Dynamic Changes in Per Capita Net Income of Rural Residents in Nyingchi City of Tibet

Through an in-depth analysis of the per capita net income of rural residents in Nyingchi City,it was known that the per capita net income of rural residents in Nyingchi City was increasing at high speed in recent 10 years. However,the wage income,household operating income,and agricultural income gap constitute the major factors influencing the gap of the per capita net income of rural residents in Nyingchi City. Finally,it came up with recommendations including promoting the reasonable flow of labor to the secondary and tertiary industries,increasing the wage income and transfer income of rural residents,accelerating the construction of small towns in rural areas,promoting the development of rural cooperatives,implementing the strategy of " benefiting farmers and strengthening tourism",promoting integration of agriculture and eco-tourism,promoting the development of modern agriculture,and expanding diversified production income of farmers.

Tibet's First Eco-Tour Villagein Nyingchi

Gongzong Village lies in mountains skirted by National Highway No.318 in Nyingchi. All the villagers have home telephones, earning the area the nickname of "telephone village". But the meaning of its real name in Tibetan is"bumper harvest of fruit" or "bumper harvest of grapes."Sprawling along the mountain slopes, Gongzong Village is a world of orchards. A stream fed by a gurgling fountain cuts through the village before meeting the Nying River.

Photosynthetic Characteristics of Three Fig Cultivars in Nyingchi, Tibet

The photosynthetic characteristics of three excellent fig cultivars introduced, Branswick, Qingpi and Xinjiang Zaohuang, were compared in the paper, in order to provide reference for the cultivation and breeding of different fig cultivars in Tibet. The daily variation of photosynthetic parameters of the three excellent fig cultivars, Branswick, Qingpi and Xinjiang Zaohuang, which were introduced and cultivated by XiZang Agriculture and Animal Husbandry College in Bayi District, Nyingchi City, Tibet, were measured and compared. The results showed that the net photosynthetic rates (Pn) of three fig cultivars were Qingpi > Branswick > Xinjiang Zaohuang, and the daily variation curves of net photosynthetic rate were all of unimodal pattern. The daily variation curves of transpiration rate (Tr), water utilization efficiency (WUE) and efficiency for solar energy utilization (Pn/Par) of different fig cultivars showed unimodal pattern;the daily variation curve of intercellular CO2 content (Ci) showed decline pattern;the daily variation curve of stomatal conductance (Gs) showed bimodal pattern;Pn had extremely positive correlation with Tr, WUE, Gs, Par, Pn/Par and Ta.

Estimation of Biodiversity Conservation Value of Forest Ecosystem in Nyingchi Prefecture of Tibet

The estimation was made for the conservation value of forest ecosystem biodiversity in Nyingchi Prefecture of Tibet.The results showed that the annual economic benefits of biodiversity in Nyingchi Prefecture were about 21.4 billion yuan,and the annual economic benefits of global biodiversity were about 3 trillion USD.It indicated that the ecological value of forest ecosystem in Nyingchi Prefecture is high,forest ecosystem has extremely important ecological value.Therefore,in the decision-making process,it is necessary to strengthen the protection of forest ecosystem,with particular emphasis on the restoration of damaged ecosystem.

Investigation and Analysis on the Management Standard of Blood Glucose Monitoring for Clinical Nurses in Nyingchi Region of Tibet

Background: In participating in the medical support work in the Nyingchi area of Tibet, the author found that the medical education resources in this area are scarce, and the clinical nurses in this area have relatively insufficient knowledge about blood glucose monitoring and management. Accurately understanding the knowledge-attitude/belief-practice (KAP) level of nurses in Nyingchi area on blood glucose management is of great significance to the development of blood glucose monitoring management guidance for nurses in this area. Therefore, this study investigated the current status of the management of blood glucose monitoring management standards for clinical nurses in Nyingchi, Tibet. Objective: To investigate and analyze the current situation of clinical nurses in Nyingchi region of Tibet to grasp the regulation of blood glucose monitoring and guide the implementation of the norm of blood glucose monitoring for clinical nurses. Methods: The research survey was carried out from March to April 2020. Random sampling method was used to select 134 clinical in-service nurses in Nyingchii, Tibet. The self-designed knowledge-attitude/belief-practice survey questionnaire for clinical nurses’ blood glucose monitoring and management in Tibet was used. Nurses’ blood glucose monitoring management “KAP” scores and related influencing factors are analyzed. Results: Blood sugar monitoring and management knowledge score is (36.78 ± 6.80), attitude dimension is (42.48 ± 6.42), practice dimension is (61.87 ± 10.24) and total score is (304.73 ± 36.24). The nurse’s department and whether to participate in diabetes training are the main influencing factors of the blood glucose monitoring management norms, knowledge and behavior (both P < 0.05). Conclusion: The standard knowledge of blood glucose monitoring and management of clinical nurses in Nyingchi region of Tibet is at the middle level, positive attitude and unsatisfactory behavior. Nursing managers should conduct standardized training for clinical nurses in blood glucose monitoring, develop the training mode of diabetes specialty nursing talents in Nyingchi area, and construct a complete management system of diabetes specialty nursing.

Thoughts on Pairing Assistance to Tibet for Promoting Agricultural High-quality Development in Southern Tibet from the Perspective of Agricultural Power

In the new era,there is an urgent need to further promote pairing assistance to Tibet,promote the simultaneous construction of a strong agriculture in Tibet and the China's Mainland,and compose a Chinese-style modernization.Southern Tibet,located in the southeastern part of the Tibet Autonomous Region,includes Shannan City and Nyingchi City,is a region assisted by four provincial partners including Hubei Province.This paper introduces the agricultural environment in southern Tibet,studies its agricultural characteristics,and analyzes the main issues of its pairing assistance.Taking forging the strong consciousness of the Chinese national community as the main line,the paper explores strategies for promoting agricultural high-quality development in southern Tibet through pairing assistance to Tibet from the perspective of agricultural power,and proposes some strategies,such as inheriting agricultural cultural heritage,promoting the upgrading of modern seed industry,enhancing the characteristic advantages of highland barley(naked barley)and animal husbandry industries,and developing edible fungi and cold water fish industries.

Mineral Geochemistry of Apatite in the Jiama PorphyrySkarn Deposit,Tibet and its Geological Significance

The Jiama deposit,a significant porphyry-skarn-type copper polymetallic deposit located within the Gangdese metallogenic belt in Tibet,China,exemplifies a typical porphyry metallogenic system.However,the mineral chemistry of its accessory minerals remains under-examined,posing challenges for resource assessment and ore prospecting.Utilizing electron microprobe analysis and LA-ICP-MS analysis,this study investigated the geochemical characteristics of apatite in ore-bearing granite and monzogranite porphyries,as well as granodiorite,quartz diorite,and dark diorite porphyries in the deposit.It also delved into the diagenetic and metallogenic information from these geochemical signatures.Key findings include:(1)The SiO_(2) content,rare earth element(REE)contents,and REE partition coefficients of apatite indicate that the dark diorite porphyry possibly does not share a cogenetic magma source with the other four types of porphyries;(2)the volatile F and Cl contents in apatite,along with their ratio,indicate the Jiama deposit,formed in a collisional setting,demonstrates lower Cl/F ratios in apatite than the same type of deposits formed in a subduction environment;(3)compared to non-ore-bearing rock bodies in other deposits formed in a collisional setting,apatite in the Jiama deposit exhibits lower Ce and Ga contents.This might indicate that rock bodies in the Jiama deposit have higher oxygen fugacity.Nevertheless,the marginal variation in oxygen fugacity between ore-bearing and non-ore-bearing rock bodies within the deposit suggests oxygen fugacity may not serve as the decisive factor in the ore-hosting potential of rock bodies in the Jiama deposit.

Geochronology and Geochemistry of Ore-related Granitoids in the Giant Gariatong Rb Deposit,Tibet and Implications for Rb Metallogeny in China

Rubidium(Rb)deposits mostly occur in the South China and Central Asia orogenic belts and are often closely associated with highly differentiated granites.This study investigates a newly-discovered giant Rb deposit at Gariatong in the Central Lhasa terrane in Tibet.Detailed field studies and logging data revealed that the Rb mineralization mainly occurs in monzogranite and is related to greisenization.LA-ICP-MS U-Pb dating of zircon yielded ages of 19.1±0.2 Ma and 19.0±0.2 Ma for greisenized monzogranite and fresh monzogranite,respectively.The monzogranites are characterized as strongly peraluminous,with high contents of SiO2,Al2O3,K2O and Na2O as well as a high differentiation index.They are enriched in light rare earth and large ion lithophile elements with significant negative Eu anomalies and depleted high fieldstrength elements.Petrological and geochemical features of these ore-related monzogranites suggest that they are highly fractionated S-type granites,derived from remelting of crustal materials in a post-collisional setting.The geochemistry of zircon and apatite points to a low oxygen fugacity of the ore-related monzogranite during the magma’s evolution.The discovery of the Gariatong Rb deposit suggests that the Central Lhasa terrane may be an important region for rare metal mineralization.

Present-day Upper-crustal Strain Rate Field in Southeastern Tibet and its Geodynamic Implications:Constraints from GPS Measurements with ABIC Method

The Earth’s surface kinematics and deformation are fundamental to understanding crustal evolution.An effective research approach is to estimate regional motion field and deformation fields based on modern geodetic networks.If the discrete observed velocity field is obtained,the velocity related fields,such as dilatation rate and maximum shear strain rate,can be estimated by applying varied mathematical approaches.This study applied Akaike's Bayesian Information Criterion(ABIC)method to calculate strain rate fields constrained by GPS observations in the southeast Tibetan Plateau.Comparison with results derived from other three methods revealed that our ABIC-derived strain rate fields were more precise.The maximum shear strain rate highlighted the Xianshuihe–Xiaojiang fault system as the main boundary for the outward migration of material in southeastern Tibet,indicating rotation of eastern Tibet material around the eastern Himalaya rather than whole extrusion along a fixed channel.Additionally,distinct dilatation rate patterns in the northeast and southwest regions of the fault system were observed.The northeast region,represented by the Longmenshan area,exhibited negative dilatational anomalies;while the southwest region,represented by the Jinsha River area north of 29°N,displayed positive dilatational anomalies.This indicates compression in the former and extension in the latter.Combined with deep geophysical observations,we believe that the upper and lower crusts of the Jinsha River area north of 29°N are in an entire expanding state,probably caused by the escape-drag effect of material.The presence of a large,low-viscosity region south of 29°N may not enable the entire escape of the crust,but instead result in a differential escape of the lower crust faster than the upper crust.

Genesis of the Nuri Cu-W-Mo Deposit,Tibet,China:Constraints from in situ Trace Elements and Sr Isotopic Analysis of Scheelite

The Nuri deposit is the only Cu-W-Mo polymetallic deposit with large-scale WO3 resources in the eastern section of the Gangdese metallogenic belt,Tibet,China.However,the genetic type of this deposit has been controversial since its discovery.Based on a study of the geological characteristics of the deposit,this study presents mineralization stages,focusing on the oxide stage and the quartz-sulfide stage where scheelite is mainly formed,referred to as Sch-A and Sch-B,respectively.Through LA-ICP-MS trace element and Sr isotope analyses,the origin,evolutionary process of the oreforming fluid and genesis of the ore deposit are investigated.Scanning Electron Microscope-Cathodoluminescence(SEMCL)observations reveal that Sch-A consists of three generations,with dark gray homogenous Sch-A1 being replaced by relatively lighter and homogeneous Sch-A2 and Sch-A3,with Sch-A2 displaying a gray CL image color with vague and uneven growth bands and Sch-A3 has a light gray CL image color with hardly any growth band.In contrast,Sch-B exhibits a‘core-rim’structure,with the core part(Sch-B1)being dark gray and displaying a uniform growth band,while the rim part(Sch-B2)is light gray and homogeneous.The normalized distribution pattern of rare earth elements in scheelite and Sr isotope data suggest that the early ore-forming fluid in the Nuri deposit originated from granodiorite porphyry and,later on,some country rock material was mixed in,due to strong water-rock interaction.Combining the O-H isotope data further indicates that the ore-forming fluid in the Nuri deposit originated from magmatic-hydrothermal sources,with contributions from metamorphic water caused by water-rock interaction during the mineralization process,as well as later meteoric water.The intense water-rock interaction likely played a crucial role in the precipitation of scheelite,leading to varying Eu anomalies in different generations of scheelite from the oxide stage to the quartz-sulfide stage,while also causing a gradual decrease in oxygen fugacity(fO2)and a slow rise in pH value.Additionally,the high Mo and low Sr contents in the scheelite are consistent with typical characteristics of magmatic-hydrothermal scheelite.Therefore,considering the geological features of the deposit,the geochemical characteristics of scheelite and the O-H isotope data published previously,it can be concluded that the genesis of the Nuri deposit belongs to porphyry-skarn deposit.

Spatial and Temporal Distribution Characteristics of Solar Energy Resources in Tibet

The Tibet Plateau is one of the regions with the richest solar energy resources in the world.In the process of achieving carbon neutrality in China,the development and utilization of solar energy resources in the region will play an important role.In this study,the gridded solar resource data with 1km resolution in Tibet were obtained by spatial correction and downscaling of SMARTS model.On this basis,the spatial and temporal distribution characteristics of solar energy resources in the region in the past 30 years(1991–2020)are finely evaluated,and the annual global horizontal radiation resource is calculated.The results show that:1)The average annual global horizontal radiation amount in Tibet is 1816 kWh/m^(2).More than 60%of the area belongs to the“Most abundant”(GHI≥1750 kWh/m^(2))area of China’s solar energy resources category A,and nearly 40%belongs to the“Quite abundant”(1400≤GHI<1750)area of China’s solar energy resource category B.2)In space,the solar energy resources in Tibet increased gradually from north to south and from east to west.Lhasa,Central and Eastern Shigatse,Shannan,and Southwestern Ali are the most abundant cities,with a maximum annual radiation level of 2189 kWh/m2.3)In terms of time,the total horizontal radiation in Tibet was the highest in May and the lowest in December.74%of the total area belongs to the“Very stable”(R_(w)≥0.47)area of solar resource stability category A,and 26%belongs to the“stable”(0.36≤R_(w)<0.47)area of solar resource stability category B.Solar energy resources in the region show the characteristics of both strong and stable.Average solar energy resources in the region have shown a fluctuating downward trend over the past 30 years,with an average decline of about 12.86(kWh/m2)per decade.4)In terms of solar radiation resources reaching the earth’s surface,the theoretical total amount of annual horizontal radiation in Tibet is about 240.07 billion tons of standard coal or 222.91 billion kilowatts on average.

Three-Dimensional Density Distribution and Seismic Activity along the Guxiang–Tongmai Segment of the Jiali Fault,Tibet

The Guxiang-Tongmai segment of the Jiali fault is situated northeast of the Namche Barwa Syntaxis in northeastern Tibet.It is one of the most active strike-slip faults near the syntaxis and plays a pivotal role in the examination of seismic activity within the eastern Himalayan Syntaxis.New study in the research region has yielded a 1:200000 gravity dataset covering an area 1500 km^(2).Using wavelet transform multiscale decomposition,scratch analysis techniques,and 3D gravity inversion methods,gravity anomalies,fault distributions,and density structures were determined across various scales.Through the integration of our new gravity data with other geophysical and geological information,our findings demonstrate substantial variations in the overall crustal density within the region,with the fault distribution closely linked to these density fluctuations.Disparities in stratigraphic density are important causes of variations in the capacity of geological formations to endure regional tectonic stress.Earthquakes are predominantly concentrated within the density transition zone and are primarily situated in regions of elevated density.The hanging wall stress within the Guxiang-Tongmai segment of the Jiali fault exhibits a notable concentration,marked by pronounced anisotropy,and is positioned within the density differential zone,which is prone to earthquakes.

Quantification of the concrete freeze–thaw environment across the Qinghai–Tibet Plateau based on machine learning algorithms

The reasonable quantification of the concrete freezing environment on the Qinghai–Tibet Plateau(QTP) is the primary issue in frost resistant concrete design, which is one of the challenges that the QTP engineering managers should take into account. In this paper, we propose a more realistic method to calculate the number of concrete freeze–thaw cycles(NFTCs) on the QTP. The calculated results show that the NFTCs increase as the altitude of the meteorological station increases with the average NFTCs being 208.7. Four machine learning methods, i.e., the random forest(RF) model, generalized boosting method(GBM), generalized linear model(GLM), and generalized additive model(GAM), are used to fit the NFTCs. The root mean square error(RMSE) values of the RF, GBM, GLM, and GAM are 32.3, 4.3, 247.9, and 161.3, respectively. The R^(2) values of the RF, GBM, GLM, and GAM are 0.93, 0.99, 0.48, and 0.66, respectively. The GBM method performs the best compared to the other three methods, which was shown by the results of RMSE and R^(2) values. The quantitative results from the GBM method indicate that the lowest, medium, and highest NFTC values are distributed in the northern, central, and southern parts of the QTP, respectively. The annual NFTCs in the QTP region are mainly concentrated at 160 and above, and the average NFTCs is 200 across the QTP. Our results can provide scientific guidance and a theoretical basis for the freezing resistance design of concrete in various projects on the QTP.

Plume-lithosphere interaction in the Comei Large Igneous Province: Evidence from two types of mafic dykes in Gyangze, south Tibet, China

Two suites of mafic dykes,T1193-A and T1194-A,outcrop in Gyangze area,southeast Tibet.They are in the area of Comei LIP and have indistinguishable field occurrences with two other dykes in Gyangze,T0902 dyke with 137.7±1.3 Ma zircon age and T0907 dyke with 142±1.4 Ma zircon age reported by Wang YY et al.(2016),indicating coeval formation time.Taking all the four diabase dykes into consideration,two different types,OIB-type and weak enriched-type,can be summarized.The“OIB-type”samples,including T1193-A and T0907 dykes,show OIB-like geochemical features and have initial Sr-Nd isotopic values similar with most mafic products in Comei Large Igneous Provinces(LIP),suggesting that they represent melts directly generated from the Kerguelen mantle plume.The“weak enriched-type”samples,including T1194-A and T0902 dykes,have REEs and trace element patterns showing withinplate affinity but have obvious Nb-Ta-Ti negative anomalies.They show uniform lowerεNd(t)values(−6‒−2)and higher 87Sr/86Sr(t)values(0.706‒0.709)independent of their MgO variation,indicating one enriched mantle source.Considering their closely spatial and temporal relationship with the widespread Comei LIP magmatic products in Tethyan Himalaya,these“weak enriched-type”samples are consistent with mixing of melts from mantle plume and the above ancient Tethyan Himalaya subcontinental lithospheric mantle(SCLM)in different proportions.These weak enriched mafic rocks in Comei LIP form one special rock group and most likely suggest large scale hot mantle plume-continental lithosphere interaction.This process may lead to strong modification of the Tethyan Himalaya lithosphere in the Early Cretaceous.

TIBETAN NEW YEAR

This year,the Tibetan New Year,known as Losar,falls on Feb.21.It is the most traditional and important festival in Tibet,and also one of the national intangible cultural heritages.

Coherent Chemical Variation Trends of the 55-25 Ma Magmatic Rocks in SE Tibet:N-S Direction Lithospheric Stretching of Eurasia during Early Stage of India-Eurasia Collision

The progressive indentation of India into Eurasia generated an E-W-trending orthogonal collision belt and a N-S-trending oblique collision belt.Compiling available data reveals that~70%of the Cenozoic igneous rocks in eastern and southeastern Tibet are concentrated within an ENE-trending,~550-km long and~250-km wide magmatic zone(CMZ)that once separated the orthogonal and oblique collision belts.The Latitude 26°N Line is now its southern boundary.The onset timing of magmatism of the CMZ varies gradually from~55 Ma in the westernmost part to~27 Ma in the easternmost.Then the magmatism successively occurred and suddenly stopped at~25 Ma.The segmented and coherent chemical variation trends found suggest that the CMZ magmatic rocks were formed due to partial melting of the heterogeneous upper mantle and crusts of Eurasia.Subduction of Paleo-and Neotethyan oceanic plates generated this compositional and mineralogical heterogeneity.Combined with available geophysical data,the CMZ was diachronously formed in response to asthenosphere upwelling induced by NNW-SSE-direction lithosphere stretching.The difference in responses of the orthogonal and oblique collision belts to the indentation of the Indian continent has led to this lithosphere stretching.

The long-lived partial melting of the Greater Himalayas in southern Tibet, constraints from the Miocene Gyirong anatectic pegmatite and its prospecting potential for rare element minerals

The Cenozoic Himalayan leucogranite-pegmatite belt has been a hotspot for rare metal exploration in recent years.To determine the genesis of the pegmatite in the Himalayan region and its relationship with the Greater Himalayan Crystalline Complex(GHC),the Gyirong pegmatite in southern Tibet was chosen for geochronological and geochemical studies.The dating analyses indicate that the U-Th-Pb ages of zircon,monazite,and xenotime exhibit large variations(38.6‒16.1 Ma),with the weighted average value of the four youngest points is 16.5±0.3 Ma,which indicates that the final stage of crystallization of the melt occurred in the Miocene.The age of the muscovite Ar-Ar inverse isochron is 15.2±0.4 Ma,which is slightly later than the intrusion age,showing that a cooling process associated with rapid denudation occurred at 16‒15 Ma.TheεHf(t)values of the Cenozoic anatectic zircons cluster between−12 and−9 with an average of−11.4.The Gyirong pegmatite shows high contents of Si,Al,and K,a high Al saturation index,and low contents of Na,Ca,Fe,Mn,P,Mg,and Ti.Overall,the Gyirong pegmatite is enriched in Rb,Cs,U,K,Th and Pb and depleted in Nb,Ta,Zr,Ti,Eu,Sr,and Ba.The samples show a high 87Sr/86Sr(16 Ma)ratio of ca.0.762 and a lowεNd(16 Ma)value of−16.0.The calculated average initial values of 208Pb/204Pb(16 Ma),207Pb/204Pb(16 Ma)and 206Pb/204Pb(16 Ma)of the whole rock are 39.72,15.79 and 19.56,respectively.The Sr-Nd-Pb-Hf isotopic characteristics of the Gyirong pegmatite are consistent with those of the GHC.This study concludes that the Gyirong pegmatite represents a typical crustal‒derived anatectic pegmatite with low metallogenic potential for rare metals.The Gyirong pegmatite records the long‒term metamorphism and partial melting process of the GHC,and reflects the crustal thickening caused by thrust compression at 39‒29 Ma and the crustal thinning induced by extensional decompression during 28‒15 Ma.

Incorporating Exercise Efficiency to Evaluate the Accessibility and Capacity of Medical Resources in Tibet, China

Accessibility and capacity of medical resources are key for the health care and emergency response, while the efficiency of the medical resources is very much limited by hypoxia in Tibet, China.Through introducing exercise efficiency, this study explores the accessibility of township residence to county-ship medical resources in Tibet using weighted mean travel time(WMT), and evaluates the medical capacity accordingly.The results show that: 1) the average travel time of township residence to county-level hospital is around2 h by motor vehicle in Tibet.More than half of the population can not reach the county-ship hospital within 1 h, 33.24% of the population can not reach within 2 h, and 3.75% of the population can not reach within 6 h.2) When considering the catchment of the medical resources and the population size, the WMT of the county-ship medical resources ranges from 0.25 h to 10.92 h.3) After adjusted by travel time and exercise efficiency, the county-ship medical capacity became more unequal, with 38 out of 74 counties could not meet the national guideline of 1.8 medical beds per 1000.4) In total, there are 17 counties with good WMT and sufficient medical resources,while 13 counties having very high WMT and low capacity of medical resources in Tibet.In the end, suggestions on medical resources relocation and to improve the capacity are provided.This study provides a method to incorporate exercise efficiency to access the accessibility and evaluate medical capacity that can be applied in high altitude ranges.

Spatiotemporal distribution of regional landslides and erosion rates in Southeastern Tibet

The difficulty in estimating ages of regional landslides hampers to assess frequency of landslides and hence to quantitatively assess regional landslide hazard.In this study,we used radiocarbon dating of organic sediment on boulder rock varnish to estimate landslide ages in Langxian(LX)arid region in southeastern Tibet.Samples of rock varnish with organic sediment were collected on site for radiocarbon dating,leading to landslide ages from 1880±30 to 18,430±30 yr B.P.To measure surface roughness characteristics of 109 remotely-mapped large bedrock landslide deposits,we estimated average standard deviation of slope(SDS)over an area of~640 km^(2) by calculating the slope gradient of each raster cell and using a rectangular moving window method in Arc Map from a 5 m-resolution Digital Elevation Model generated from helicopterobtained photographs.Combing estimated landslide ages(t)with average surface roughness of mapped landslide deposits(R)quantified by SDS,we fit an exponential landslide deposits surface roughness-age function(t=1.47×10^(6)×e^(-1).46R,r2=0.63)that was used to estimate regional landslide ages in LX.We conclude that three periods with clusters of regional landslides in LX were revealed by different surface roughness of landslide deposits combing roughness-age function,with the values of 5563-7455 yr B.P.,1724-4151 yr B.P.,and 960-1287 yr B.P..Furthermore,we used our estimates of landslide ages to quantify landslide erosion rates of three corresponding hillslopes in LX ranging from 0.50 to 2.42 mm yr-1.Although rock varnish radiocarbon dating provides us a feasible option for timing regional landslides of arid regions,the epistemic uncertainty in the dating method should arouse our attention,which could be reduced by increasing the number of samples.

Genesis of the Sinongduo Carbonate-hosted Pb-Zn-Ag Deposit in the Central Lhasa Terrane,Tibet

The Sinongduo mining region includes two types of mineralizations:the epithermal and the carbonate-hosted PbZn-Ag deposits.Despite being studied for many years,the ore formation process and genesis of the carbonate-hosted Pb-Zn-Ag deposits remain poorly understood.The Pb-Zn-Ag ore bodies occur as veins and are hosted by limestone and dolostone of the Permian Xiala Formation.Three sulfide mineralization substages have been identified at the Sinongduo carbonatehosted deposit.Indium coupled with Cu,Co and Sn was incorporated into sphalerite as substitutions:2Zn^(2+)?Cu^(+)+In^(3+),(3n/2+1)Zn^(2+)?Co^(2+)+n In^(3+)or(2n+1)Zn^(2+)?Co^(2+)+n(Cu^(+)+In^(3+))(n>1)and 4Zn^(2+)?Sn2++2In^(3+).Sphalerite and pyrite in the mineralization stage displayδ^(34)S values in a narrow range of+5.7‰to+11.3‰,which are similar to those of Palaeocene igneous rocks,indicative of a magmatic source of sulfur.We present systematic carbon-hydrogen-oxygen isotope results that further support a magmatic source for the ore-forming fluids that were influenced by meteoric water.Furthermore,the Pb isotope compositions of sulfide minerals in the Sinongduo carbonate-hosted deposit overlap with the values of coeval Linzizong volcanic rocks and are similar to those of Indian Ocean sediments,indicating upper crustal sources of metals.We conclude that the Sinongduo carbonate-hosted Pb-Zn-Ag deposit is a medium-to low-temperature magmatic-hydrothermal deposit related to Linzizong magmatism.