focused on the cause of a rapid rise in riverine Sr\|isotope ratios immediately downstream of the Main Central Thrust (MCT) and the role of carbonate\|rich lithologies exposed in this section. Similar lithologies are lacking in the catchment of a second Nepalese river system, the Lantang Khola—Trisuli, sampled during the same period, and used as a baseline indicator for the effect of LH carbonates on the dissolved load of the Bhote Kosi.展开更多
The genus Rhododendron of Indian Himalayan Region (IHR) has been enumerated in the present paper. A total of 87 species, 12 subspecies and 8 varieties of Rhododendrons recorded in IHR, among these 6 species and one su...The genus Rhododendron of Indian Himalayan Region (IHR) has been enumerated in the present paper. A total of 87 species, 12 subspecies and 8 varieties of Rhododendrons recorded in IHR, among these 6 species and one subspecies are reported from Western Himalaya. The maximum concentration of 86% observed in Arunachal Pradesh (75 species). The species of Rhododendrons exhibit significant diversity in habit and broad range of distribution from the altitude of 800-6000 m. and the best range is observed in 3001-3500 m altitudes. In analysis revealed 20 taxa are endemic, 30 are rare, 24 are threatened / endangered, 3 are vulnerable and 47 taxa have to be assessed. The major threats to rhododendrons are deforestation and unsustainable extraction for firewood and incense by local people has been discussed.展开更多
基金supported by the National Key Research and Development Program of China(2020YFA0607700)the National Natural Science Foundation of China(41930642 and 42522211).
文摘Carbon(C)sequestered in the mantle andcrust over geological timescales accounts for more than 99% of allcarbon in the bulk silicate Earth and plays a fundamental role in driving surface biogeochemical cycles,which involve only a tiny fraction of Earth's total carbon inventory[1].In addition to CO_(2) released through near surface weathering of sedimentary rocks[2],a substantial,butstill poorly quantified,amount of carbon in the deeper crust and mantle(hereafter referred to as deeply-sourced carbon)could be mobilized by magmatism and metamorphism and then outgassed in volcanic and non-volcanic settings.
基金supported by the Fundamental Research Funds of the Institute of Geomechanics(DZLXJK202401)the National Natural Science Foundation of China(42177172,U2244226,42172255)+1 种基金the China Geological Survey Project(DD20230538)Deep Earth Probe and Mineral Resources ExplorationNational Science and Technology Major Project(2024ZD1000500)。
文摘Knowledge of the seismogenic environment of fault zones is critical for understanding the processes and mechanisms of large earthquakes.We conducted a rock magnetic study of the fault rocks and protoliths to investigate the seismogenic environment of earthquakes in the Motuo fault zone,in the eastern Himalayan syntaxis.The results indicate that magnetite is the principal magnetic carrier in the fault rocks and protolith,while the protolith has a higher content of paramagnetic minerals than the fault rocks.The fault rocks are characterized by a high magnetic susceptibility relative to the protolith in the Motuo fault zone.This is likely due to the thermal alteration of paramagnetic minerals to magnetite caused by coseismic frictional heating with concomitant hydrothermal fluid circulation.The high magnetic susceptibility of the fault rocks and neoformed magnetite indicate that large earthquakes with frictional heating temperatures>500℃have occurred in the Motuo fault zone in the past,and that the fault maintained an oxidizing environment with weak fluid action during these earthquakes.Our results reveal the seismogenic environment of the Motuo fault zone,and they are potentially important for the evaluation of the regional stability in the eastern Himalayan syntaxis.
基金supported by the National Natural Science Foundation of China(Nos.U2244227,U2244226,42177172)the National Key R&D Program of China(No.2022YFC3004301)China Geological Survey Project(No.DD20230538)。
文摘Frequent glacier-related watershed geohazard chains are causing severe damage to life and infrastructure,reported consistently from the Eastern Himalayan Syntaxis.This paper presents a systematic method for researching geohazard,from regional to individual scale.The methodology includes the establishment of geological chain inventories,discrimination of geohazard chain modes,analyses of dynamics and dam breaches,and risk assessments.The following results were obtained:(1)In the downstream of Yarlung Zangbo River,175 sites were identified as high-risk for river blockage disasters,indicating the development of watershed geohazards.Five geohazard chain modes were summarized by incorporating geomorphological characteristics,historical events,landslide zoning,and materials.The risk areas of typical hazard were identified and assessed using InSAR data.(2)Glacier-related watershed geohazard chains are significantly different from traditional landslides.A detailed inversion analysis was conducted on the massive rock-ice avalanche in the Sedongpu gully in 2021.This particular event lasted roughly 300 seconds,with a maximum flow velocity of 77.2 m/s and a maximum flow height of 93 meters.By scrutinizing the dynamic processes and mechanical characteristics,mobility stages and phase transitions can be divided into four stages.(3)Watershed geohazard chains tend to block rivers.The peak breach discharge of the Yigong Landslide reached 12.4×10^(4) m^(3)/s,which is 36 times the volume of the seasonal flood discharge in the Yigong River.Megafloods caused by landslide dam breaches have significantly shaped the geomorphology.This study offers insights into disaster patterns and the multistaged movement characteristics of glacier-related watershed geohazard chains,providing a comprehensive method for investigations and assessments in glacial regions.
基金The National Key Research and Development Program of China(No.2021YFC2901903)the National Key Research and Development Program of China(No.2023YFC2906805)+1 种基金the Second Comprehensive Scientific Expedition to the Qinghai-Tibet Plateau(No.2019QZKK0806)the Geological Survey Project of China Geological Survey,(Nos.DD20240071,DD20240014,DD20211690,DD20240069)。
文摘The Gabo lithium deposit represents a newly discovered pegmatite-type lithium deposit within the Himalayan metallogenic belt.The tourmaline-muscovite granite,the largest leucogranite in the mining area,displays a close spatial correlation with the Li-pegmatite veins.This study aims to examine the genesis of tourmaline and evaluate the significance and potential of pegmatite lithium deposits.Tourmaline is extensively distributed in tourmaline-muscovite granite at Gabo deposit in Luozha county(Xizang).Investigation of the compositional and in situ boron isotopes of the tourmaline revealed that the tourmalines mainly belong to the schorl group and exhibit uniform elevated Li-Sn contents andδ^(11)B values(-11.6‰to-10.5‰).This indicates that the tourmaline mainly crystallized from a boron-rich granitic magma undergoing enrichment in elemental lithium during the tourmaline crystallization process.Compared with the principal rare metal leucogranite-pegmatites in the Himalayan orogen,it is proposed that the elevated lithium(Li)content of tourmaline serves as an eff ective mineral indicator for the highly evolved pegmatite-type rare metal deposits.
文摘1 Himalayan salt,a pink organic variety of the essential food sourced from Pakistan,is becoming increasingly popular in China,fueled by growing demand from quality‑conscious consumers.Himalayan salt is on the dining tables of more Chinese consumers on occasions such as camping,barbecue parties and grilling steak at home,and it has been used to improve taste and for decorative purposes.
基金the State Forestry Administration in providing financial support for this study
文摘The Himalayan Griffon(Gyps himalayensis), occurring mainly in the Tibetan Plateau, is one of the scavengers of Old World vultures. As of now, knowledge about the Himalayan Griffon in China remains scarce. Estimates of its number, habitat, and conservation status were carried out in 2003, 2009 and 2102 in the Lhasa River Valley, where we paid particular attention to the population living at the Drigung Thel Monastery, Mzizhokunggar County. The resident species occupies alpine meadows in the daytime and roosts at the upper parts of cliffs at night between 4400–5000 m elevation. The number of individual birds of the Himalayan Griffon around the monastery was estimated as 230 in 2003, 250 in 2009 and 200 in 2012. This population is considered relatively stable, thanks to the current conservation measures by Buddhist monks and local people. Given the lack of any baseline information, it is difficult for us to recommend and provide any effective conservation measures.
基金the State Forestry Administration to provide financial support to this study
文摘The Himalayan Monal (Lophophorus impejanus) is a national first grade protected species in China.So far,current knowledge of the Himalayan Monal in China is still poor.An estimate of its distribution,numbers and habitat was conducted during a two-year investigation from 2008 to 2009 in southern Tibet,especially in Lhozhag,Cona and Yadong counties.In total,12 sightings of the Himalayan Monal were recorded during the study period.Our data suggest that this bird is mainly found in Medog,Zayu,Cona,Lhunze,Lhozhag,Nyalam,Dingjie,Gamba and Yadong counties on the southern slopes of the Himalayas.Its western-most location was confirmed to be Nyalam County.The bird ranges in elevation from 3800 to 4300 m in the summer and from 3200 to 3500 m in the winter.We sighted 36-37 individual birds,consisting of 8-10 males,16-20 females and 7-8 sub-adults inhabiting the area around the Kajiu Monastery in Lhozhag County.The birds are mainly found in rocky forests,interspersed with steep slopes,cliffs and alpine meadows at elevations between 3800 and 4000 m.The population density of the Himalayan Monal near the Kajiu Monastery is 2.03 individual birds per km2,much larger than that of Yadong and Cona counties (0.052 individuals per krn2).
文摘Located in southern Ningxia Hui Autonomous Region,northwest China,the Liupan Mountain National Nature Reserve covers a total area of 26,783.64 hectares.Established in 1982 and upgraded to national status in 1988,it protects a vital temperate mountainous forest ecosystem on the Loess Plateau.The reserve is centred around the Liupan Mountain range,one of China’s youngest mountain chains,formed by Himalayan tectonic movements.
基金the National Natural Science Foundation of China (Grants 49802020,49732100 , 40172074) the Specific Project forthe Authors of the Best Dissertations of Chinese Universifies and Colleges (200022).
文摘The eastern Himalayan syntaxis in Namjagbarwa is a high-grade metamorphicterrain formed by the India-Eurasia collision and northward indentation of the Indian continent intoAsia. Right- and left-lateral slip zones were formed by the indentation on the eastern and westernboundaries of the syntaxis respectively. The Dongjug-Mainling fault zone is the main shear zone onthe western boundary. This fault zone is a left-lateral slip belt with a large component ofthrusting. The kinematics of the fault is consistent with the shortening within the syntaxis, andthe slipping history along it represents the indenting process of the syntaxis. The Ar-Archronological study shows that the age of the early deformation in the Dongjug-Mainling fault zoneranges from 62 to 59 Ma. This evidences that the India-Eurasia collision occurred in the earlyPaleocene in the eastern Himalayan syntaxis.
文摘The western boundary of the Eastern Himalayan Syntaxis (EHS) is a deformation belt up to 30km wide (Fig.1). Trending ca. N35°E, it separates the Gangdise magmatic belt in the west from the gneiss of EHS in the east. Its rock association, mica\|schist, quartzite, marble, and amphibolite, can be traced to the south to Gangdise belt and they were probably metamorphosed from the sediments along Yarlung Zangbo. This belt consists of several intensive deformation zones, the largest one of which is along the belt’s western margin from Dongjug to Mainling and we called this ca. 10km wide shear zone as the Dongjug\|Mainling shear zone (DMSZ).DMSZ experienced earlier ductile shear and later ductile\|brittle normal faulting. The earlier deformation produced mylonitic rocks. Their foliation trends N30°～40°E and dips northwest with the angle ranging from 55°to 80°, steepening northeastward. The penetrative kinematic lineation in the rocks has a varying attitude along the trend of DMSZ. It dips southwest with an angle of ca.35° in the southwest near Mainling, whereas dips northeast in the northeast. Moreover, the northeast dipping lineation steepens northeastwards, e.g., its angle ranges form 30° to 45° in the segment from Serkyim La to Dongjug but becomes 60～70° in the northeast most in another zone near Parlung. Kinematic indicators show that the motion of DMSZ had a left\|lateral slipping component, but the vertical motion components were different in the southwest from the northeast. From Serkyim La to the northeast, DMSZ had a kinematics of NW plate (Gangdise belt) thrusting over the SE plate (EHS) and its thrusting component increased toward northeast. However, the DMSZ has a vertical motion with the SE plate (EHS) as the uplifting plate.
基金supported by the Project of the 12th Five-year National Sci-Tech Support Plan of China(No.2011BAK12B09)the National Natural Science Foundation of China(41402321,41502313)+1 种基金the Project of China Geological Survey(No.12120113038000)China Special Project of Basic Work of Science and Technology(No.2011FY110100-2)
文摘The eastern Himalayan syntaxis is one of the most tectonically active and earthquake-prone regions on Earth where earthquake-induced geological disasters occur frequently and caused great damages. With the planning and construction of Sichuan-Tibet highway, Sichuan-Tibet railway and hydropower development on the Yarlung Zangbo River etc. in recent years, it is very important to evaluate the seismic landslide hazard of this region. In this paper, a seismic landslide hazard map is produced based on seismic geological background analysis and field investigation using Newmark method with 10% PGA exceedance probabilities in future 50 years by considering the influence of river erosion, active faults and seismic amplification for the first time. The results show that the areas prone to seismic landslides are distributed on steep slopes along the drainages and the glacier horns as well as ridges on the mountains. The seismic landslide hazard map produced in this study not only predicts the most prone seismic landslide areas in the future 50 years but also provides a reference for mitigation strategies to reduce the exposure of the new building and planning projects to seismic landslides.
文摘The seismotectonic characteristics of ten repeated earthquake swarm sequence within a seismic cluster along Jiali Fault in eastern Himalayan Syntaxis(EHS) have been analysed.The swarms are spatially disposed in and around Yigong Lake(a natural lake formed by blocking of Yigong River by landslide) and are characterized by low magnitude,crustal events with low to moderate b values.Ms:mb discriminant functions though indicate anomalous nature of the earthquakes within swarm but are considered as natural events that occurred under condition of high apparent stress and stress gradients.Composite fault plane solutions of selected swarms indicate strike-slip sense of shear on fault planes;solution parameters show low plunging compression and tensional axes along NW-SE and NE-SW respectively with causative fault plane oriented ENE-WSW.dipping steeply towards south or north.The fault plane is in excellent agreement with the disposition and tectonic movement registered by right lateral Jiali Fault.The process of pore pressure perturbation and resultant ’r—t plot’ with modelled diffusivity(D = 0.12 m^2/s) relates the diffusion of pore pressure to seismic sequence in a fractured poro-elastic fluid saturated medium at average crustal depth of 15-20 km.The low diffusivity depicts a highly fractured interconnected medium that is generated due to high stress activity near the eastern syntaxial bent of Himalaya.It is proposed that hydro fracturing with respect to periodic pore pressure variations is responsible for generation of swarms in the region.The fluid pressure generated due to shearing and infiltrations of surface water within dilated seismogenic fault(Jiali Fault) are causative factors.
文摘Background： The fragile landscapes of the Himalayan region are highly susceptible to natural hazards, and there is ongoing concern about current and potential climate change impacts. This study provides background information on India＇s Western Himalayas and reviews evidence of warming as well as variability in precipitation and extreme events.Methods： Understanding and anticipating the impacts of climate change on Himalayan forest ecosystems and the services they provide to people are critical. Efforts to develop and implement effective policies and management strategies for climate change mitigation and adaptation requires particular new research initiatives. The various studies initiated and conducted in the region are compiled here.Results： Several new initiatives taken by the Himalayan Forest Research Institute in Shimla are described. This includes new permanent observational field studies, some with mapped trees, in high altitude transitional zones for continuous monitoring of vegetation response. We have also presented new strategies for mitigating potential climate change effects in Himalayan forest ecosystems.Conclusions： Assessment of the ecological and genetic diversity of the Himalayan conifers is required to evaluate potential responses to changing climatic conditions. Conservation strategies for the important temperate medicinal plants need to be developed. The impact of climate change on insects and pathogens in the Himalayas also need to be assessed. Coordinated efforts are necessary to develop effective strategies for adaptation and mitigation.
基金funded by the National Natural Science Foundation of China (Nos. 41772034, 41174076 and 41672041)the China Postdoctoral Science Foundation (No. 2017M620508)support from Peking University Boya Postdoctoral Fellowship
文摘Water content in nominally anhydrous minerals （NAMs） of the high-pressure （HP） metamorphic rocks controls the thermal structure, rheology and partial melting of orogenic belts. This paper conducts a systematic analysis of water in NAMs of the HP granulites from the Greater Himalayan Sequence （GHS）, representing the thickened lower crust of the eastern Himalayan Orogen. The present result shows that the garnet, clinopyroxene, feldspar, quartz and kyanite contain 188 ppm-432 ppm, 193 ppm-547 ppm, 335 ppm-1 053 ppm, 125 ppm-185 ppm and 89 ppm H2O, respectively, and indicates that the thickened lower crust of the Himalayan Orogen is relatively wet rather than dry. The considerable concentrations of water in the HP granulites are expected to promote the rheological weakening of the metamorphic core of the Himalayan Orogen, providing a favorable evidence for the channel flow model of the exhumation of thickened lower crust.
文摘In this paper, we analyzed the long-term changes in temperature and precipitation in the Hindu Kush Himalayan (HKH) region based on climate datasets LSAT-V1.1 and CGP1.0 recently developed by the China Meteorological Administration. The analysis results show that during 1901e2014 the annual mean surface air temperature over the whole HKH has undergone a significant increasing trend. We determined the change rates in the mean temperature, mean maximum temperature, and mean minimum temperature to be 0.104 C per decade, 0.077 C per decade, and 0.176 C per decade, respectively. Most parts of the HKH have experienced a warming trend, with the largest increase occurring on the Tibetan Plateau (TP) and south of Pakistan. The trend of precipitation for the whole HKH is characterized by a slight decrease during 1901e2014. During 1961e2013, however, the trend of the annual precipitation shows a statistically significant increase, with a rate of 5.28% per decade and has a more rapid increase since the mid-1980s. Most parts of northern India and the northern TP have experienced a strong increase in the number of precipitation days (daily rainfall 1 mm), whereas Southwest China and Myanmar have experienced a declining trend in precipitation days. Compared to the trends in precipitation days, the spatial pattern of trends in the precipitation intensity seems to be more closely related to the terrain, and the higher altitude areas have shown more significant upward trends in precipitation intensity during 1961e2013.
文摘In the Indian Himalayan Region, th studies focused on diversity of the plants used fo treating liver diseases/ailments have not been carried out so far. Therefore, the present attempt has been made to study the diversity, distribution pattern and conservation status of the plant species used fo treating liver diseases/ailments in that region. A tota of 138 species (35 species of trees, 22 shrubs and 8 herbs) belonging to 98 genera in 60 families hav been recorded. Amongst the families, Euphorbiacea (9 species), and altitudinal zone <1,800 m, (i.e., 11 species) are rich in species. Traditionally, variou plant parts, such as roots/rhizomes/tubers (46 species), leaves (31), whole plants (30), barks (15) fruits (13), seeds and unspecified parts (8 each), and inflorescence (1) are used for the treatment of live diseases/ailments. 34 species are native, 3 ar endemic and 15 near endemic. 7 species ar categorized as Critically Endangered (Betula utilis) Endangered (Podophyllum hexandrum, Ephedra gerardiana, and Nardostachys grandiflora) and Vulnerable (Bergenia ligulata, B. stracheyi, and Hedychium spicatum) using new IUCN criteria Available chemical composition of plant parts used fo the treatment of liver diseases/ailments have beengiven. Assessment of the populations of threatened species, development of an appropriate strategy, action plan for the conservation and sustainable utilization of such components of plant diversity are suggested.
文摘During the last 40Ma the marine 87 Sr/ 86 Sr record shows a rapid rise (from 0 7078 to 0 7092) [1] , a trend which has been linked to the Himalayan Orogeny [2] . Indeed, many Himalayan rivers, principally those of the Ganges\|Brahmaputra system, display high 87 Sr/ 86 Sr relative to [Sr] [3] . Theories concerning the cause of this radiogenic Sr enrichment are diverse, but our results suggest that Lesser Himalayan carbonate\|rich lithologies play a vital role [4,5] .The Bhote Kosi originates in Tibet at ca.5km elevation from Tibetan Sedimentary Series (TSS) bedrock, before traversing the High Himalayan Crystalline Series (HHCS) and Lesser Himalaya (LH) of eastern Nepal, joining the Indrawati (at ca.0 6km elevation) to form the Sun Kosi, part of the Ganges system. Carbonates, calc\|silicates and silicates have been identified from the TSS, HHCS and LH, and the Bhote Kosi provides an opportunity to study the influence of these upon fluvial chemistry. Interest is focused on the cause of a rapid rise in riverine Sr\|isotope ratios immediately downstream of the Main Central Thrust (MCT) and the role of carbonate\|rich lithologies exposed in this section. Similar lithologies are lacking in the catchment of a second Nepalese river system, the Lantang Khola—Trisuli, sampled during the same period, and used as a baseline indicator for the effect of LH carbonates on the dissolved load of the Bhote Kosi.
文摘The genus Rhododendron of Indian Himalayan Region (IHR) has been enumerated in the present paper. A total of 87 species, 12 subspecies and 8 varieties of Rhododendrons recorded in IHR, among these 6 species and one subspecies are reported from Western Himalaya. The maximum concentration of 86% observed in Arunachal Pradesh (75 species). The species of Rhododendrons exhibit significant diversity in habit and broad range of distribution from the altitude of 800-6000 m. and the best range is observed in 3001-3500 m altitudes. In analysis revealed 20 taxa are endemic, 30 are rare, 24 are threatened / endangered, 3 are vulnerable and 47 taxa have to be assessed. The major threats to rhododendrons are deforestation and unsustainable extraction for firewood and incense by local people has been discussed.
