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The Qinghai-Tibet Plateau (QTP) is an area with highly distinctive natural and socio-cultural characteristics. In recent years, the pastoral areas of northern Tibet have undergone a phase transition from nomadic to settled grazing, and the settlement system is in a stage of formation and evolution. Against the backdrop of China's new strategy of rural revitalization, conducting associated research on the evolution of the settlement system and the prospect of rural revitalization is of great significance for improving the living and working conditions of herdsmen in alpine pastoral areas and promoting sustainable development on the QTP. Using settlement patch data obtained by visual interpretation of high-definition remote sensing images, combined with field investigations, this paper explores the temporal and spatial evolution characteristics of the settlement system in Nagqu County, northern Tibet, summarizing its development status and existing problems from the perspective of factor-structure-function, and details the paths for rural revitalization on this basis. The results show the following: (1) Since 2005, the settlement system of Nagqu County has undergone a phase transition from concentrated settlement to functional expansion, with the continuous enrichment of development elements and the enhancement of functions. The density distribution of settlements shows strong adaptability to the natural geographical environment. The pattern of settlement has gradually changed from resource-dependent to facility-dependent. Transportation and public service facilities play an important role in guiding the speed and direction of settlement evolution. (2) There are still various problems in the settlement system of Nagqu County, including a weak industrial foundation; some occupation of important ecological spaces and ecologically fragile areas by settlements; insufficient attention to the cultural aspect of the Tibetan settlement system; a scattered settlement layout, which makes grassroots governance difficult; a large talent gap; and weak spatial support system of settlements. (3) From the perspective of enriching and integrating the development factors of rural settlements, reorganizing the diversified structure of rural settlements, and improving and expanding the functions of rural settlements, this paper explains the correlation mechanism between optimization of the rural settlement system and rural revitalization, and puts forward the implementation paths for rural revitalization in alpine pastoral areas of the QTP. The study expands our understanding of the characteristics of settlements in sparsely populated alpine pastoral areas, and provides valuable, up-to-date policy guidance for the promotion of rural revitalization in alpine pastoral areas on the QTP. [ABSTRACT FROM AUTHOR]

[Display omitted] • The land surface area of the mainland China was calculated based on 30 m resolution DEM. • Absolute difference and relative difference of ESV based on surface area and plane area was conducted at country, provincial and county levels. • The characteristics of temporal-spatial variation of ESV of various ecosystems based on surface area in China were revealed. • The total ESV based on surface area was compared with other studies. • The importance of the surface area in land resource survey, natural asset estimation and ecological protection was emphasized. The assessment of ecological assets is of great significance for protecting and using ecological resources. Traditional methods of ecological assets assessment, which adopt the planar area as the standard, often ignore the impact of the surface area, resulting in a large difference between the evaluation and the actual result. To fill this gap, this paper conducted research on ecological assets assessment based on surface area. Taking mainland China into consideration, this paper constructed a triangulation network based on 30 m resolution DEM data to simulate the real land surface form and calculate its surface area. Then, land use/cover data from 1995, 2000, 2005, 2010, and 2015 were used to estimate the ecosystem service value (ESV) and analyze its spatial variation. This paper found that: (1) The surface area of mainland China is 1.04 × 107 km2, which is 8.2 × 105 km2 larger than the planar area; (2) A huge difference was found between the total ESV based on the surface and planar area, with an absolute difference of ∼$141.66-$144.14 billion and a relative difference of ∼ 10%. For different ecosystem types, the largest difference was found in the forest ecosystem, followed by the grassland ecosystem, while the wetland ecosystem showed the smallest difference; (3) The high value of absolute difference between the ESV based on the surface and planar area was concentrated in Tibet and Northeast China. The high value of relative difference was mainly distributed in Central and Southern China. On the provincial level, the absolute difference in Tibet ranked in the first place. There was a total of 14 provinces showing a relative difference above 10%; (4) The total ESV based on surface area was basically unchanged, while various ecosystems underwent significant changes. The ESV of wetland increased by nearly 50%, while the ESV of grassland decreased by more than 10%; and (5) Change in the ESV based on surface area showed obvious spatial heterogeneity. High-High cluster was located in Tibet and the Northeast China while the Low-Low cluster was distributed in the North China Plain and Xinjiang. This paper emphasized the importance of the surface area in resource survey and asset estimation and gave more effective suggestions for ecological protection. [ABSTRACT FROM AUTHOR]

In the context of carbon neutrality, renewable energy, especially wind power, solar PV and hydropower, will become the most important power sources in the future low-carbon power system. Since wind power and solar PV are specifically intermittent and space-heterogeneity, an assessment of renewable energy potential considering the variability of wind power and solar PV with high temporal resolution in different regions will facilitate more accurate identification of the decarbonization pathway of power system. In this paper, the complementary output potential of wind-solar-hydro power every 15 min in 31 Chinese provinces is evaluated by developing a multi-objective optimization model based on Nondominated Sorting Genetic Algorithm II. The results show that the total annual complementary power generation potential in China is 17.57 PWh, of which the three components account for 47.8%, 25.3% and 26.9%, respectively. Inner Mongolia and Tibet are the major renewable energy source provinces with annual complementary power generation potential of 5330 TWh and 3907 TWh, accounting for 30.3% and 13.7% of the total power generation potential, respectively. The temporal potential of wind-solar-hydro power varies greatly, with daily potential is more volatile than monthly. Seasonal and spatial heterogeneity of the complemental renewable potential makes some provinces suffer power shortage during long-hours period especially in winter. Our findings will encourage a higher penetration of renewable energy, the promotion of multi-energy complementarity, and the development of inter-provincial power transmission and energy storage infrastructure in China's future power sector. • A multi-objective wind-solar-hydro complementary optimization model is developed. • Electricity supply and demand have gaps at different temporal and spatial scales. • Wind-solar-hydro complementary potential shows great temporal and spatial variation. • Renewable complementarity can improve China's future power system stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Depleted continental mantles occur with different mineral chemistry and occurrence. • Mafic dikes were formed from melts via low-degree melting of asthenosphere mantles. • Orthopyroxenites were formed from reaction between SiO 2 -rich melts and peridotites. • Ophiolites were formed in a continental margin that was related to the Meso-Tethys. Whether the ophiolites in the southeast margin of the Gaoligong tectonic belt are related to subduction or rift is hotly debated. The aim of this paper is to present the geological and geochemical data of these ophiolitic blocks in order to understand the significance of these in the tectonic evolution of the Meso–Tethys. The peridotites in the ophiolites are dominantly harzburgites with high Mg# (88.7–92.2) and low Al 2 O 3 (<0.8 wt%) and CaO (<0.5 wt%) contents, and display U-shape chondrite-normalized rare-earth element patterns. However, they show two different groups of mineral chemistries and occurrences. Group I are with olivine Fo 90.6–92.3, orthopyroxene Mg# 91.0–92.6, clinopyroxene Mg# 91.1–93.3, and spinel Cr# 42.1–67.4 and Mg# 62.8–71.6. They exhumed adiabatically and were intruded by mafic dikes from the melts through low-degree melting of asthenospheric mantles and by orthopyroxenites in the Early Jurassic. Group II are with olivine Fo 89.8–95.3, orthopyroxene Mg# 91.3–94.6, and spinel Cr# 62.4–94.1 and Mg# 19.5–51.0. They underwent brittle deformation and medium- to low-temperature fluid replacement. The two group's peridotites have experienced the similar partial melting degrees and are the fragments of subcontinental lithospheric mantles. Extensive continental affinity tholeiites erupted in the Middle Jurassic, coeval with the primary spreading time of the Bangonghu–Nujiang Ocean in the central Tibet. The peridotites, mafic rocks, and marine-facies sediments represent the opening products of the Meso–Tethys in the Jurassic as ophiolites in a continental margin. [ABSTRACT FROM AUTHOR]

• The ecohydraulic modeling framework is a valuable tool for assessing fish ecology in dammed rivers. • Cascade dam construction could fragment spawning site habitats and reduce fish population abundance in the tailwater zone of the main stream. • Spawning site habitats would improve, leading to an increase in fish population abundance in the backwater zone of tributaries. • The effects of cascade dam construction on endemic fish habitat and population status depend on spawning site location, fish species, and life stages. Cascade dam constructions will alter the habitat of spawning sites and affect fish population in the Lancang River basin. This paper examines the impacts of cascade dam construction on four spawning sites, focusing on two co-distributed and endemic fish species: Schizothorax prenanti and Schizothorax davidi. An ecohydraulic modeling framework that combined hydro-morphodynamic, habitat, and population models was used to investigate changes in habitat quality and fish population under two scenarios: no-dam and with-dam. Fish habitat quality was evaluated using the habitat suitability index, and population fluctuations were assessed by the abundance and density of fish populations at all life stages. The simulation results indicated that cascade dam construction would fragment the spawning site habitat in the tailwater zone of the main stream and result in a decrease in fish population abundance and density. Conversely, spawning site habitats in backwater zone of tributaries would improve, and fish population abundance and density would increase. Additionally, the simulation results showed that the magnitude of fish population variations varied by species and life stages. These results highlight the different responses of spawning site location, fish species, and life stages to dam construction, which can help identify areas of the habitat with higher potential for finer-scale endemic fish conservation and recovery efforts. This study provides a comprehensive framework tool for fish ecological evaluation in dammed rivers, which has the potential to assist decision-makers involved in river ecosystem ecological conservation. [Display omitted] [ABSTRACT FROM AUTHOR]

Summary This paper pursues an inquiry into the relationship between ethnicity and development in the largest authoritarian country in the contemporary world, the People’s Republic of China. It engages the theoretical literature on ethnic diversity and development in general, but also pays special attention to political economy logics unique to authoritarian systems. Focusing on the western part of China over a decade since the launch of China’s Western Development Program ( xibu da kaifa ) in 2000, this paper utilizes the data from two censuses (2000 and 2010) together with nighttime streetlight imagery data to analyze the overall relationship between ethnicity and development provision. It also analyzes changes in such a relationship during this period. The paper finds that ethnic minority concentration negatively correlates with economic development in both the years 2000 and 2010 across the western provinces. It also finds that counties in non-autonomous provinces, which are historically more integrated with the rest of China than autonomous provinces, have a positive and systematic correlation between changes in ethnic minority concentration and changes in development during the 10-year period. The counties in autonomous provinces, on the other hand, show the opposite trend. Using three case studies of Tibet, Inner Mongolia, and Xinjiang, the paper concludes that although there is in general a tendency for ethnic minority concentrated areas to be less developed, ultimately which groups prosper more or less depends upon specific economic development and which political control logics the Chinese state implements. [ABSTRACT FROM AUTHOR]

In this paper, we examine the Early to Middle Holocene evolution of a prominent group of ground-water fed lakes in the southeastern hinterland of the Badain Jaran Desert (BJD) of northwest China. Specifically, we describe a sediment profile record from the Taoerlegetu (TR) palaeolake basin using multiple proxies of total organic carbon (TOC), total nitrogen (TN), C/N ratio, δ13C org , grain size and mineral composition based on a well-dated trench profile. As C/N values suggest that sedimentary organic matter mainly originated from aquatic plants, δ13Corg values can be used as a qualitative proxy for water level because aquatic plants in different biotopes (water depth) have different δ13C values. Our results show that from 10.9 to 9.1 cal kyr B.P., water level rose slowly, and aquatic macrophytes occupied the lake basin. From 9.1 to 5.5 cal kyr B.P., water level reached an even higher level and phytoplankton replaced macrophytes as the major contributor to organic matter. The humid episode of the lakes in the hinterland of the BJD in the early Holocene might be related to the increased groundwater supply from the northeast region of the Tibet Plateau. These findings are consistent with earlier studies of lacustrine and peat sediments found in periphery of the modern lake group, which indicate that their geographic extent may have been larger in the past. A relative drought period recorded in the studied succession from 8.5 to 8.0 cal kyr B.P. marks an interval of reduced ground-water transport from the Tibet Plateau. This interval probably corresponds to the "8.2 ka cold event" and provides evidence that this widespread climate episode influenced groundwater processes across inland Asia. • The δ13C org value could be used as a qualitative indicator for the change of water level. • Lakes in the hinterland of the Badain Jaran Desert shows different evolution progress with these in the edge. • The main water source of lakes in the hinterland of the BJD in the Early Holocene comes from the Tibet Plateau. [ABSTRACT FROM AUTHOR]

Abstract: In order to improve living environment for the villages in Tibetan areas of Yunnan, this paper takes Shangri-La’s wooden architecture as research objects, analyses the site selection, plane layout, facade design, building materials and fabric detail of traditional rural housing by investigation. The paper also extracts the local inherent eco-technologies, and identifies the shortcomings of rural housing. Aimed at the flawed characteristics of Tibetan building such as the scattered building location, high Shape coefficient, less–story, poor insulation, massive energy consumption and redundant land occupation, this paper researches adaptable design strategies of green rural housing which is suitable to local condition, so as to boost the sustainable development of rural construction of Tibetan areas in Yunnan. [Copyright &y& Elsevier]

Ethnopharmacological relevance Aquilaria spp. (agarwood) has been a part of Ayurvedic and Traditional Chinese Medicine for centuries. Agarwood has also been used as a traditional medicine in Southeast Asian countries, Bangladesh and Tibet. Its common uses include the treatment of joint pain, inflammatory-related ailments, and diarrhoea, as well as a stimulant, sedative and cardioprotective agent. In this paper, we aim to provide an overview of the phytochemistry, ethnomedicinal use, pharmacological activities and safety of plant materials from Aquilaria spp. as an evidence base to further appraise its potential use as a source of health beneficial compounds. Materials and methods Literature abstracts and full text articles from journals, books, reports and electronic searches (Google Scholar, Elsevier, PubMed, Read Cube, Scopus, Springer, and Web of Science), as well as from other relevant websites, are surveyed, analysed and included in this review. Results A literature survey of agarwood plant materials showed that they contain sesquiterpenes, 2(-2-phenylethyl)-4H-chromen-4-one derivatives, genkwanins, mangiferins, iriflophenones, cucurbitacins, terpenoids and phenolic acids. The crude extracts and some of the isolated compounds exhibit anti-allergic, anti-inflammatory, anti-diabetic, anti-cancer, anti-oxidant, anti-ischemic, anti-microbial, hepatoprotective, laxative, and mosquitocidal properties and effects on the central nervous system. Agarwood plant materials are considered to be safe based on the doses tested. However, the toxicity and safety of the materials, including the smoke from agarwood incense burning, should be further investigated. Future research should be directed towards the bio-guided isolation of bioactive compounds with proper chemical characterisation and investigations of the underlying mechanisms towards drug discovery. Conclusions The traditional medicinal use of agarwood plant materials has provided clues to their pharmacological properties. Indeed, agarwood contains a plethora of bioactive compounds that now elegantly support their use in traditional medicine. As wild agarwood trees are critically endangered and vulnerable, sustainable agricultural and forestry practices are necessary for the further development and utilization of agarwood as a source of health beneficial compounds. [ABSTRACT FROM AUTHOR]

Based on ethnographic research on exiled Tibetan political institutions and practices in India, this paper investigates sovereignty in exile. The Tibetan Government-in-Exile (TGiE) remains internationally unrecognised and lacks de jure sovereignty over territory in both Tibet and in exile. However, this exiled administration claims legitimacy as the official representative of the Tibetan population, performs a number of state-like functions in relation to its diasporic ‘citizenry’ and attempts to make its voice heard within the international community. Rejecting arguments that such entities should be viewed merely as discrepant forms of political practice, this paper asserts that the state, sovereignty, and territory can be conceptually disentangled, opening up the theoretical possibility of entities other than territorial states claiming sovereignty. In teasing apart and problematising constituent elements of sovereignty, this paper focuses on three aspects of the TGiE's articulations of sovereignty: its claims to and production of legitimacy, authority and de facto sovereignty; its displaced sovereignty and strategies of territorial governance over non-contiguous spaces in exile; and the mediation of its ambiguous relationship with the host state India through practices of tacit sovereignty. [Copyright &y& Elsevier]

An in situ test was conducted to investigate the short-term mechanical behavior of frozen soils along the Qinghai–Tibet Highway, in China, using the pressuremeter. This paper uses the plane elasticity theory and the radial expansion equation of cylindrical hole in infinite elastic medium provided by Lame´ to interpret the test data. The initial horizontal pressure, the critical plastic load and the limit pressure are reduced from the pressuremeter testing curves, and then, the pressuremeter modulus and the shear modulus are worked out. This paper also analyses the relationships between the mechanical parameters and the soil temperature and the water contents, respectively, and gives out the approximate formula. At the same time, some inevitable problems encountered during the operating of test are discussed. [Copyright &y& Elsevier]

With the great successes in improving rural electrification and reducing poverty, China's small hydropower (SHP) development is expected to provide a good example for other developing countries. However, recently, nearly all new SHP development plans have been halted, and many plants have been urged to shut down or even be removed. The SHP industry in China is now in a dilemma. This paper presents a review of the status of SHP development in China and explores the challenges troubling this industry. It was revealed that SHP resources in many provinces have been intensively exploited, with an exploration rate over 0.80, while untapped resources are primarily located in remote western provinces, such as ecologically fragile Tibet. This intensive and disordered SHP development has caused serious dewatering of rivers and affected local agricultural and household water access, which arouses fierce controversy. Moreover, the role of SHP has been gradually weakened by the extension of power grids and diversified electricity sources. Therefore, the transition and upgrade of the SHP industry has become critical to enhance its sustainable development and to provide a solid example for the world. A divergence management strategy for SHP should be adopted to achieve low-impact development, as opposed to blind large-scale development or rigidly discontinuing all projects. Future transition strategies are proposed in this paper that include delicate management of existing plants and construction of new plants with higher standards, as well as pathways for the development benefits to be shared by a wider range of local residents. • This study investigated the history and status quo of SHP development in China. • SHP resources in most provinces are intensively developed except some western areas. • Growing challenges that trouble the SHP industry in China were identified. • Future transition strategies for the SHP industry in China were proposed. [ABSTRACT FROM AUTHOR]

This paper quantitatively measures the labor productivity dispersion index of 30 provincial-level political regions (excluding Tibet) in mainland China from 2006 to 2018 based on industrial employment and output share data. Based on clarifying each region's economic variability, a spatial panel model is used to examine regional economic growth and labor productivity dispersions' effects on energy intensity. It was found that energy intensity in China is significantly spatially correlated. There is a clear gap between the share of output and the share of employment in China's three industries where labor productivity has deviated. The highest index of labor productivity dispersion is found in the western region, followed by the central region, with the lowest in the eastern region. Although, China's economic growth has had a significant negative impact on energy intensity, the current stage of China's economic development model is able to gradually achieve efficient energy use. However, the dispersion of labor productivity is not conducive to the improvement of energy factor allocation efficiency, and rationalization of industrial structure and employment structure transformation are urgently needed. To control energy intensity, China should actively adjust the current labor productivity dispersion; promote the transfer of primary industry labor to secondary and tertiary industries; strengthen control mechanisms for energy prices; optimize the impact of investment activities on energy intensity; and improve energy efficiency. • China's factor input structure and power sources are undergoing profound changes. • The study incorporates spatial measures to study the energy intensity problem. • Labor productivity dispersion raises energy intensity. • Economic growth is decoupled from energy intensity at this stage. • Higher energy prices can actually lead to higher energy intensity. [ABSTRACT FROM AUTHOR]

The Silurian conodont biozonation has been well established in many areas of the world, but not yet in China. The Nyalam region of southern Xizang (Tibet) is one of the best locations for studying Silurian conodonts in China. In this paper, we establish five conodont biozonal units from the Pulu Formation: the Ozarkodina sagitta sagitta Biozone, the Kockelella crassa Biozone, the Kockelella variabilis variabilis – Ancoradella ploeckensis Zonal Group, the Polygnathoides siluricus Biozone, and the " Ozarkodina " eosteinhornensis s.l. interval Biozone. We assign the Pulu Formation to the Llandovery (upper Telychian) to Pridoli stages based on the conodonts as well as the graptolites from underlying strata. The Silurian conodont species in the Nyalam region are widely distributed in the strata from the Laurussia and Gondwana, which indicates the cosmopolitan characteristic of the conodont fauna from the Wenlock to Pridoli epochs was caused by the circulation of ocean currents. • Five conodont biozonal units from Wenlock to Pridoli were identified in the Nyalam region. • Pulu Formation in the Nyalam region is Telychian to Pridoli in age. • Silurian conodont fauna in the Nyalam region have a cosmopolitan characteristic. [ABSTRACT FROM AUTHOR]

• The thermal decomposition of marine carbonates and metasediments is a source of CO 2. • The radioactive decay of U and Th within crustal granite is the dominant source of He. • Three thermal reservoirs were identified using multiple gas geothermometers. • The parent geothermal fluid had a temperature of ∼320 °C at an ∼8-km depth. • Yangbajing has no supercritical fluids, given its small, deep-seated magma chamber. Exploring and exploiting high-temperature (even supercritical) geothermal resources are significant to meet energy demands and reduce carbon emissions. The Yangbajing geothermal field is the most exploited in China, with the currently highest temperature (329.8 °C) measured in a geothermal well. However, whether there are supercritical geothermal fluids beneath the deep parts of this geothermal field is under controversy. In this paper, the water isotope, chemical compositions, and C–He isotopes of gas samples were collected and analyzed. The geothermal water originated from the mixing of meteoric water and magmatic water (25%). The sources of CO 2 in the geothermal field were dominated by the thermogenic degassing of carbonates and metasediments in the crust while the radioactive decay of U and Th in granite is the dominated source of He. The temperatures of three different reservoirs are 150 ± 15 °C, 250 ± 10 °C, and ∼320 °C (with a depth of ∼8 km), respectively. These were obtained using dissolved gas, soil CO 2 flux, and noble gas geothermometers. Unlike other supercritical geothermal fields worldwide with larger, shallower, basaltic magma chambers, the Yangbajing geothermal field has a deep-seated, small-scale, granitic magma chamber. Thus, its geological conditions are not conducive for gestating supercritical fluids. These results are of great significance for exploring and developing high-temperature (even ultra-high-temperature) geothermal resources in China. [ABSTRACT FROM AUTHOR]

The gross primary production (GPP) at individual CO 2 eddy covariance flux tower sites (GPP Tower ) in Dali (DL), Wenjiang (WJ) and Linzhi (LZ) around the southeastern Tibetan Plateau were determined by the net ecosystem exchange of CO 2 (NEE) and ecosystem respiration ( R e ). The satellite remote sensing-VPM model estimates of GPP values (GPP MODIS ) used the satellite-derived 8-day surface reflectance product (MOD09A1), including satellite-derived enhanced vegetation index (EVI) and land surface water index (LSWI). In this paper, we assembled a subset of flux tower data at these three sites to calibrate and test satellite-VPM model estimated GPP MODIS , and introduced the satellite data and site-level environmental factors to develop four new assimilation models. The new assimilation models’ estimates of GPP values were compared with GPP MODIS and GPP Tower , and the final optimum model among the four assimilation models was determined and used to calibrate GPP MODIS . The results showed that GPP MODIS had similar temporal variations to the GPP Tower , but GPP MODlS were commonly higher in absolute magnitude than GPP Tower with relative error (RE) about 58.85%. While, the assimilation models’ estimates of GPP values (GPP MODEL ) were much more closer to GPP Tower with RE approximately 6.98%, indicating that the capacity of the simulation in the new assimilation model was greatly improved, the R 2 and root mean square error (RMSE) of the new assimilation model were 0.57–4.90% higher and 0.74–2.47 g C m −2 s −1 lower than those of the GPP MODIS , respectively. The assimilation model was used to predicted GPP dynamics around the Tibetan Plateau and showed a reliable result compared with other researches. This study demonstrated the potential of the new assimilation model for estimating GPP around the Tibetan Plateau and the performances of site-level biophysical parameters in related to satellite-VPM model GPP. [ABSTRACT FROM AUTHOR]

Abstract: The 2008 Mw 7.9 Wenchuan earthquake is a consequence of ongoing India-Tibet collision and reflects the growth of the Longmen Shan fold-and-thrust belt. In this paper, we present new constraints on the deformation mechanism of the Longmen Shan fold-and-thrust belt, by comparing the physical models to the example of the Longmen Shan fold-and-thrust belt. The result indicates that the deformation mechanism of the belt is mainly dominated by the pre-Sinian layer, whereas locally is controlled by the Lower Triassic layer, such as the Longquan anticline. In addition, we discuss the deformation style of the Longquan anticline various along strike, based on the seismic reflection data, interpretations of structural cross-sections and field observations, as well as physical modeling. The sandbox modeling suggests that the deformation of the central segment of Longquan anticline is likely controlled by higher displacement rate, higher erosion and lower sedimentation, which is in contrast with the southern and northern segment. Moreover, the structural geometry of the central segment of Longquan anticline is more complex than the end-member models of fault-related folds, which is mainly controlled by pure-shear wedge fault-bend fold and bounded by west-verging thrust fault. Combining the studies of the structural geometry, deformation mechanism, and previous studies, we infer that the Longquan anticline is active and potentially seismogenic. Therefore, a quantitative re-evaluation of seismic hazard in Longquan anticline and adjacent area directly beneath the densely populated Sichuan basin is urgently needed. [Copyright &y& Elsevier]

Abstract: Powerful forces of agrarian change are at work in western China while the government has stepped up efforts to “modernize” agriculture. Major components of the modernization process are to disseminate improved crop and livestock breeds and adjust changing agricultural structures including a shift from staple food crops to more specialized crop-livestock systems. This paper explores the changing role of agriculture and the impacts of new agricultural structures on household livelihoods through a detailed model of farm households. The model aids understanding of the complex dynamics and choices faced by farm households that consume much of their own food production but who are under great pressure to specialize and engage in more commercial activities both on- and off-farm. The model draws on detailed information and case studies in Tibet, a region that reflects the marginal productivity, ethnic diversity, rudimentary market systems and development challenges of much of western China. The model results demonstrate that even in the context of agrarian change, agriculture continues to play a significant role in the livelihoods of these Tibetan farm households. They also highlight how mooted specialization paths, despite significantly increasing household returns, fundamentally change the nature of these farm and household systems and risks faced by these households. The detailed modelling enables identification of tight labour constraints, feed gaps and other changes to farm and household systems brought about by the specialization. Such information is crucial in guiding refinements to marketing systems and institutional and policy settings needed to strengthen and smooth out the process of agrarian transition in western China. [Copyright &y& Elsevier]

Summary: Alpine meadow soil is an important ecosystem component of the Qinghai-Tibetan Plateau. However, the alpine meadow soil is undergoing serious degradation mainly due to global climate change, overgrazing, human activities and rodents. In this paper, spatial sequencing was chosen over time succession sequencing to study the changes of soil hydraulic properties under different degrees of alpine meadow degradation. Soil saturated hydraulic conductivity (Ks) and Gardner α both at the surface and at 40–50cm depth were investigated in the field using tension infiltrometers. Soil physical and chemical properties, together with the root index at 0–10cm and 40–50cm soil layer depths were also analyzed. Pearson correlations were adopted to study the relationships among the investigated factors and principal component analysis was performed to identify the dominant factor. Results show that with increasing degree of degradation, soil sand content increased while soil Ks and Gardner α as well as soil clay content, soil porosity decreased in the 0–10cm soil layers, and organic matter and root gravimetric density decreased in both the 0–10cm and 40–50cm soil layers. However, soil moisture showed no significant changes with increasing degradation. With decreasing pressure head, soil unsaturated hydraulic conductivity reduced more slowly under degraded conditions than non-degraded conditions. Soil Ks and Gardner α were significantly correlated (P =0.01) with bulk density, soil porosity, soil organic matter and root gravimetric density. Among these, soil porosity is the dominant factor explaining about 90% of the variability in total infiltration flow. Under non-degraded conditions, the infiltration flow principally depended on the presence of macropores. With increasing degree of degradation, soil macropores quickly changed to mesopores or micropores. The proportion of total infiltration flow through macropores and mesopores significantly decreased with the most substantial decrease observed for the macropores in the 0–10cm soil layer. The substantial decrease of macropores caused a cut in soil moisture and hydraulic conductivity. This study improves the understanding and prediction of alpine meadow soil and ecosystem changes and provides guidelines for improving water flow modeling under the background of global climate change over the Qinghai-Tibetan Plateau and similar regions. [Copyright &y& Elsevier]

Abstract: ARGO-YBJ is a multipurpose experiment consisting in a dense sampling air shower array with 93% sensitive area located at very high altitude. The apparatus is in stable data taking since November 2007 at the YangBaJing Cosmic Ray Laboratory (Tibet, PR China, 4300ma.s.l., 606g/cm2). In this paper we report the main results in Gamma-Ray Astronomy and Cosmic Ray Physics after about 3years of operation. [Copyright &y& Elsevier]

Abstract: This paper reports new zircon LA-ICP-MS U–Pb age and Hf-isotope, whole-rock major and trace element, and Sr–Nd isotope data from Cambrian metavolcanic rocks in the central Lhasa subterrane of southern Tibet. These rocks form a bimodal volcanic suite consisting mainly of silicic metavolcanic rocks with subordinate metabasalts. Five silicic metavolcanic samples dated at ca. 492Ma and one metabasalt sample yielding a near-concordant 206Pb/238U age of 492±4Ma indicate that mafic and silicic eruptions were contemporaneous. The metabasalts are mostly high-K calc-alkaline, enriched in Th, U, and light rare earth elements (LREEs), and depleted in Nb, Ta, Ti, Zr, and Hf, geochemically resembling the Andean arc basalts. The silicic metavolcanic rocks are high-K calc-alkaline and low in Nb and Zr. The metabasaltic rocks have negative whole-rock εNd(t) values (−4.7 to −3.5) and varying zircon εHf(t) values (−0.7 to +7.5), differing significantly from those of the silicic metavolcanic rocks, which yield negative whole-rock εNd(t) values of −8.4 to −7.2 and varying zircon εHf(t) values (−13.9 to −4.6). The metabasaltic rocks are interpreted as resulting from partial melting of an enriched lithospheric mantle source that was metasomatized by subduction-related components, whereas the silicic metavolcanic rocks were derived from basaltic melt-induced anatexis of the ancient Lhasa basement with inherited mantle melt signatures. The Western Qiangtang–Amdo–Tethyan Himalaya situated in the Indian proto-Tethyan margin and the Lhasa and other possible microcontinents or terranes (e.g., Gongshan, Baoshan, Tengchong, Burma, and Sibumasu) paleographically located in the Australian proto-Tethyan margin represent an early Paleozoic Andean-type magmatic arc facing the proto-Tethyan Ocean. The emplacement of the bimodal volcanic rocks and the development of the Cambro–Ordovician angular unconformity in the central Lhasa subterrane can be attributed to slab break-off of the proto-Tethyan Ocean lithosphere following the collisional accretion of microcontinents or terranes located outboard of the magmatic arc (possibly Eastern Qiangtang and South China). [Copyright &y& Elsevier]

Abstract: The Lhasa terrane, southern Tibet is where the thickest part of the Earth’s crust occurs as a result of the India–Asia collision. This paper reports zircon U–Pb age and geochemical data of samples collected from the Gangdese batholith, southern Lhasa terrane, a subset of which has already been dated at 65–41Ma using zircon U–Pb geochronology (Ji, W.Q., Wu, F.Y., Chung, S.L., Li, J.X., Liu, C.Z., 2009a. Zircon U–Pb chronology and Hf isotopic constraints on the petrogenesis of Gangdese batholiths, southern Tibet. Chemical Geology 262, 229–245), to constrain the timing and mechanism(s) responsible for crustal thickening beneath southern Tibet. Our new data indicate that the Gangdese magmatism lasted continuously from ca. 65 to 34Ma, during which geochemical evidence for crustal thickening is observed. Crustal thickening is best illustrated by the progressive increase in La/Yb and Sr/Y of the Early to latest Eocene magmatic rocks, associated with the decrease in Hf isotopic ratios of Paleocene to Eocene magmatic zircons. We also identify in this study the oldest (ca. 51Ma), “post-collisional” adakitic granitoids in the Gangdese batholith, interpreted as products from partial melting of underplated basaltic lower crust. Therefore, a thickened crust likely existed by that time, at least locally, in the southern Lhasa terrane, Tibet. [Copyright &y& Elsevier]

Abstract: Despite more than 30 years’ studies in the Yarlung Zangbo Suture Zone (YZSZ), southern Tibet is still a region of discovery and the geological evolution of the Neo-Tethys here remains controversial. In this paper we present the new field observation, petrography, zircon U–Pb dating and geochemistry of the Zhongba mafic rocks in the western segment of the YZSZ. Zircon U–Pb analyses from a diabase using SIMS (Secondary Ion Mass Spectrometry) yielded a concordant age of 125.7±0.9Ma. All the Zhongba mafic rocks exhibit LREE enrichment (LaN/YbN =4.7–15.8) without Eu anomalies (δEu=0.97–1.01). Their Primitive-Mantle-normalized trace element patterns are similar to those of the average OIB and Hawaii alkaline basalts, as well as other OIB-type rocks already reported in the central-western YZSZ. These observations lead us to suggest the existence of a series of seamounts within the Neo-Tethys during the Early Cretaceous. These OIB-type rocks could be originated from (1) hotspot mantle; (2) near-ridge seamounts by melting-induced mixing of two distinct mantle sources; (3) late-stage magmatism fed by melts that originated from an asthenospheric window due to slab delamination. Combining literature data from the entire YZSZ, which include studies of the MORB- and IAB-type rocks and mantle peridotites, we prefer the third explanation that the OIB-type rocks represent a late-stage magmatic activity above an intra-oceanic supra-subduction zone within the Neo-Tethys. [Copyright &y& Elsevier]

Abstract: The Tibetan plateau contains thousands of small and big lakes. Changes in the water level of these lakes can be an important indicator for the water balance of the Tibetan plateau, but were until now extremely difficult to monitor: performing continuous in situ measurements at a large number of lakes is not feasible because of their remoteness, while radar altimetry is only capable of monitoring large lakes. Between 2003 and 2009 the Geoscience Laser Altimeter System (GLAS) on board of the Ice, Cloud and land Elevation Satellite (ICESat) obtained world-wide elevation profiles during 18 one-month campaigns. Using the GLAS data it is possible to obtain lake levels at decimeter accuracy. Available GLAS data over the Tibetan lakes is selected by means of the MODIS lake mask. As a result, lake level variations between 2003 and 2009 of 154 lakes of over a square kilometer size could be observed. For these lakes, an analysis of annual water level trends is made, and then their yearly gained or lost water volumes are estimated. In total, an area averaged increase in lake level of 0.20m/year over the Tibetan plateau is observed between 2003 and 2009. Most of the individual lakes considered in this paper have little or no levels apparently documented, and so the ICESat data provide the first baseline measurements of these lakes in the vertical. [Copyright &y& Elsevier]

Abstract: Carbonate minerals, oxygen and carbon isotopes, and Mg/Ca from surface sediments and soils were examined in Nam Co Lake, Central Tibet. This paper provides information of the irregular distribution and formation of monohydrocalcite, a metastable mineral. Carbonates of soils surrounding Nam Co Lake consist of calcite with minor dolomite. Carbonates in surface sediments in Nam Co Lake consist mainly of calcite and monohydrocalcite. All of the monohydrocalcite and most of the calcite in surface sediments are authigenic. The monohydrocalcite is distributed irregularly in Nam Co Lake because of inhomogeneous features of lake water, the variable micro-environment, high precipitation rate, and/or nucleation. Mg ions could play a greater role in the precipitation of monohydrocalcite than that of phosphate ions, because the amount of phosphate ions could be much lower than Mg ions in the 4781 m-altitude altiplano lake with poor nutrients. The presence of monohydrocalcite occurs at 2.1 ka BP, corresponding with the sharp increase of precipitation rate from 0.134 mm/y to 1.639 mm/y. High precipitation rate and/or nucleation is necessary for water molecule infiltration into the crystal lattice of monohydrocalcite. The δ18OV-PDB and δ13CV-PDB of carbonate minerals mixed with calcite and monohydrocalcite range from −5.3‰ to −8.0‰ with an average of −6.5‰, and from 2.8‰ to 4.5‰ with an average of 3.73‰, respectively. δ18OV-PDB and δ13CV-PDB of calcite range from −8.0‰ to −10.6‰ with an average of −8.09‰, and from 2.8‰ to 4.2‰ with an average of 3.25‰, respectively. Monohydrocalcite possibly has more positive values of δ18O and δ13C than those of calcite. [Copyright &y& Elsevier]

Abstract: There are still more than 30% of the Tibetan administrative villages without power, and about 40% farmers there are suffering from a serious shortage of firewood. Tibet is abundant in the deposits of hydropower, geothermal, and solar energy. The practical ways to solve the universal service of Tibetan rural energy are researched in the paper. We find that there are two main objectives of the universal access to energy in Tibetan rural areas. One is to meet the demand of electricity consumption and daily energy consumption of the farmers and herdsmen without power, initially solve energy poverty, realize the equitable access to energy, and ensure the early access to modern civilization. The other is to guarantee the provision of energy required in Tibet''s rural economic development and urbanization. Their accomplishment depends on the responsibilities’ definition and implementation in the universal service of energy by the central and local governments, and on the establishment of a universal service mechanism of energy. The conflict between the need of energy development in the agricultural and pastoral areas of Tibet and its insufficient financial resources cannot be solved without the support and assistance from the central government and other developed provinces in China. [Copyright &y& Elsevier]

Abstract: The Xianshuihe–Xiaojiang fault zone (XFZ) forms a prominent linear NW–SE trending tectonic feature along the southeastern margin of the Tibetan Plateau. The spatial and temporal evolution of the predominantly strike–slip movement along the fault remains unclear, as estimates for the initiation age of its different segments range from 5 to 13Ma. The Jinhe–Qinghe fault (JqF; the south part of the Longmen Shan thrust belt) provides a key for understanding the tectonic role and deformation history of the Xianshuihe–Xiaojiang fault zone in terms of timing, magnitude of displacement, and spatial–temporal evolution. This paper presents research on the structure and chronology of the JqF. The results of a geometric and kinematic study of the Jinhe–Qinghe fault show it to be a thrust fault with a left-lateral strike slip component; The strike slip offset extends at least 13–18km to southwest, based on the shortening of its folds and faulting, and based on stream deflection. Ten apatite fission track apparent ages show a pronounced change in age/elevation gradient at ~17±2Ma, consistent with an abrupt increase of exhumation due to uplift of the hanging wall of the JqF at that time. Combined with the age of deformed Tertiary strata in the footwall of the JqF and the geometric relationships of the JqF with the Chenghai fault and the XFZ, this indicates that the JqF was active between 17 and 5Ma. Based on the fault chronology, geometry, and movement, we suggest that the fault was a transpressional structure at the south end of the XFZ during the period from 17 to 5Ma. [Copyright &y& Elsevier]

Abstract: The aim of this paper is to investigate the morphological implications of the interplay between tectonic movements at different rates, timescales, and spatial extent in a catchment of intermediate size, the Huang Shui River (a main tributary of the Yellow River in the NE Tibet Plateau). River incision started from a peneplain-like surface that developed in post-Miocene–Pliocene times. At the end of the Tertiary, a general tectonic uplift of the Tibetan Plateau initiated river incision. This general uplift also caused local fragmentation of the Huang Shui catchment into blocks (kilometers or maximally, a few tens of kilometers) of local extent that have subsided and/or uplifted relative to one another. Fluvial deposition of >30m in the subsiding blocks contrasts with erosion and formation of gorges in the uplifted blocks. Incision into the former peneplain was not continuous but a staircase of terraces developed under climatic influences. Terrace deposits are sometimes capped by interglacial soils or soil-derived material. Apparently, terrace incision occurred at the transition to the next cold period. The different rates of uplift and subsidence of the individual blocks resulted in the simultaneous development of erosion and accumulation terraces of different sizes within the same catchment, even within the same tectonic block. This makes it impossible to connect the terraces of the different blocks, except for the three youngest terraces (representing the last 300,000years), thus illustrating the uniform tectonic history of the catchment since that time. [Copyright &y& Elsevier]

Abstract: A ∼500km-long high-pressure metamorphic belt occurs in the Qiangtang Block of northern Tibet. The occurrence of high-pressure metamorphic rocks (eclogite and blueschist) has a significant bearing on the Paleo-Tethys subduction and plate suturing processes. A few studies have been conducted on petrology, mineralogy and geochronology of high-pressure rocks. In this paper we present the results of a geochemical and isotopic investigation on eclogite and blueschist from this belt, and discuss the probable geodynamic implications. Geochemical analyses show that the two rock types, eclogite and blueschist, have grossly similar bulk compositions, but they can be subdivided into two groups based on their TiO2 contents. The low TiO2 (<2.75wt.%) rocks exhibit REE distribution patterns and trace element abundances similar to enriched mid-ocean ridge basalts (E-MORB), whereas the high TiO2 (>2.75wt.%) rocks are more akin to ocean island basalts (OIB). The positive ε Nd(T) values (ranging from 0.4 to 6.3) for all samples suggest that the basaltic protoliths of the eclogites and blueschists were derived from a long-term depleted mantle source. However, their geochemical characteristics require that the source be metasomatized and enriched in large-ion-lithophile and light rare-earth elements shortly before the formation of these basaltic protoliths, like for most OIB and E-MORB of the world. The recognition of oceanic basalts suggests that a Paleozoic ocean should be present in the central Qiangtang Block. This ocean was hypothesized to be the western extension of the Changning–Menglian Paleo-Tethys Ocean in the eastern margin of the Tibetan plateau. The eclogite and blueschist were formed by northward subduction of this Paleozoic ocean in the Triassic. [Copyright &y& Elsevier]

Abstract: This paper presents the first detailed investigation on airborne trace metals and their potential major sources at Lhasa, the largest city in Tibetan Plateau (TP). The whole year PM10 samples were collected during September 2007 and August 2008. The annual average concentration of PM10 in Lhasa was 51.8±42.5μgm−3, lower than those of major Asian cities. Distinct seasonal patterns were observed in PM10 concentration, with higher concentrations in winter, and lower in summer. The mean elemental concentrations were generally comparable with other urban areas, but significantly higher than those from a remote site in TP (i.e., Nam Co). Crustal elements, including Na, Mg, Al, K, Ca, Sc, Ti, V, Mn, Fe, As and Ba, had similar seasonal patterns in PM10, while other elements, such as Cr, Co, Ni, Cu, Zn, and Cd, had less distinct seasonal variations, suggesting more anthropogenic inputs of the latter group. The result of principle component analysis (PCA) on trace elements demonstrated that fugitive dusts, traffic emissions and waste incineration activities were probably the major sources of anthropogenic metals in the atmosphere at Lhasa. The Pb isotopic compositions revealed that the metal was mainly originated from nature background with a minor contribution from the cement factory. The data obtained in this study can be useful for making pollution control strategies in the city, and also valuable for trace element studies in other environmental medium, such as snow, ice core, and lake sediments in the TP region. [Copyright &y& Elsevier]

Abstract: The Gangdese Belt is now recognized as an important Cu polymetallic mineralization belt. Recent studies suggest that apart from porphyry copper deposits, polymetallic skarn deposits are another significant deposit type in this belt. In this paper, principal component analysis (PCA) and spectrum–area (S–A) fractal modeling are used to identify geochemical anomalies associated with Cu and Pb–Zn skarn mineralization based on Cu, Pb, Zn and Ag stream sediment data. Firstly, the raster maps of Cu, Pb, Zn and Ag were obtained by multifractal inverse distance weighted (MIDW). Secondly, PCA was used to combine the Cu, Pb, Zn and Ag concentration values. Finally, S–A analysis was used to decompose the first component pattern obtained by the PCA. The results show that major anomalies of Cu, Pb, Zn and Ag are mostly located around mapped intrusions, and along E–W trending faults, where Cu and Pb–Zn skarn deposits favorably occur. These results indicate that: (1) the Gangdese Belt potentially hosts undiscovered Cu and Pb–Zn skarn deposits, and the integrated anomalies for Cu, Pb, Zn and Ag occurring around the intrusions and in the vicinity of faults in the center part of the Gangdese Belt should be further investigated in the next step of mineral resource exploration; and (2) the hybrid method combining PCA and S–A modeling is an effective tool to identify geochemical anomalies. [Copyright &y& Elsevier]

Abstract: In this paper, the 3D Finite Element Method was combined with a Discontinuous Deformation Analysis (DDA+FEM) to study the influence of the Wenchuan earthquake on the stability of the tectonic blocks system of the Qinghai–Tibet Plateau under the background of northward extrusion of the Indian Plate and obstruction of the strong crust of the Sichuan basin. With constraints from GPS data and focal mechanisms, we first calculated the velocity and stress fields of the region. Then, we numerically simulated the rupture process of the seismogenic fault of the 2008 Wenchuan earthquake in overthrust form with a right-lateral component. We then studied the movement and deformation of the tectonic blocks that was caused by the earthquake and its influence on the stress state of the boundary faults. The numerical simulation indicates that the large earthquake causes the most tectonic blocks in the study zone at approximately a 1-mm deviation toward the northeast; in particular, the Wenchuan seismogenic fault obviously deviated eastwards, and the maximum deviation reaches 1.5m. It seems that the large earthquake causes the Bayankala block at the west side of the Longmenshan fracture zone to extend farther eastward. The Wenchuan earthquake causes the Coulomb failure stresses on the boundary faults of the tectonic blocks in the study zone to change to different extents. The maximum change of the Coulomb failure stress reaches about 0.2MPa at both ends of the Wenchuan seismogenic fault, the south section of the Xianshuihe fracture zone and part of the southeast section of the Dongkunlun fracture zone in the upper crust. Additionally, the Coulomb failure stresses also increase to different extents between 0.01 and .02MPa in regions such as the southernmost end of the Xianshuihe fracture zone, part of the southeast section of the Dongkunlun fracture zone, and so on. [Copyright &y& Elsevier]

Abstract: The fire signals are much weaker in low oxygen concentration and low pressure environment such as Tibet. Fire detectors which were calibrated in correlating standard conditions cannot work well in such condition. This paper presents a synthesis method of GM(1,1) grey prediction model and adaptive neuro-fuzzy inference system (ANFIS) in advance to detect fire and to make it work in the environment. The theoretical analysis of the algorithm and experimental evaluation in Tibet are presented. In this process, the grey GM(1,1) predict model can anticipate the development of fire signals without any assumption, thus allowing earlier fire alarm than traditional fire detection equipments, meanwhile, ANFIS can make sure the data processing more accurate to avoid false alarms. This work will supply useful suggestions with the fire detectors design in low ambient pressure and low oxygen concentration such as Tibet, etc. [Copyright &y& Elsevier]

Abstract: This paper reports that three earthquake sequence occurred in 1996 (m b 5.9), 1998 (m b 5.8) and 2004–2005 (m b 6.2, 6.3) were observed preceding the anomalous seismic activity. The nature of anomalous seismicity associated with these earthquakes have been investigated considering earthquakes with m b ⩾4.1 (cut off magnitude for this region) in four seismic episodes (NAGM): normal/background (N); anomalous/swarm (A); precursory gap (G) and mainshock sequence (M), respectively. It is established here that the anomalous seismicity/swarm patterns follow episodes of relatively very low seismic activity and it is an important finding to visualize that an area might be preparing for the occurrence of a forthcoming mainshock. Such anomalous seismic patterns were observed prior to medium size mainshocks that occurred from 1963 to 2006 in South Central Tibet (SCT) region to the north of Central Himalaya. From these observations it may be inferred here that the patterns of anomalous seismicity/earthquake swarms may be considered as an important parameter (precursor) for the forecasting of long-range earthquake hazards in the SCT region. In consideration of spatial and the temporal clustering of swarm events that are prominent and confined in a vertical column of 10–45km, enabled to locate potential area enclosed by 29.6–30.1°N and 87.8–88.1°E where future earthquake of magnitude 6.0 and above in the depth range 25±15km may be seated. In view of this multi-parameter short term precursory signals monitoring is suggested for the delineated preparatory area to make earthquake prediction/forecasting programs more meaningful. [Copyright &y& Elsevier]

Abstract: Long-term high-resolution climate proxies are essential for understanding climate variability on the Tibetan Plateau (TP), where few long-term climate records are available. In this paper, we describe a summer (August) temperature reconstruction over the period 1385–2002 based on a tree-ring width chronology of Balfour spruce (Picea likiangensis var. balfouriana) on the southeastern TP created using the Regional Curve Standardization method. The reconstruction explains 44.7% of the variance in the instrumental temperature records during the calibration period (1962–2002), and captures temperature variability over a broad region of the TP. Warmer than average Augusts were found during the periods 1446–1494, 1509–1522, 1553–1567, 1797–1812, 1845–1905 and 1918–2002. Cooler than average Augusts occurred from 1385–1416, 1426–1445, 1495–1508, 1523–1552, 1568–1686, 1695–1718, 1725–1796, 1813–1844 and 1906–1917. A warming trend in the 20th century was unprecedented during the past six centuries. The reconstruction closely matched other tree-ring summer temperature reconstructions from neighboring regions, as well as patterns from ice-core δ18O data, and fluctuated in synchrony with Northern Hemisphere temperature reconstructions. [Copyright &y& Elsevier]

Abstract: The provenance of upper Cretaceous strata in the Tethys Himalaya provides critical constraints on the closure time of the Neo-Tethys Ocean and the initial India–Asia collision. This paper reports detailed petrographic studies, in-situ detrital zircon U–Pb ages and Lu–Hf isotopic analyses, whole rock Nd-isotopes, and Cr–spinel electronic microprobe data from upper Cretaceous clastic sedimentary rocks of the Tethys Himalaya near Gyangze, southern Tibet. The Berriasian–Coniacian Jiabula Formation consists of black mudstone, chert and minor quartz arenite, and is dominated by detrital zircons with Archean–Cambrian U–Pb ages which were most likely derived from the Indian continent. Overlying conformably is the Santonian–Maastrichtian Chuangde Formation, which consists of red shale, limestone and chert. The Chuangde Formation is in turn overlain by the late Maastrichtian–late Paleocene Zongzhuo Formation, which is composed of black mudstone and lithic sandstone enclosing various olistoliths of sandstone, limestone and chert. The Rilang conglomerate is a lens which is located within the upper part of the Zongzhuo Formation and consists of an upward-thinning and fining succession of volcanic conglomerate, sandstone and black mudstone. The Zongzhuo Formation and the Rilang conglomerate record an abrupt influx of Cretaceous zircon grains with juvenile Hf isotopic compositions, arc-related Cr–spinels and positive εNd(0) sediments, suggesting an arc and suture-zone provenance. The change in provenance of upper Cretaceous strata from the southern Indian continent to a northern arc and suture zone is attributed to either (1) initial collision between the Indian plate and Lhasa terrane, or (2) initial collision between the Indian plate and an intra-oceanic arc. We prefer option (1) that the initiation of India–Asia collision occurred during Maastrichtian (~70–65Ma). [Copyright &y& Elsevier]

Abstract: A new muon–neutron telescope has been constructed at Yangbajing, Tibet, China. It has been successfully operating for 2 years. At the same location in Yangbajing, cosmic rays are simultaneously monitored by a neutron monitor, a neutron telescope and a muon telescope. It is expected that these instruments will obtain sufficient information regarding energetic solar cosmic rays to greatly benefit research and understanding of the space environment of the Earth. This paper describes the newly built muon–neutron telescope. [ABSTRACT FROM AUTHOR]

Aim of the study: Based on the authors’ collection of specimens used as Jie-Ji in local Tibetan areas, China, and taxonomic determination, this paper aims to give a list of medicinal plants as Jie-Ji, formally identify the ones recognized as Jie-Ji Ga-Bao or Jie-Ji Na-Bao and to offer basic data for further studies on these Tibetan herbs. Materials and methods: Local herbalists were visited in Tibetan areas, China to observe which plants were being used as Jie-Ji. Samples of the indigenous plants were collected at the same time. Also, the medicinal plants as Jie-Ji were taxonomically identified. Results: A list of medicinal plants including 10 species of Jie-Ji in local Tibetan areas is given, including their morphological pictures used for identification. Conclusions: The origin of Jie-Ji is from 10 species of the Section Cruciata, Genus Gentiana (Gentianaceae). five species with dark blue flowers are used as Jie-Ji Na-Bao, the other five with white flowers are used as Jie-Ji Ga-Bao. Also, Gentiana macrophylla Pall. with dark blue flowers in the Section Cruciata, Genus Gentiana is not the original plant of Jie-Ji Na-Bao. The species endemic to the province are used as the original plants of Jie-Ji only in local Tibetan area of the province. Finally, the drug use of Jie-Ji in Traditional Tibetan Medicine is reasonable and it is efficacious. [Copyright &y& Elsevier]

Abstract: This paper documents a new Permian–Triassic carbonate sequence which recorded the end-Permian mass extinction in the isolated oceanic setting of Neotethys in southwestern Tibet, China. The sequence is over 350m thick and consists of the Gyanyima and the Lower Lanchengquxia formations in ascending order. The Lopingian (Late Permian) Gyanyima Formation is composed of fossiliferous reddish carbonates dominated by Colaniella grainstone and reef facies including fenestrate/sponge/coral framestone and bafflestone. 156 species are recognized from the Lopingian Gyanyima Formation. Composite ranges of brachiopods, ostracods, rugose corals and foraminifers at the Gyanyima Section suggest that evolution and diversification of Permian marine organisms continued to the end-Permian preceding a major faunal extinction close to the Permian–Triassic boundary (PTB), coincident with a 2–3‰ negative shift of δ 13Ccarb. The timing and accelerating extinction pattern and the negative δ 13Ccarb excursion are largely comparable with those reported from many previously-documented sections on continental shelf environments. Based on a detailed lithofacies analysis, the latest Permian reefal facies is sharply replaced by ostracod/crinoid packstone/grainstone with abrupt abundant occurrences of Early Triassic conodonts at the Gyanyima Section. This is then followed by thrombolitic microbialite, stromatolite, packstone containing abundant spherical microbes, and bivalve/ammonoid packstone of tidal and intertidal facies. This distinct lithofacies and biofacies shift would, therefore, suggest a dramatic faunal community and environmental change across the PTB. Distinct palaeoclimate fluctuations through the P–T interval are also indicated by the alternation of warm- and cool-water faunas through the uppermost part of the succession. The lower part of the Gyanyima Formation is characterized by a warm condition as indicated by Cathaysian-dominated fossils. This was then followed by a mild cooling event as suggested by the occurrence of many distinct peri-Gondwanan elements and absence of compound corals. The latest Changhsingian is characterized exclusively by warm-water faunal elements of Cathaysian affinities, together with the negative shift of δ 13Ccarb, suggesting a rapid warming event at the very end of Permian in association with much more widespread volcanic activities than we thought before. [Copyright &y& Elsevier]

Abstract: The performance of a photovoltaic solar assisted heat pump (PV-SAHP) with variable-frequency compressor is reported in this paper. The system is a direct integration of photovoltaic/thermal solar collectors and heat pump. The solar collectors extract the required thermal energy from the heat pump and at the same time, the cooling effect of the refrigerant lowers the working temperature of the solar cells. So this combined system has a relatively high thermal performance with an improved photovoltaic efficiency. To adapt to the continuously changing solar radiation and ambient temperature conditions, the refrigerant mass flow rate should match the heat gain at the evaporator accordingly. A variable-frequency compressor and an electricity-operated expansion valve were used in the proposed system. Mathematical models were developed to evaluate the energy performance of the combined system based on the weather conditions of Tibet. The simulation results indicated that on a typical sunny winter day with light breeze, the average COP could reach 6.01, and the average electricity efficiency, thermal efficiency and overall efficiency were 0.135, 0.479 and 0.625 respectively. [Copyright &y& Elsevier]

Abstract: Rising as “the roof of the world” the Tibetan plateau is now underlain with the thickest continental crust on Earth. How and when was this crust formed, which would have exerted pivotal controls to the formation of the plateau, has long been an issue of hot debates. This paper reports zircon U–Pb ages and Hf isotope data for postcollisional (~30–9Ma) adakites in the southern Lhasa terrane, southern Tibet. A comparative analysis of whole-rock rare earth element geochemistry and zircon Hf isotopes between the adakites and associated Gangdese igneous rocks suggests that the Tibetan crust underwent a major phase of tectonic thickening between ca. 45 and 30Ma in the region. The lower part of the thickened crust consisted prevailingly of mafic lithologies, which we argue to have resulted from intense basaltic underplating and subsequent remelting that took place during the Late Cretaceous and Eocene time related to the Neotethyan subduction processes including breakoff of the subducted slab at ca. 50Ma in the early stage of the India–Asia collision. These processes were responsible for not only the juvenile crust formation but also for the creation of a thermally softened lithosphere in the southern Lhasa terrane. The indentation of India, consequently, caused distributed lithospheric thickening with formation of an orogenic root beneath southern Tibet. Root foundering during the Oligocene gave rise to the adakitic magmatism, regional topographic uplift, and onset of northward underthrusting of the Indian plate that has since played a key role in forming the entire Tibetan plateau. [Copyright &y& Elsevier]

Abstract: Mineral deposits associated with continental collision are abundant in many orogenic systems. However, the metallogenesis of collisional orogens is often poorly understood, due to the lack of systematic studies on the genetic links between collisional processes and ore formation in collisional orogenic belts. This paper reviews the key metallogenic settings and resultant collision-related ore deposits in the Tibetan Orogen, created by Indo-Asian collision starting in the early Cenozoic. The resulting synthesis leads us to propose a new conceptual framework for Tibetan metallogenic systems, which may aid in deciphering relationships among ore types in other comparable collisional belts. This framework includes three principal metallogenic epochs in the Tibetan orogen, and metallogenesis in: (1) a main-collisional convergent setting (∼65–41 Ma); (2) a late-collisional transform structural setting (∼40–26 Ma); and (3) a post-collisional crustal extension setting (∼25–0 Ma), each forming more than three distinct types of ore deposits in the Tibetan orogen. The main-collisional metaollognesis took place in a convergent setting, i.e., a collisional zone, characterized by collision-related crustal shortening and thickening, associated syn-peak metamorphism and two distinct magmatic series (Paleocene–Eocene crust-derived low-fO2 granitoids generated by crustal anatexis and Eocene high-fO2 granitoids formed by MASH processes at the base of the Tibetan crust). Metallogenesis during this period formed Sn–W–rare metal deposits related to the low-fO2 granitoids, skarn-hosted Cu–Au polymetallic deposits related to high-fO2 granitoids, and orogenic-type Au deposits formed by CO2-dominant metamorphic fluids. Late-collisional metallogenesis occurred mainly in a transform structural setting dominated by Cenozoic strike-slip faulting, shearing, thrust systems, and associated potassic magmatism in eastern Tibet, and formed the most economically-significant metallogenic province in the orogen. Four significant ore-forming systems are recognized in the transform zone: porphyry Cu–Mo–Au systems associated with potassic adakitic melts and controlled by Cenozoic strike-slip faults; orogenic-type Au systems related to large-scale left-slip ductile shearing; REE-bearing systems associated with lithospheric mantle-derived carbonatite–alkalic complexes; and Zn–Pb–Cu–Ag systems related to basinal brines and controlled by Cenozoic thrust structures and subsequent strike-slip faults developed in the Tertiary foreland basin. Post-collisional metallogenesis occurred in a crustal extension setting, characterized by lithospheric mantle thinning or delamination at depth, crustal shortening at a lower structural level and synchronal extension at shallower levels. The resulting ore-forming systems include: (1) porphyry Cu–Mo ore systems related to high-K adakitic stocks derived from the newly-formed thickened mafic lower-crust; (2) vein-type Sb–Au ore systems controlled by the south Tibetan detachment system (STDs) and the metamorphic core complex or thermal dome intruded by lecuogranite intrusions; (3) hydrothermal Pb–Zn–Ag ore systems controlled by the intersections of N–S-striking normal faults with E–W-trending thrust faults; and (4) spring-type Cs–Au ore systems related to geothermal activity driven by partial melting of the upper crust. Associated ore deposits lie mostly within the mid-Miocene Gangdese tectono-magmatic belt, in which the scavenging role of fluids derived from evolved magma systems or dewatering of rift basins, and finally discharging at intersections of the orogen-transverse and -parallel faults are extremely important for formation of the low-temperature hydrothermal deposits. Based on the synthesis of deposits in the Tibetan orogen and comparison with the metallogenesis of other orogenic systems, a more complete classification for these collision-related deposits can be proposed. [Copyright &y& Elsevier]

Abstract: Bioenergy is the major domestic energy for rural households in developing countries due to its cheap or easy-getting characteristics. Productive use of bioenergy is an important strategy for rural households to improve not only their income, but also their health, living environment and so on. In Tibet of China, which is rich in cattle dung and firewood as the major energy sources for rural households, the efficiency of energy utilization is just about 10%. In order to improve energy utilization efficiency and the living conditions for rural residents, the Tibet Autonomous Region government introduced residential biogas model (RBM) to local households, which was a comprehensive utilization system of energy integrated with residential biogas digester, vegetable greenhouse and livestock shed. This paper aims to show the productive use of the bioenergy by the RBM, which could be depicted as the feasibility and the benefits on economic, eco-environmental and social aspects of biogas utilization, based on household questionnaires in Panam County. In RBM, biogas digester works as the biomass material supplement loop to transform originally biomass flow from single-direction to recycling-direction. The results indicate that the output of unit biogas digester could replace 1.44t of firewood, 1.65t of agricultural residues and 1.75t of cattle dung, respectively. The net incremental benefit of RBM could reach 5550.72 Yuan in 15 years. The reduced amount of CO2 emission when substituted by biogas in other agricultural areas and the areas of semi-agricultural and semi-husbandry in Tibet could be (76.66–79.89)×104 t/year and the capability for nitrogen storage could achieve (0.39–0.99)×104 t/year. The amount of cattle dung replaced by biogas could reach 78.29×104 t/year; this means that the saved cattle dung, 3.51t/hm2, could be reallocated back to cultivated land to improve the soil fertility and to keep the balance of nutrient elements in cultivated land. Biogas utilization reduces the labor opportunity costs of women compared to use of traditional bioenergy sources. It could be concluded that the productive use of bioenergy through RBM in this area has its capability to release the current pressures on biomass sources by adjusting patterns of rural energy consumption, and to improve the conditions of health, environment, economy and energy conservation. [Copyright &y& Elsevier]

Abstract: The Karakorum fault zone (KFZ), composed of strike-slip faults, has played an important role in intra-continental deformation during the Cenozoic convergence between the Indian and Eurasian plates. However, the spatial and temporal evolution of the KFZ remains under debate. This paper reports new zircon U–Pb Sensitive High Resolution Ion MicroProbe (SHRIMP) and biotite 40Ar/39Ar ages for samples from the fault zone to clarify the timing of events. The ages of Zircon U–Pb fall mainly around 47–50 Ma, which corresponds to a period of important magmatic activity of the Gangdese granitic belt (also known as the Trans-Himalayan magmatic belt). A metamorphic event followed in the period around 32 Ma, and that was then followed by a medium temperature cooling event between about 12 and 7.7 Ma. Biotite 40Ar/39Ar ages provide evidence that the 12–7.7 Ma cooling event coincides with the initiation of the KFZ cutting through the Ayilari granite. The Ayilari granite pluton does not seem to have experienced the separate 25–23 Ma cooling event, as shown in previous studies 60–80 km west of the current study area [Lacassin, R., Valli, F., Arnaud, N., Leloup, P.H., Paquette, J.L., Li, H., Tapponnier, P., Chevalier, M.L., Guillot, S., Maheo, G., Xu, Z., 2004. Large-scale geometry, offset and kinematic evolution of the Karakorum fault, Tibet. Earth and Planetary Science Letters 219 (3–4), 255–269.; Valli, F., Arnaud, N., Leloup, H.P., Sobel, E.R., Maheo, G., Lacassin, R., Guillot, S., Li, H., Tapponnier, P., Xu, Z., 2007. Twenty million years of continuous deformation along the Karakorum fault, western Tibet: a thermochronological analysis. Tectonics 26, doi: 10.1029/2005TC001913.; Valli, F., Leloup, P., Paquette, J., Arnaud, N., Li, H., Tapponnier, P., Lacassin, R., Guillot, S., Liu, D., Deloule, E., Xu, Z., Mahe´o, G., 2008. New U–Th/Pb constraints on timing of shearing and long-term slip-rate on the Karakorum fault. Tectonics 27, doi:10.1029/2007TC002184.]. We conclude that the 25–23 Ma cooling event bears no relationship to the activity of the KFZ, but resulted from a local metamorphic event caused either by a regional tectonic event (such as activity of the south Kailas thrust fault) or by magmatism around Shiquanhe (also known as Gar). The study of the KFZ around Namru supports the opinion that the KFZ propagated along the fault strike to the Gar-Menshi area around 12 Ma. [Copyright &y& Elsevier]

Abstract: Strongly foliated amphibolite clasts are found embedded within the ophiolitic mélange underlying the Xigaze Ophiolite near Bainang and Angren, Yarlung Zangbo Suture Zone, Southern Tibet. These high-grade amphibolites are interpreted as remnants of a dismembered subophiolitic metamorphic sole that would have formed during the inception of a subduction. They include garnet-clinopyroxene amphibolites, clinopyroxene amphibolites and common amphibolites. Petrographic descriptions, mineral chemistry and thermobarometry of these rocks can be found in a companion paper [Guilmette, C., Hébert, R., Dupuis, C., Wang, C.S., Li, Z.J., 2008. Metamorphic history and geodynamic significance of high-grade metabasites from the ophiolitic mélange beneath the Yarlung Zangbo Ophiolites, Xigaze area, Tibet. Journal of Asian Earth Sciences, 32, 423–437.]. The geochemistry of the amphibolites confirms that their protoliths were igneous mafic rocks of basaltic to pyroxenitic composition that were likely part of an upper oceanic crust. Rare Earth Elements contents are suggestive of an N-MORB origin. However, enriched LILEs and depleted Nb–Ta–Ti when compared to N-MORBs rather suggest a suprasubduction zone influence. A large proportion of the overlying ophiolitic mafic rocks share the same geochemical characteristics, suggesting the protoliths of the amphibolites might have crystallized in the same environment as the Xigaze ophiolitic crust, likely in a back-arc basin. 40Ar/39Ar step-heating dating of hornblende concentrates from three samples yielded ages of 123.6±2.9 Ma, 127.7±2.2 Ma and 127.4±2.3 Ma. These cooling ages are slightly younger or overlapping magmatic and sedimentary ages obtained from the overlying ophiolite. All these new data support a model in which the ophiolitic crust and the protolith of the amphibolites were formed along the same spreading center above a subduction zone. The demise of the early subduction circa 130 Ma forced the inception of a new subduction zone at the SSZ spreading axis, burying SSZ mafic rocks underneath a SSZ ophiolitic mantle. [Copyright &y& Elsevier]

Abstract: The Lhasa terrane has long been interpreted as a simple tectonic block rifted from Gondwana during the late Paleozoic and then drifted northward before finally amalgamating with the Qiangtang terrane during the Early Cretaceous. In this paper we document Permian peraluminous granites near Pikang in the southern margin of the central Lhasa terrane, close to the recently documented Songdo eclogite of Permian age. Zircon SHRIMP and LA-ICPMS U–Pb dating for a Pikang granite sample gives an identical crystallization age of about 263 Ma and a wide age range of inherited zircons (283–2141 Ma). In situ Hf isotopic analyses for 20 zircons of 263 Ma yielded ε Hf(t) values of −4.5 to +1.9. The Pikang granites have high A/CNK values (≥1.08) and high normative corundum (1.3–2.0%), indicative of peraluminous S-type granite. They are characterized by moderately negative Eu anomalies (Eu/Eu⁎=0.48–0.61), and strongly negative Ba, Nb, Sr, P and Ti anomalies. The granites have high ε Nd(t) values (−6.4 to −6.0) and low initial 87Sr/86Sr ratios (0.7082–0.7096) relative to melts derived from mature continental crust. These rocks are interpreted to have been generated by mixing between mantle melts and their induced melting of mature crustal materials. We interpret the Pikang peraluminous granite magmatism, the regional angular unconformity between the Middle and the Upper Permian and the eclogite of the same metamorphic age (∼262 Ma) from the same geotectonic location to represent different products of a common event in time and space. We tentatively term this common event as syncollisional orogeny, i.e., “the Permian Gangdese Orogeny”. We further hypothesize that the orogeny may be genetically associated with the collision between the Lhasa terrane and the northern margin of Australia, following the closure of the Paleo-Tethyan Ocean south of the Lhasa terrane. [Copyright &y& Elsevier]

• The induced factors of the Baige landslide are comprehensively investigated. • The Baige landslide is caused by deep-seated gravitational slope deformation. • River downcutting is a prerequisite for the evolution of the Baige landslide. • Earthquake contributes to accelerating the development of the Baige landslide. On October 11 and November 3, 2018, two successive landslides happened at the same location near Baige Village in Tibet of China and dammed the Jinsha River twice. The induced factors and formation mechanism of the Baige landslide are still being questioned. In this paper, high-resolution topographic data, multi-temporal remote sensing images (including the unmanned aerial vehicle (UAV) 3D image, remote sensing, and Geographical Information Systems (GIS) techniques), rainfall data, seismic records, comprehensive field investigations, and numerical simulations are used to identify the main characteristics, the induced factors, and the formation mechanism of the event. The results show that deep-seated gravitational slope deformations play an important role in the evolution process of the Baige landslide; river downcutting is a prerequisite for the progressive evolution of the gravitational slope deformation behavior of the Baige landslide, whereas earthquake plays a catalytic role in the development of the gravitational slope deformation of the Baige landslide. The Baige landslide would be a typical case study for understanding the formation mechanism of large-scale landslides along the Jinsha River. [ABSTRACT FROM AUTHOR]

• Sustainability index based on the RRV concept was adopted to evaluate drought. • CA-Markov was adopted to predict future drought. • The spatio-temporal variability and trends of drought in China was studied. Drought threatens both social and economic development, and it is necessary to develop a comprehensive drought index and a method of predicting future drought occurrence to enable effective associated management and warnings. However, barring a few, current drought indexes are not comprehensive; for example, they ignore the ability to recover from drought, and drought prediction does not consider spatial and temporal characteristics. In this study, the Sustainability Index (SI), which considers reliability, resilience, and vulnerability, was used to identify agricultural drought, and the Cellular Automata-Markov (CA-Markov) was used in drought prediction. In order to reflect the characteristics of crop water deficit in agricultural drought, this paper uses the Permanent Wilting Point (PWP) as the threshold; droughts are defined as soil moisture < PWP. The results of SI from 1951 to 2015 in China showed that the drought was most severe in the western Northwest (WNW) region; the drought was mild in the South (S), Southwest (SW), and Tibet regions; and the drought was relatively severe in the North (N), eastern Northwest (ENW), and Northeast (NE) regions. The Mann-Kendall test was used to characterize SI trends over the past 65 years. Drought in the northern WNW and Tibet regions significantly improved, whereas that in the southern SW, N, and eastern NE regions intensified. The prediction of drought occurrence for 2016–2020 and 2021–2025 using the CA-Markov showed that overall drought in China will be alleviated. The SI and CA-Markov adopted in this study could be used in the identification and prediction of agricultural drought or other drought categories, and could be used in local drought management. [ABSTRACT FROM AUTHOR]

Abstract: A new solar neutron telescope has been constructed at Yangbajing, Tibet (600g/cm2) and has been successfully operated for 8 years. During this time several interesting events were observed in coincidence with large solar flares. In this paper the authors discuss a directional count rate enhancement 1998 November 28 as to whether it is related to solar phenomena or not. We use this event to evaluate the sensitivity of the solar neutron telescope and discuss the detection limit for solar neutrons and high energy solar protons of this detector. [Copyright &y& Elsevier]

Abstract: An in situ testing of a selected railway embankment in Qingshuihe region, Tibet Plateau, is described where no artificial protection measure was employed. Based on the results obtained, characteristics of the distribution of geotemperature and settlement of the embankment are examined. An assessment of long-term stability of the embankment is made, and a kind of efficient engineering treatment is recommended in this paper. The study reveals: a) although the permafrost table did not move after embankment construction, the layer between ground surface and the permafrost table approached the phase-transition critical state, i.e. 0.0 °C. This layer is about 3.0 m thick, and is the major source of embankment settlement; b) the varying heat-absorption at different locations along the cross-section of the embankment leads to a differential settlement, and results in the longitudinal cracking; c) the settlement developed at a constant rate (about 0.06 m/year in the middle of the embankment) during the complete test period; d) the optimal railway embankment height differs from that for highways, and should be less. Further study of the optimal height should be carried out comprehensively and the results applied to engineering practice immediately, since this could not only keep the permafrost table stable but also limit the differential settlement to an acceptable level; e) asymmetrical protection measures should be employed to reduce the differential settlement and longitudinal cracking; f) it is most important that embankment construction in permafrost area be carried out during the cold season. [Copyright &y& Elsevier]