Geochemical and Petrological Studies on the Early Carboniferous Sidingheishan Mafic-Ultramafic Iintrusion in the Southern Margin of the Central Asian Orogenic Belt,NW China

The Sidingheishan mafic-ultramafic intrusion is located in the eastern part of the Northern Tianshan Mountain, along the southern margin of the Central Asian Orogenic Belt in northern Xinjiang autonomous region of China. The Sidingheishan intrusion is mainly composed of wehrlite, olivine websterite, olivine gabbro, gabbro and hornblende gabbro. At least two pulses of magma were involved in the formation of the intrusion. The first pulse of magma produced an olivine-free unit and the second pulse produced an olivine-bearing unit. The magmas intruded the Devonian granites and granodiorites.An age of 351.4±5.8 Ma(Early Carboniferous) for the Sidingheishan intrusion has been determined by U-Pb SHRIMP analysis of zircon grains separated from the olivine gabbro unit. A U-Pb age of 359.2±6.4 Ma from the gabbro unit has been obtained by LA-ICP-MS. Olivine of the Sidingheishan intrusion reaches 82.52 mole% Fo and 1414 ppm Ni. On the basis of olivine-liquid equilibria, it has been calculated that the MgO and FeO included in the parental magma of a wehrlite sample were approximately10.43 wt% and 13.14 wt%, respectively. The Sidingheishan intrusive rocks are characterized by moderate enrichments in Th and Sm, slight enrichments in light REE, and depletions in Nb, Ta, Zr and Hf. The εNd(t) values in the rock units vary from +6.70 to +9.64, and initial87Sr/86Sr ratios range between 0.7035 and0.7042. Initial206Pb/204Pb,207Pb/204Pb and208Pb/204Pb values fall in the ranges of 17.23-17.91,15.45-15.54 and 37.54-38.09 respectively. These characteristics are collectively similar to the Heishan intrusion and the Early Carboniferous subduction related volcanic rocks in the Santanghu Basin, North Tianshan and Beishan area. The low(La/Gd)PMvalues between 0.26 and 1.77 indicate that the magma of the Sidingheishan intrusion was most likely derived from a depleted spinel-peridotite mantle.(Th/Nb)PMratios from 0.59 to 20.25 indicate contamination of the parental magma in the upper crust.Crystallization modeling methods suggest that the parental magma of the Sidingheishan intrusion was generated by flush melting of the asthenosphere and subsequently there was about 10 vol%contamination from a granitic melt. This was followed by about 5 vol% assimilation of upper crustal rocks. Thus, the high-Mg basaltic parental magma of Sidingheishan intrusion is interpreted to have formed from partial melting of the asthenosphere during the break-off of a subducted slab.

SHRIMP Zircon U-Pb Age of the Sidingheishan Mafic-Ultramafic Intrusion in the Southern Margin of the Central Asian Orogenic Belt,NW China and its Petrogenesis implication

Objective The Sidingheishan mafic-ultramafic intrusion is located in the eastern part of the North Tianshan Mountains. This work used zircon U-Pb age data, bulk rock major and trace elements, Sr-Nd-Pb isotope data to assess mantle source characteristics and crustal assimilation of the parental magma of the Sidingheishan intrusion. We have also discussed the tectonic evolution of the southern margin of the Central Asian Orogenic belt in the Late Paleozoic.

Change of Vegetation Cover and Its Relationships with Climatic Factors in Large-area Eucalyptus Introduced Region of Yunnan

Taking Lancang County as a study area with a large area of eucalyptus introduction in Yunnan, spatiotemporal change characteristics of vegetation cover, as well as the relationships between Enhanced Vegetation Index（EVl） and climatic factors （temperature and precipitation） were analyzed by using the data of MODIS-EVI from 2005 to 2010. The results indicated that： （1） The vegetation cover was overall good, and the annual average values of EVl were greater than 0.395 and showed a slow increasing trend from 2005 to 2010 in study area; the monthly average values of EVl ranged from 0.296 to 0.538, and seasonal variability was obvious. Monthly average values of EVl usually fell to the lowest level in February and March, and reached the peak in July and August. From the perspective of space, average EVl over the years significantly varied in different towns of Lancang County. During 2005 -2010, in 92.534% area of total, vegetation coverage change were not obvious; in 7.25% area of total, vegeta- tion becoming better; only in 0.02% area of total, vegetation cover were getting worse. （2） Monthly average values of EVl were significantly correlated with monthly average rainfall in Lancang County. The maxima of monthly average EVI and rainfall appeared in August on summer, while the minima of monthly average EVl and rainfall appeared in February and January on winter respectively. （3） Monthly average EVl was somewhat relative with monthly average temperature. The maxima of monthly average EVl and temperature appeared in June and August respectively, while the minima appeared in January and February respectively.

Geochronology, geochemistry and geological significance of Early Cretaceous volcanic rocks from Niangniangshan Formation,Ningwu Basin, middle and lower reaches of the Yangtze River

Ningwu Basin is one of the Mesozoic continental volcanic basins in the middle and lower reaches of the Yangtze River.The volcanic rocks of the Longwangshan,dawangshan,Gushan and Niangniangshan formations,as well as the homologous subvolcanic rocks or small intrusions,are developed from old to new in the Ningwu Basin.Zircon U-Pb dating results show the latialite phonolite of Niangniangshan Formation was erupted at 128±1 Ma(i.e.,Early Cretaceous).The latialite phonolite contains moderate SiO2 contents(57.28%-60.96%)with high Na 2O+K 2O contents,belonging to shoshonite series.The samples have high REE contents,and display right-inclined REE distribution pattern.They are characterized by enrichment in some large ion lithophile elements(e.g.,LILEs,Rb,K),and depletion in some high field strength elements(e.g.,HFSEs,Nb,Ta,Ti).All volcanic samples have relatively depleted Nd isotopic compositions(ISr=0.707197--0.707878;εNd(t)=-0.5--0.9),indicating no genetic relationship with the lower crust of Yangtze plate,but a drift trend towards the EMII.The geochemical data suggest that the Early Cretaceous latialite phonolite was derived from the partial melting of an enriched lithospheric mantle metasomatized by subduction-related fluids in an arc-related setting.Based on the temporal and spatial distribution and geochemical variation characteristics of the regional volcanic rocks,it is suggested that the tectonic system within the study area changed from a subduction-related compression to an extensional environment in the early Early Cretaceous,which was caused by the ridge subduction of the Paleo-Pacific Ocean.

The mixing of multi-source fluids in the Wusihe Zn–Pb ore deposit in Sichuan Province, Southwestern China

The Sichuan-Yunnan-Guizhou(SYG)metallogenic province of southwest China is one of the most important Zn-Pb ore zones in China,with^200 Mt ZnPb ores at mean grades of 10 wt.%Zn and 5 wt.%Pb.The source and mechanism of the regional Zn-Pb mineralization remain controversial despite many investigations that have been conducted.The Wusihe Zn-Pb deposit is a representative large-scale Zn-Pb deposit in the northern SYG,which mainly occurs in the Dengying Formation and yields Zn-Pb resources of^3.7 Mt.In this paper,Zn and S isotopes,and Fe and Cd contents of sphalerite from the Wusihe deposit were investigated in an attempt to constrain the controls on Zn and S isotopic variations,the potential sources of ore-forming components,and the possible mineralization mechanisms.Both theδ66Zn andδ34S values in sphalerite from the Wusihe deposit increase systematically from the bottom to the top of the strata-bound orebodies.Such spatial evolution inδ66Zn andδ34S values of sphalerite can be attributed to isotopic Rayleigh fractionation during sphalerite precipitation with temperature variations.The strong correlations between the Zn-S isotopic compositions and Fe-Cd concentrations in sphalerite suggest that their variations were dominated by a similar mechanism.However,the Rayleigh fractionation mechanism cannot explain the spatial variations of Fe and Cd concentrations of sphalerite in this deposit.It is noted that the bottom and top sphalerites from the strata-bound orebodies document contrasting Zn and S isotopic compositions which correspond to the Zn and S isotopic characteristics of basement rocks and host rocks,respectively.Therefore,the mixing of two-source fluids with distinct Zn-S isotopic signatures was responsible for the spatial variations of Zn-S isotopic compositions of sphalerite from the Wusihe deposit.The fluids from basement rocks are characterized by relatively lighter Zn(~0.2‰)and S(~5‰)isotopic compositions while the fluids from host rocks are marked by relatively heavier Zn(~0.6‰)and S(~15‰)isotopic compositions.

Climatological analysis of the seeing at Fuxian Solar Observatory

There is a significant seasonal variation in the seeing of Fuxian Solar Observatory(FSO). The seeing in summer and autumn is better than that in winter and spring. The overall seeing is divided into the boundary layer seeing and free atmosphere seeing to investigate the climatic phenomena or meteorological events that might lead to seasonal variation in the seeing. The overall seeing was measured by the solar difference image motion monitor(SDIMM). The boundary layer seeing is calculated from the temperature difference between air and water. The analysis results show that the seasonal variation in seeing is caused by the alternation of subtropical high and westerly jet. The decrease of seeing in winter and spring at FSO is probably related to the westerly jet. A complete analysis of the seeing at FSO is given in this paper. It is also the first time to describe FSO's boundary layer seeing and its measurement method.

A Preliminary Review of the Metallogenic Regularity of Nickel Deposits in China

The nickel deposits mainly distributed in 19 provinces and autonomous regions in China are 339 ore deposits/occurrences, including 4 super large-scale deposits, 14 large-scale deposits, 26 middle- scale deposits, 75 small-scale deposits, and 220 mineralized occurrences. The prediction types of mineral resources of nickel deposits are magmatic type, marine sedimentary type and regolith type. The formation age is from the Neoarchean to the Cenozoic with two peaks in the Neoproterozoic and the late Paleozoic. The nickel deposits formed in the Neoproterozoic are located on the margin of the North China Block and Yangtze Block, and those formed in the late Paleozoic are mainly distributed in the Central Asian Orogenic Belt （CAOB）, Emeishan and the Tarim Large Igneous Provinces （LIPs）. Magmatic nickel deposits are mainly related with broken-up continental margin, post-collision extension of the orogenic belt and mantle plume. According to different tectonic backgrounds and main characteristics of magmatism, the Ni-Cu-Co-PGE metallogenie series types of ore deposits related with mantle-derived mafic-ultramafic rocks can be divided into 4 subtypes： （1） the Ni-Cu-Co- PGE metallogenic series subtype of ore deposits related with mantle-derived mafic-ultramafic rocks in the broken-up continental margin, （2） the Ni-Cu-Co-PGE metallogenic series subtype of ore deposits related with mantle-derived mafic-ultramafic rocks in mantle plume magmatism, （3） the Ni-Cu-Co- PGE metallogenic series subtype of ore deposits related with mantle-derived mafic-ultramafic rocks in the subduction of the orogenic belt, and （4） the Ni-Cu-Co-PGE metallogenic series subtype of ore deposits related with mantle-derived mafic-ultramafic rocks in post-collision extension of the orogenic belt. We have discussed in this paper the typical characteristics and metaliogenic models for Neoproterozoic Ni-Cu-（PGE） deposits related with broken-up continental margin, Cambrian marine sedimentary Ni-Mo-V deposits related with black shale, early Permian Ni-Cu deposits related with post-collision extension of the orogenic belt, late Permian Ni-Cu-（PGE） deposits related with Large Igneous Provinces （LIPs）, and Cenozoic Ni-Au deposits related with regolith. The broken-up continental margin, mantle plume and post-collision extension of the orogenic belt are important ore- forming geological backgrounds, and the discordogenic fault, mafic-ultramafic intrusion, high MgO primitive magma （high-MgO basaltic magma）, deep magmatism, sulfur saturation and sulfide segregation are 6 important geological conditions for the magmatic nickel deposits.

Identifying the leucogranites in the Ailaoshan-Red River shear zone:Constraints on the timing of the southeastward expansion of the Tibetan Plateau

The uplift of the Tibetan Plateau significantly affected the global climate system.However,the timing of its uplift and the formation of its vast expanse are poorly understood.The occurrence of two types of leucogranites(the two-mica leucogranites and garnet-bearing leucogranites) identified in the Ailaoshan-Red River(ASRR) shear zone suggests an extension event in the southeastern Tibetan Plateau.The age of these leucogranites could be used to constrain the timing of uplift and southeastward expansion of the plateau.Petrography,geochronology and geochemistry investigations,including Sr-Nd isotope analysis,were conducted on the two-mica leucogranites and garnet-bearing leucogranites from the ASRR shear zone.LA-ICP-MS zircon U-Pb dating indicates that these rocks were emplaced at ~27 Ma,implying that the Tibetan Plateau had already achieved maximum uplift prior to the late Oligocene.It subsequently started to expand southeastward as a result of crustal flow.Compared to classic metapelite-derived leucogranites from Himalaya,the two-mica leucogranites show high K_2 O/Na_2 O(1.31-1.92),low Rb/Sr,CaO,lower ^(87)Sr/^(86)Sr ratios(0.7089-0.7164) and higher ε_(Nd)(t)(-8.83 to-3.10).This whole-rock geochemical characteristics likely indicates a mixing source origin,composed predominantly of amphibolite with subordinated metapelite,which is also evidenced by ^(87)Sr/^(86)Sr vs.ε_(Nd)(t) diagram.However,The garnetbearing leucogranites with high SiO_2 contents(72.25-74.12 wt.%) have high initial ^(87)Sr/^(86)Sr ratios(0.7332-0.7535) and low ε_(Nd)(t)(-16.36 to 18.98),indicating that they are derived from the source comprised of metapelite and results of fluexed muscovite melting under lower crustal level,which is also evidenced by the Rb-Sr-Ba systematics.These leucogranites formed from partial melting of the thickened lower crust,which resulted in the formation of granitic melt that weakened the crust.The weakened crust aided the left-lateral strikeslip movement of the ASRR shear zone,triggering the escape of the Indochina terrane in the southeastern Tibetan Plateau during the late Oligocene.

Syntactic Characteristics and a Smart Construction Mechanism for Thematic Map Symbols

The construction of thematic map symbols is a very complex and intellectually demanding process,but thematic symbols can be automatically generated and easily shared on the web using the syntactic structure of semantic symbols.In this paper,the symbol types,inner structure,and design pattern are discussed.A syntactic construction theory based on letter (thematic maps primitive)-word (single thematic symbol)-sentence (combined symbols or complex symbols) structure model is proposed to automate the construction of thematic map symbols.As a result of this research,symbols can be defined using cartographic primitives which are arranged according to syntactic principles.A semiotic model and word-centered construction theory can be integrated into interactive cartography as represented by the technology of Internet.Finally,the concepts and schema of this theory are discussed,and some examples are presented based a web thematic cartographic system to verify its utility.

Early Cretaceous transpressional and transtensional tectonics straddling the Sulu orogenic belt,East China

The Sulu orogenic belt(SOB)separates the North and South China blocks in East Asia and formed during Triassic continent-continent collision.However,late Mesozoic post-collisional exhumation is poorly understood due to lack of surface evidence for Paleo-Pacific subduction and associated effects.This paper interprets the tectonic history of the SOB using detrital zircon age data from Early Cretaceous sedimentary units along with previously published geochronologic and geochemical data to reconstruct sedimentological and tectonic history.Detrital zircon age distributions obtained from sedimentary units include a 2.0 Ga subpopulation that appears only in turbidite units to the southeast.This sediment probably derived from the Yangtze Block.Terrestrial facies from the Jiao-Lai basin to the northwest appear to derive from the North China Block.Geochronologic and geochemical data indicate that Early Cretaceous,post-collisional volcanism was compositionally bimodal(mafic-felsic)with associated intrusive activity that peaked at 120 Ma.Seismic images of northerly regions of the study area indicate this occurred in an extensional setting.Sedimentary facies and field structural analyses revealed an unconformity interpreted to reflect rapid uplift with NW SE compression to the south.Given observed sinistral movement along the Tan-Lu fault,we interpret northwest and southeast regions of the SOB as experiencing transtensional and transpressional tectonics,respectively,driven by continuous subduction of the Paleo-Pacific Plate.Intrusion of the Late Yanshannian granitoids marked the final formational stage of this unique tectonic setting.

Livelihood Capital and Livelihood Diversification for Different Farmers in Yuanjiang Dry-Hot River Valley

Under the analytical framework of sustainable livelihoods,we establish the evaluation indicator system for farmers' livelihood capital,to evaluate the current livelihood capital and livelihood diversification for different farmers in the Dai nationality region of Xinping County in the Yuanjiang dry-hot river valley area,and discuss the relationship between livelihood capital and livelihood diversification. Studies have shown that the mode dominated by agriculture,supplemented by non-agricultural activities,combined with breeding,is the commonly used livelihood strategy for farmers in this region. As farmers change from pure agriculture to non-agriculture,their total livelihood capital and nonagricultural livelihood diversification index will increase,while agricultural livelihood diversification index will decrease. In the meantime,their livelihood activities gradually shift from agricultural to non-agricultural ones,which is mainly reflected in the combination of both agricultural and non-agricultural activities. Regression analysis on livelihood capital and livelihood diversification shows that natural and physical capital is the basis of realizing agricultural livelihood diversification. Farmers with rich natural and physical capital will prefer agricultural livelihood strategies. While financial and human capital is the driving force for farmers' transition from pure agriculture to non-agriculture.

Spatial Distribution of Natural Villages Surrounding Plateau Lakes: A Case Study of the Yilong Lake in Yunnan

The study of the spatial distribution of natural villages is what local studies, cultural studies, urban and rural planning, and tourism planning need. In the context of gradually extinct natural villages, research on the characteristics analysis and protection of natural villages is of great significance. With the aid of the Arc GIS spatial analysis technology, it was concluded that terrain, traffic, and social economy were important factors influencing the distribution of the natural villages in the study area, so as to provide a technical reference for relevant local administrative departments to construct a livable ecological environment.

U-Pb Geochronology, Elemental and Sr-Nd Isotopic Geochemistry of the Houyaoyu Granite Porphyries： Implication for the Genesis of Early Cretaceous Felsic Intrusions in East Qinling

The Early Cretaceous Houyaoyu granite porphyries are located in the south margin of the North China Craton. Field observations, petrography, geochronology, major and trace elemental and Sr-Nd isotopic compositions are reported to elucidate the genesis of the Houyaoyu granite porphyries. SIMS zircon U-Pb analyses for the Houyaoyu granite porphyries yield two concordant ages of 133.2±2.3 （2σ） and 131±1.1 （2σ） Ma, respectively. Major and trace elemental compositions indicate that these porphyries are high-K I-type granites with high contents of SiO2, K20, Rb, U, Pb, low Nb, Ta, Ti, and P. Initial S：Sr/S6Sr ratios range from 0.708 3 to 0.709 7, and εNd（t） values range from -9.13 to -12.3, with corresponding two-stage depleted-mantie Nd model ages （T2DM） varying from 1.57 to 1.91 Ga. This suggests that the Houyaoyu granite porphyries were predominantly derived from ancient lower conti- nental crust, with minor involvement of mantie-derived components. On the basis of the tectonic evolution of the Qinling Orogen and geochemical characteristics of the Houyaoyu granite porphyries, it is proposed that they were formed in an extensional tectonic setting related to lithospheric destruction of the North China Craton, and produced Mo and Pb-Zn mineralization in East Qinling Orogen. KEY WORDS： East Qinling, granite porphyries, ancient lower continental crust, destruction of North China Craton.

Variation in transboundary flow of Nujiang River and its correlation with summer monsoon under the effect of the Longitudinal Range-Gorge

在在纵的范围峡(LRG ) 的地形学的效果下面的 Nujiang 河 transboundary 流动和夏天季风活动的变化之间的关系被检验。学习基于观察的河流动数据，和他们与环境预言( NCEP )的国家中心和大气的研究( NCAR )的国家中心的重新分析的 U/V 风领域的关联的统计分析，并且国家海洋、大气的管理( NOAA )的出去的 Longwave 放射( OLR )的数据。transboundary 河流动主要被集中在，这被结束湿或雨季(从 5 月到 10 月) ，特别地在夏天或洪水季节(从 6 月到 8 月) 。有一个清楚的趋势让 transboundary 河流动自从 1970 年代，与时间增加，自从 1980 年代特别地明显。由于地形学的东方西方障碍和 LRG 的纵贯的走廊效果，夏天河流动变化大部分与风被相关在高、低的高度南方、在北方。相反，河流动变化显然与风被相关仅仅在高高度，不是在低高度在东方、西。在 OLR 和河流动变化之间的否定关联也是明显的。这些关系是用索引在这篇论文建议了的二夏天季风描述的份量上。索引 MI 2 包括动态并且 thermodynamical 在 Nujiang 河盆的 LRG 区域完成并且给 transboundary 河流动变化的一个通常好的代表。更大的 MI 2 代表更强壮的夏天季风活动和更高的 transboundary 河流动，当更小的 MI 2 建议更弱的季风循环和更低的水流动时。

Geochronological and Geochemical Constraints on the Petrogenesis of Early Paleoproterozoic(2.40–2.32 Ga) Nb-Enriched Mafic Rocks in Southwestern Yangtze Block and Its Tectonic Implications

Recent geological survey has identified the Early Paleoproterozoic meta-mafic intrusions in the southwestern Yangtze Block.We present geochronological,whole-rock geochemical and Nd isotopic data for these meta-mafic rocks to better address the tectonic evolution of the Yangtze Block during the Early Paleoproterozoic Period.Geochronological data show that the meta-mafic rocks have zircon ages of 2 395-2 316 Ma.They have high TiO_2 contents of 1.40 wt.%-3.66 wt.% and Nb concentrations of 13.7 ppm-45.5 ppm,thus aregrouped as Nb-enriched mafic rocks.These mafic rocks are characterized by tholeiitic compositions with enrichment of LREEs and LILEs,and can be divided into two groups.Group 1 samples display E-MORB-like geochemical characteristics.Group 2 samples have positive ENd(t) values of 4.0-5.0.Geochemical data indicate that all meta-mafic rocks were likely derived from a depleted asthenospheric mantle.REE modeling indicates lower degree of partial melting for Group 2 samples(3%-10%) relative to Group 1 samples(15%-20%).Taking into account contemporaneous post-collisional granitoids in southwestern Yangtze Block,we propose that these meta-mafic rocks were formed in a post-collisional extension setting.These meta-mafic rocks can be compared with those in Africa,South America and Europe,and might be linked with the Arrowsmith orogenic belt.

Multi-object approach and its appfication to adaptive water management under climate change

This paper addresses issues on adaptive water management under the impact of climate change. Based on a set of comprehensive indicators of water system, a decision making approach of multi-objects is developed and applied to quantify water adaptive man- agement for the demands of water sustainable use, water environmental protection and eco-water requirement under the climate change. For this study in China, two key indicators are proposed, namely （1） the water resources vulnerability （V） that was represented by inte- grated sensitivity （S） and resilience （C） of climate change impact on water resources, and （2） the sustainability of socio-economy and water environment, marked by DD, that is integrated scaler of socio-economic development （EG） based on the amount of GDP and the water en- vironment and relative eco-system quality （LI）. To find a reasonable solution for adaptive water management, a multi-objective decision making model of adaptive water management is further developed and the multi-objective model was transformed into an integrated single optimization model through developing an integrated measure function, called as VDD=DD/V. This approach has been applied to adaptive water resources planning and management for case study of China with new policy, called as the strict management of water resources based on three red line controls, i.e., the control of total water use by the total water re- sources allocation, the control of lower water use efficiency by the water demand manage- ment and the control of the total waste water load by water quality management in the East- ern China Monsoon Region that covers major eight big river basins including Yangtze River, Yellow River, Haihe River and Huaihe River. It is shown that the synthetic representation of water resource vulnerability and socio-economic sustainability by the integrated objective function （VDD） and integrated decision making model are workable and practicable. Adaptive management effect of the criterion compliance rate and water use efficiency are more ap- preciable through new water policy of the three red line controls, which can reduce 21.3% of the water resources vulnerability （V） and increase 18.4% of the sustainability of socio- economy and water environment （DD） for the unfavorable scenario of climate change in2030.

Martian magnetic field properties before the termination of its core dynamo

Observed Martian crustal magnetism shows that the Mars does not possess a global-scale,dynamo-driven intrinsic magnetic field.In addition,the remnant field at the surface is hemi-spherically asymmetric.Our earlier simulation results suggest that the Martian dynamo could be sub-critical near its end(the energy required to sustain a subcritical dynamo is less than that to excite the dynamo)and the generated field morphology is non-dipolar.We further the study to examine the characteristics of the magnetic field via Empirical Orthogonal Function(EOF)analysis on the subcritical dynamo solutions with the Rayleigh number Rth = 2480(below the critical point for the onset of the Martian dynamo).Our results show that the magnetic field is dominantly equatorial dipolar.Reversals and excursions occur frequently,and the magnetic dipole moment does not vary monotonically in time.