Origin of the Yueguang gold deposit in Xinhua, Hunan Province, South China: insights from fl uid inclusion and hydrogen–oxygen stable isotope analysis

The Yueguang gold deposit is located in Fengjia,Xinhua County,Hunan Province,South China.It represents a recently discovered small-scale gold deposit situated in the southwestern region of the Jiangnan Orogenic Belt,west of the Baimashan granitic batholith.In order to discern the characteristics of the ore-formingfluids,the underlying mineralization processes,and establish a foundation for the origin of the Yueguang gold depositfluid inclusion micro-thermometry,as well as quartz hydrogen and oxygen isotope analysis,have been carried out on samples obtained from various stages of mineralization.The hydrothermal miner-alization stages within the Yueguang gold deposit can be categorized into three stages:(i)the barren,pre-ore quartz-pyrite stage(Stage Ⅰ),the quartz-pyrite-gold stage(Stage Ⅱ),and the post-ore quartz-carbonate stage(Stage Ⅲ),with the second stage being the main mineralization stage.Thefluid inclusions identified in samples from the main min-eralization stage can predominantly be described with the NaCl–H_(2)O and CO_(2)–NaCl–H_(2)O systems.These inclusions display homogenization temperatures ranging from 158.8 to 334.9℃,and thefluid salinity ranges from 0.3%to 4.0%(wt.%NaCl equiv.).Laser Raman spectroscopy analysis of individual inclusions further reveals the presence of gas-phases such as CO_(2),CH_(4),and N_(2).Isotopic analysis indicatesδ^(18)Ofluid values ranging from 3.95 to 6.7‰ and δDH_(2)O values ranging from-71.9 to-55.7‰.These results indi-cate that the ore-formingfluid of the Yueguang gold deposit belongs to metamorphic hydrothermalfluids of middle-low temperature and low salinity.In the process of ore formation,gold is transported in the form of Au(HS)2-complexes,with gold deposition being driven byfluid immiscibility.Therefore,the Yueguang gold deposit is categorized as an orogenic gold deposit dominated by metamorphic hydrother-malfluid.It may become a new target for gold exploration in the Baimashan region,central Hunan Province.

Forest height mapping using inventory and multi-source satellite data over Hunan Province in southern China

Background:Accurate mapping of forest canopy heights at a fine spatial resolution over large geographical areas is challenging.It is essential for the estimation of forest aboveground biomass and the evaluation of forest ecosystems.Yet current regional to national scale forest height maps were mainly produced at coarse-scale.Such maps lack spatial details for decision-making at local scales.Recent advances in remote sensing provide great opportunities to fill this gap.Method:In this study,we evaluated the utility of multi-source satellite data for mapping forest heights over Hunan Province in China.A total of 523 plot data collected from 2017 to 2018 were utilized for calibration and validation of forest height models.Specifically,the relationships between three types of in-situ measured tree heights(maximum-,averaged-,and basal area-weighted-tree heights)and plot-level remote sensing metrics(multispectral,radar,and topo variables from Landsat,Sentinel-1/PALSAR-2,and SRTM)were analyzed.Three types of models(multilinear regression,random forest,and support vector regression)were evaluated.Feature variables were selected by two types of variable selection approaches(stepwise regression and random forest).Model parameters and model performances for different models were tuned and evaluated via a 10-fold cross-validation approach.Then,tuned models were applied to generate wall-to-wall forest height maps for Hunan Province.Results:The best estimation of plot-level tree heights(R2 ranged from 0.47 to 0.52,RMSE ranged from 3.8 to 5.3 m,and rRMSE ranged from 28%to 31%)was achieved using the random forest model.A comparison with existing forest height maps showed similar estimates of mean height,however,the ranges varied under different definitions of forest and types of tree height.Conclusions:Primary results indicate that there are small biases in estimated heights at the province scale.This study provides a framework toward establishing regional to national scale maps of vertical forest structure.

Fixed Ammonium Content and Maximum Capacity of Ammonium Fixation in Major Types of Tillage Soils in Hunan Province,China

In order to understand the status of fixed ammonium, fixed ammonium content, maximum capacity of ammonium fixation, and their influencing factors in major types of tillage soils of Hunan Province, China, were studied with sampling on fields, and laboratory incubation and determination. The main results are summarized as follows： （1） Content of fixed ammonium in the tested soils varies greatly with soil use pattern and the nature of parent material. For the paddy soils, it ranges from 135.4 ± 57.4 to 412.8±32,4 mg kg^-1, with 304.7±96.7 mg kg^-1 in average; while it ranges from 59.4 to 435.7 mg kg^-1, with 230.1 ± 89.2 mg kg^-1 in average for the upland soils. The soils developed from limnic material and slate had higher fixed ammonium content than the soils developed from granite. The percentage of fixed ammonium to total N in the upland soils is always higher than that in the paddy soils. It ranges from 6.1 ±3.6% to 16.6±4.6%, with 14.0% ±5.1% in average for the paddy soils and it amounted to 5.8±2.0% to 40.1 ± 17.8%, with 23.5 ± 14.2% in average for upland soils. （2） The maximum capacity of ammonium fixation has the same trend with the fixed ammonium content in the tested soils. For all the tested soils, the percentage of recently fixed ammonium to maximum capacity of ammonium fixation is always bellow 20% and it may be due to the fact that the soils have high fertility and high saturation of ammonium-fixing site. （3） The clay content and clay composition in the tested soils are the two important factors influencing their fixed ammonium content and maximum capacity of ammonium fixation. The results showed that hydrous mica is the main 2：1 type clay mineral in 〈 0.02 mm clay of the paddy soils, and its content in 0.02-0.002 mm clay is much higher than that in 〈 0.002 mm clay of the soils. The statistical analysis showed that both the fixed ammonium content and the maximum capacity of ammonium fixation of the paddy soils were positively correlated with the total 2：1 type clay mineral content and hydrous mica content in 〈 0.02 mm clay and 0,02-0.002 mm clay at the significant level of P0.01 or P0.05, respectively, but not correlated with the total 2：1 type clay mineral content and hydrous mica content in 〈0.002 mm clay significantly, It demonstrated that the ammonium-fixing matrix of the tested soils mainly exists in the 0.02-0.002 mm clay. The above-mentioned results showed that fixed ammonium is a major form of N in the tillage soils in Hunan Province, China. It would play an important role in N nutrition of crops, especially for upland crops, and deserve to be further researched.

Estimating health damage cost from secondary sulfate particles—a case study of Hunan Province,China

China's coal dominated energy pattern has resulted in large amount of SO 2 emissions. Estimate of the sulfur related health damage cost is necessary to help perform systematic cost benefit analysis and set national energy and emissions control priorities. Current researches were confined to gaseous SO 2 in urban areas; however, secondary sulfate (SO 2- 4) particles can exert serious impact in a wider region. Based on the concept of “intake fraction', CALPUFF long range dispersion model and 180 sample emission sources, multiple regression equation was obtained with good correlation( r =0 85), which illustrates that populations were key parameters to determine intake fraction but source characteristics were insignificant. Based on the formula and the population distribution data, county level intake fractions were mapped for Hunan Province(range: 1 1×10 -6 -3 2×10 -6 ) of China. A combination of county level SO 2 emissions with the intake fractions yields a total 1 98 tons of sulfate(SO 2- 4) inhalation, and resulting total health damage cost to be 0 76(willingness to pay approach, WTP) or 0 16(human capital approach, HC) billion USD in 1997, about 2.1% or 0 45% of GDP in Hunan in 1997. Average health damage cost per ton of SO 2 emission is 930(WTP) or 200 USD(HC). The results demonstrated that more stringent regulation should be forced.

Types of uranium deposits in central Zhuguang Mountains in Hunan Province,South China and their metallogenic regularity and prospecting directions

The central Zhuguang Mountains in Hunan Province is located at the junction of the three provinces,namely Hunan,Jiangxi,and Guangdong,where the famous Lujing uranium ore field lies.The uranium deposits occurring in this area are all granite-related and they can be divided into three types,namely endogranitic ones,perigranitic ones,and contact zone types.The endogranitic uranium deposits are mainly controlled by the structural alteration zones developing within granites,with fragmentation,hematitization,and alkali metasomatism as their main mineralization characteristics.The perigranitic uranium deposits are mainly produced in the carbonaceous,siliceous,and argillaceous composite layers of epimetamorphic rocks and are controlled by fractured zones formed due to interlayer compression.The contact zone type uranium deposits mainly occur in the contact parts between the granites and favorable horizons.They have developed in favorable sections where multiple sets of structures are combined and intersected.The main metallogenic regularities of uranium in the central Zhuguang Mountains are as follows.The basic conditions for the uranium mineralization in this area include the framework consisting of regional deep large faults and their associated multi-set multi-direction favorable metallogenic structures,multi-cycle and multi-stage uranium-rich rock masses,and uranium-rich folded basement.Meanwhile,the uranium deposits in this area are closely related to granites in terms of genesis and space and they are formed in different structural parts subject to the same metallization.Furthermore,based on the summary of the characteristics and regularities of uranium mineralization in this area,the controlling factors of different types of uranium deposits in the area were explored and six metallogenic target areas were predicted.All these will provide references for the exploration of uranium deposits in this area.

Spatial Distribution of Traditional Villages and Influence Factors in Hunan Province

To develop and protect traditional villages reasonably, this paper applied Arc GIS Spatial Analyst Tools to analyze spatial distribution and infl uence factors of 101 traditional villages in Hunan Province. The research showed the agglomerate distribution of traditional villages in Hunan; from the city scale, distribution of traditional villages was concentrated mainly in West Hunan Tujia Nationality Autonomous Prefecture, Chenzhou, Yongzhou, Huaihua and Shaoyang; concentrated distribution of traditional villages in the fi ve major geographic regions showed poor equilibrium, West Hunan had the most concentrated traditional villages, and South Hunan has the second most; relatively closed regional environment, perilous hills, inconvenient transportation, and underdeveloped social economy contributed to the protection of traditional villages, and they were all signifi cant infl uence factors for the distribution of traditional villages in Hunan.

Emergy analysis of paddy farming in Hunan Province, China： A new perspective on sustainable development of agriculture

The multi-functionality of paddy farming has become a hot issue recently. Paddy farming provides numerous ecosystem services that are crucial to human well-being. However, evaluation of the contribution of paddy farming to human well-being usually focus on its economic value, while its non-market services are usually ignored. Only evaluating the market profits or market relative benefits cannot reflect comprehensively the contribution of paddy farming to people＇s well-being. This will affect people＇s choices for or against paddy farming activities and people＇s opt for invest or not invest in it. A comprehensive evaluation of paddy farming can provide an important reference for the government and society to conserve the multi-functionality of paddy farming and achieve sustainable development. To this end, this paper reports a case evaluation of paddy farming in Hunan, the largest rice producing as well as rice yield province in China, and uses emergy theory to make a comprehensive evaluation for paddy farming. The emergy evaluation results of the paddy ecosystem in Hunan are as follows： in 2010, the input emergy of the paddy ecosystem in Hunan is 2.51E＋22 sej and the output emergy is 6.31E＋22sej. For the input emergy, the part from natural resources is 1.96E＋21 sej and the part from human society is 2.32E＋22sej; for the output emergy, the part from products is 2.22E＋22 sej, the part from impositive externality is 4.16E＋22 sej and the part from negative externality is –7.41E＋20 sej. Taking the non-market outputs into consideration, the gains from the human economic society＇s 1 $ input in paddy farming, emergy sustainability index（ESI） and emergy profit rate are respectively 2.73 $, 3.53 and 151.31%. If the evaluation leave out the non-market output, the three indexes are only 0.96 $,1.24 and 30.67%. The research results show that non-market services of paddy farming contribute significantly to human well-being. Therefore, in order to protect the multi-functionality of paddy farming and achieve the sustainable management,the government should take reasonable measures and make incentive plans.

A New Species of the Genus Tylototriton (Urodela: Salamandridae) from Northeastern Hunan Province, China

We describe a new species from the family Salamandridae from northeastern Hunan Province of China based on morphological and molecular genetic evidences.The new species,Tylototriton liuyangensis,is a member of the T.asperrimus group,and shares a number of similarities with T.wenxianensis and T.broadoridgus.The dorsal surface of the new Tylototriton species is completely black,with nodule-like warts distributed evenly along the lateral margin of dorsal body,and there is no transverse striae between the warts.There are several diagnostic characters of the new species that differ from those of T.wenxianensis and T.broadoridgus as follows：（1）the interorbital space（IOS）is comparatively wide;（2）there is a bony ridge present on the dorsal head surface,running along the upper eyelids;（3）the space between axilla and groin（AGS）is comparatively large,with the mean male AGS approximately equal to 50%of the snout-vent length（SVL）and the mean female AGS being 53%of SVL;and（4）there is a small genital armature on the anterior angle of labial folds present inside the anal fissure of adult males during the breeding season.The result from the molecular phylogenetic analysis of the genus Tylototriton（including the type specimen of the new species）based on the complete DNA sequence of the mitochondrial ND2 gene（1035 bp）indicated that the new species was similar to T.wenxianensis,T.dabienicus,and T.broadoridgus,but formed an independent clade.This result was consistent with the morphological analysis above,supporting that the Liuyang Population represented a distinct species.

Tectonic Characteristics and Emplacement Mechanism of Dayishan Granite in Hunan Province, China

Dayishan granite, a significant metallogenic-rock body located in Shaoyang-Chenxian tectonomagmatic belt of Hunan Province, was controlled by 'Dayishan-type' fault pattern. Based on the study of tectonic setting and geological features of the grantie, it is concluded that the tectonic system controlling magmatic emplacement is a shear folded-fauted zone which resulted from NW-trending convergent strike-slip faulting. The close relationship between the temporal-spatial distribution, emplacement mechanism of Dayishan granite and the strike-slip faulting is detailed.

Analysis of an Abrupt Rainstorm Process in Central Hunan Province

[Objective] The aim is to expound the abrupt rainstorm in the central Hunan Province on May 6 in 2010.[Method] By dint of NCEP 1°×1° reanalysis data,routine observation data,auto-station precipitation and FY-2C satellite data,the large-scale circulation background and physical condition during the large rainstorm period from the night on May 5 to 6 in 2010 were analyzed.The large scale environment,meso-scale characteristics and potential causes for the formation of large precipitation were revealed.By dint of FY-2D satellite and water-vapor cloud image,infrared cloud image,4 black light temperature,the variation characteristics of heavy rainstorm convection system were analyzed.[Result] Under the favorable environment background,the rainstorm was induced by the meso-scale convection system,and it had close relation with the upper-air trough,shear line in the middle and low layer,ground weak and cold air and the torrent in the upper and low latitude.The result of all kinds of physical quantities suggested that the meso-scale rainstorm above the air had distinct characteristics and the heavy precipitation was in the middle Hunan Province.It was caused by meso-system.The dynamic dry belt above the satellite,TBB=-60℃ center and the large value area of the gradient could provide references for the forecast and pre-warning of large rainstorm.[Conclusion] The study accumulated experiences for the forecast and report of rainstorm in Hunan Province.

Characteristics of the ore-forming fluid in the Huayuan Pb-Zn ore filed, Northwest of Hunan Province, China

1 Geological Setting The Huayuan Pb-Zn ore field in Xiangxi is located in the southeastern margin of the Yangtze block and the mid-segment of the West Hunan-West Hubei metallogenic belt.The exposed stratum are the lower

Assessment on the component pattern of mountain vacation potential suitability in Hunan Province, China

In China,mountain destinations offer more opportunities for vacation than beaches and springs,with a larger national coverage,richer landscapes and various diverse folk cultures.Hunan Province,for example,serves as a typical mountain tourism destination.Our research aims to assess the potential suitability and component pattern of holidaymaking in Hunan Province to support for scientific endeavors and sustainable use of mountain resources in Hunan.An approach for mapping potential suitability was constructed based on Weighted Linear Combination(WLC)of six primary factors including terrain,climate suitability period,biology and environment,human activity culture,hydrological landscape,and road infrastructure,which is calculated on the base of eleven secondary factors used as suitability criteria.Analytic hierarchy process(AHP)and geographic information system(GIS)were also integrated into the evaluation models to prepare six single and complex factor suitability maps for mountain vacation.Multivariate clustering was used to clarify the component pattern of single factor combinations in each mountain vacation suitability index(MVSI)class.The results have shown that:1)Regions with high suitability are distributed with characteristics of significant dispersion and limited aggregation;2)15.89%of the sample mountains are highly suitable,30.78%are moderately suitable,42.61%are marginally suitable and 10.72%are poorly suitable;3)The complexity of index combination corresponding to each level is different;4)Different combinations emphasize different destination needs.The study reveals the suitability class,characteristics,and limiting factors of mountain vacation in different geographical locations on the provincial scale.These elements play an instructive role in scientific decision-making and orderly exploitation of resources among Hunan’s Mountain destinations.Furthermore,the study can also be used as a basis for the suitability evaluation of mountain vacation in other areas.

Spatial Differentiation and Influencing Factors of Poverty Alleviation Performance Under the Background of Sustainable Development:A Case Study of Contiguous Destitute Areas in Hunan Province,China

Poverty eradication is a realistic requirement for the addressing of the urban-rural development imbalance.It consolidates the achievements of the poverty alleviation,and accelerates the realization of the United Nations Sustainable Development Goals.In research that deals with poverty,qualitative analysis is often used to study the connection between a single influencing factor and poverty reduction,and to solve regional poverty through government measures.However,these studies usually ignore the multidimensional nature of poverty,and the fact that poverty alleviation also needs to be approached from multiple perspectives.By constructing a theoretical framework of poverty alleviation performance from the perspective of sustainable development,this study selects contiguous poverty-stricken areas in the Hunan Province,China as the empirical study area,constructs an evaluation index system from the three dimensions of economic development,infrastructure and people’s livelihood security,and selects influencing factors from three aspects of‘population’,‘land’and‘industry’.The spatial differentiation characteristics and influencing factors of poverty alleviation performance in poverty-stricken areas were studied by using the methods of entropy weight method and geodetector.The results show:firstly,in the concentrated and contiguous poverty-stricken areas of the Hunan Province,the performance of poverty alleviation in the economic development makes little difference,showing a‘high-medium-low’cross-distribution pattern.The poverty alleviation performance of the infrastructure presents a distribution pattern of‘low in the middle and high on both sides.The poverty alleviation performance of people’s livelihood security has significant spatial differentiation characteristics,which all present a reunion distribution.The overall poverty alleviation performance varies greatly,showing a funnel-shaped distribution in space.Secondly,the spatial differentiation of poverty alleviation performance in the concentrated and contiguous poverty-stricken areas of the Hunan Province is the result of the combined effects of multiple factors.‘Population’is the dominant factor affecting the performance of poverty alleviation,‘land’is the basic factor that causes the spatial differentiation of poverty alleviation performance,and‘industry’is the key factor for the improvement of the poverty alleviation ability.

Trace Element Geochemistry of Devonian Strata in the Shizhuyuan Ore District, Hunan Province

1 Introduction Both the Qiziqiao Formation and Shetianqiao Formation,which controls the occurrence and distribution of a great deal of metal mineral resources,are extensively developed in southern Hunan province(Liu et al.,1998),showing quite important indicative significance to deep concealed metal mineral resources(Yu et al.,2003).The geochemistry characteristics of Devonian strata could not affect the spatial occurrence shape of orebody

Super-Large Pb-Zn Deposits Discovered in Danaopo,Huayuan County,Hunan Province

Geological Brigade 405 of Hunan Provincial Geology and Mineral Exploration and Development Bureau discovered the Danaopo and Yangjiazhai super-large Pb- Zn deposits through 5 years （2009-2014） of exploration in Huayuan County, Hunan Province. These deposits contain 208.4942 million tons of （332＋333） class Pb＋Zn ores and 4.8746 million tons of metal amounts, of which metal amounts of 333 class zinc are 4.1198 million tons and metal amounts of lead are 0.7548 million tons, associated with useful components of Cd, Ag and Se. In addition, the Limei, Qingshuitang and Yutang Pb-Zn deposits were proven betbre and this region has thus been ranked as a Pb-Zn ore resource base with a hundred-ton scale （Fig. 1）.

Ore-Forming Material Sources of the Shizishan Pb-Zn Deposit in Western Hunan Province,China

Objective The Shizishan Pb-Zn deposit is located in the southeastern margin of the Yangtze Block,and its Pb-Zn orebodies are mainly hosted in the Lower Cambrian Qingxudong Formation limestone.Previous researches have investigated the geological characteristics,geochemistry and fluid inclusions of this deposit.

The Meso-Scale Analysis of “6.18” Severe Rainfall Event in Hunan Province

[Objective]The aim was to analyze the mesoscale and small scale system that influenced the strong rainfall in Hunan from June 18 to 20 in 2010. [Method] By dint of regular observation material and rainfall in regional automatic station, TBB of FY-2C geostationary meteorological satellite, characteristics and causes of one heavy rainfall event in Hunan Province on 18-20 June 2010 were studied. [Result] The rainstorm happened under the southwest warm and wet torrent at the edge of subtropical high when the ground cold air intruded, which triggered the release of unstable energy. The water vapor from Bay of Bengal and South China Sea sent abundant water vapor to south China. The water vapor strengthened, which synchronized with the rainstorm. The ground mesoscale convergence line and the mesoscale low pressure intensified the rainstorm. Changes of pressure field reflected the changes of rainfall and indicated the location and movement of heavy rainfall. [Conclusion] The study provided theoretical basis to understand the rainstorm formation mechanism and improve disaster prevention capacity.

Non-ferrous Metal Industry in Hunan Province

In the last ten years (1982～1991) 2.26 Mt of 10 kinds of nonferrous metals had been pro-duced in Hunan Province. Up to date the mining capacity achieves 6.52 Mt, ore-dressing capacity--7.25 Mt, smelt capacity--334 kt and the processing capacity--113 kt. In 1991 the output of10 kinds of nonferrous metals amounted to 292.8 kt. At present Hunan Province produces alloys,oxides and other compounds for copper, aluminium, lead, zinc, antimony and mercury. Species ofrare-earth metals and its alloys produced in Hunan Province amount to 160 and more. In this

Interpretation of diagnosis and treatment scheme of COVID-19 in Hunan province (the third trial version) based on three factors and measures

The similarities and differences between"Novel Coronavirus Infected pneumonia in Hunan province(trial second edition)"and"Novel Coronavirus Infected pneumonia(Trial seventh edition)"released by the National Health Commission and their ideas were interpreted based on"suiting measures to three factors".①In Hunan program,the third version of the trial adjustment more suitable for local characteristics of the disease;②The prevention program population classification is clear,support,eliminate pathogenic factors of the primary and secondary distinct;③The cause of disease is prominent,damp and toxin are mixed with dryness,and the treatment is mainly to moisten the lung and clear away heat,and the prescription is mostly Xinliang light agent.

Research on the Consumption Function of Rural Residents in Hunan Province

Based on literature review,according to relevant consumption data in Hunan Statistical Yearbook and China Statistical Yearbook during1978-2009,the thesis selects three indexes involving the average income per rural resident,per capita living expenses of rural residents and percapita savings to conduct the unit root and co-integration test on the consumption and net income per rural residents in Hunan Province by adoptingthe generalized difference method and EVIEWS6.0,then according to the Modigliani Hypothesis of Consumption,Duesenberry Hypothesis of Con-sumption and Keynes Absolute Income Hypothesis,the thesis makes a fitting of Hunan consumption function model,aiming to find out the consump-tion function model suitable to Hunan Province.The results show that,Keynesian consumption function based on Absolute Income Hypothesis pas-ses the statistical test and econometric test,while the consumption function model based on Relative Income Hypothesis and that based on Life Cy-cle Hypothesis do not,which proves that the consumption function model based on Absolute Income Hypothesis is better suited for describing the re-lations between rural consumption and income in Hunan Province.Taking into account the low marginal propensity of consumption of the rural resi-dents in Hunan Province,the thesis proposes to expand consumption demand of rural residents:firstly,developing characteristic economy and im-proving the income level of rural residents;secondly,perfecting the social security system in rural areas and maintaining the consumption confi-dence of rural residents;thirdly,ameliorating the circulation system.