Metallogenic Model of Bauxite in Central Guizhou Province:an Example of Lindai Deposit

The bauxites in central Guizhou are hosted by the Lower Carboniferous Jiujialu Formation.Geochemistrial characteristics of the Lindai bauxite deposit indicate that the underlying Shilengshui Formation dolomite is the precursor rock of mineral resources.Weathering simulation experiments show that Si is most likely to migrate with groundwater,the migration rate of which is several magnitude higher than Al and Fe under nature conditions （pH=3-9）.The neutral and acid nonreducing condition is the most conducive to the Al rich and Si removal,while the acid reducing conditions is the most conducive to the Al rich and Fe removal.In the process of bauxite formation,coal beds overlying the Al-bearing rock series or other rock formation rich in organic materials can produce acid reducing groundwater,which are important for the bauxite formation.Finally,propose the metallogenic model of the bauxite in central Guizhou Province and put forward three new words which are ＂original bauxite material＂,＂bauxite material＂ and ＂original bauxite＂.

Development Plan for Under- forest Economy of Henan Province Based on Central Plains Economic Region

Firstly,this paper analyzed current situations,major practice and existing problems of under-forest economy in Henan Province.Then,it made an in-depth discussion of guiding thought,principle and objectives,construction task and safeguarding measures of the underforest economic development plan. Besides,it analyzed benefits of the under-forest economic development plan. By 2017,the area of underforest economic land will reach 1. 60 million hm2,create output value of 155. 2 billion yuan( accounting for more than 20% of forest output value),provide 3. 27 million jobs,and will greatly increase ecological carrying capacity of construction and development of the Central Plains Economic Region( CPER).

Paleotectonic Setting of Dongyan Group of Middle and Upper Proterozoic in Central Fujian Province

The central Fujian Province, situated on the juncture of paleo-uplift of Wuyishan, Yongmei Late Paleozoic depression and the eastern volcanic rift-faulting zone, is mainly composed of the outcropped metamorphic basements in the Middle-Late and Early Proterozoic, which constitute two upper and lower giant thick formations of Precambrian volcanic-sedimentary cycles, respectively. The formation of Dongyan Group is an important Middle-Upper Proterozoic component, and the Dongyan Group is directly related to massive sulfide deposit in this area. In recent years, plenty of lead, zinc, copper, silver and gold deposits have been found and explored. The Precambrian paleorift setting of the central Fujian Province served as a favorite metallogenic background for the formation of large- and superlarge-scale volcanic massive sulfide (VMS) lead and zinc polymetal deposits. The Dongyan Group consists chiefly of a set of ancient volcanic sedimentary formations that are composed mainly of greenschist. Its major lithologic types comprise greenschist, marble, quartzite and granofels class including various components. The metamorphic rocks of Dongyan Group are the main composition of Middle and Upper Proterozoic volcanic-sedimentary cycle. The original rock of Dongyan Group, a stable rock association, is volcanic sedimentation and normal marine sedimentation. But the original volcanic rocks, basic and acid, are bimodal. The volcanic rocks were formed in the extensional continental rift setting.

Crustal velocity structure of central Gansu Province from regional seismic waveform inversion using firework algorithm

The firework algorithm（FWA） is a novel swarm intelligence-based method recently proposed for the optimization of multi-parameter, nonlinear functions. Numerical waveform inversion experiments using a synthetic model show that the FWA performs well in both solution quality and efficiency. We apply the FWA in this study to crustal velocity structure inversion using regional seismic waveform data of central Gansu on the northeastern margin of the Qinghai-Tibet plateau. Seismograms recorded from the moment magnitude（MW） 5.4 Minxian earthquake enable obtaining an average crustal velocity model for this region. We initially carried out a series of FWA robustness tests in regional waveform inversion at the same earthquake and station positions across the study region,inverting two velocity structure models, with and without a low-velocity crustal layer; the accuracy of our average inversion results and their standard deviations reveal the advantages of the FWA for the inversion of regional seismic waveforms. We applied the FWA across our study area using three component waveform data recorded by nine broadband permanent seismic stations with epicentral distances ranging between 146 and 437 km. These inversion results show that the average thickness of the crust in this region is 46.75 km, while thicknesses of the sedimentary layer, and the upper, middle, and lower crust are 3.15,15.69, 13.08, and 14.83 km, respectively. Results also show that the P-wave velocities of these layers and the upper mantle are 4.47, 6.07, 6.12, 6.87, and 8.18 km/s,respectively.

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.

Effects of Land Use Change on Eco-environment in Hilly Area of Central Sichuan Basin——A Case Study of Yanting County, Sichuan Province

With the artificial alder and cypress mixed forest being planted, there has been a marked land use change since 1970s' in Hilly Area of Central Sichuan Basin, China. Data from meteorological observations or posts operated over long time, measurement and calculation of NPP (net primary production) and biomass of biological community, and analysis of soil organic matter content show that the artificial alder and cypress mixed forest has outstanding eco-environmental effect: adjusting local climate, raising soil fertility, alleviating menace of drought, and raising NPP and biomass of biological community. It is very beneficial for improving ecological environment to afforest artificial alder and cypress mixed forest in populous Hilly Area of Central Sichuan Basin, China. Key Words: land use/land cover change (LUCC); eco-environmental effect; Hilly Area of Central Sichuan Basin; the artificial alder and cypress mixed forest

REE geochemistry of the Zhoutan Group metasedimentary rocks in central Jiangxi Province,Southeast China

Detailed REE and trace elements geochemical studies of the Zhoutan Group metasedimentary rocks in central Jiangxi Province, China, and rock-forming minerals such as garnet were conducted and the results showed that the REEs are partly present in the rock-forming minerals and are dominantly contained in the lattice of accessory minerals. In the process of metamorphism the REEs between garnet porphyroblast and rock and the partitioning of REEs between garnet and the host rock is obviously controlled by the chemical composition of the system. The REEs compositions of metamorphic veins and their minerals display remarked lanthanide tetrad effects and the element pairs Zr-Hf, Y-Ho, Pb-Nd and U-Th have also experienced a certain degree of fractionation with respect to the metasedimentary rocks and they can be used as discriminating indicators to some extent for the occurrence of fluid processes in the process of metamorphism of the Zhoutan Group.

Elemental geochemistry and Nd isotopic characteristics of the metasedimentary rocks from the metamorphic belt in central Jiangxi: Provenance and tectonically environmental constraints

The metamorphic belt in central Jiangxi, located in the compound terrain within the Cathaysia, Yangtze Block and Caledonian fold zone of South China, is composed dominantly of meta-argillo-arenaceous rocks, with minor amphibolite. These rocks underwent amphibolite-facies metamorphism. The meta-argillo-arenaceous rocks show large variations in major element composition, but have similar REE patterns and trace element composition, incompatible element and LIE enrichments [high Th/Sc ({0.57}-{3.59}), La/Sc ({1.46}-{12.4}), La/Yb ({5.84}-{19.0})] and variable Th/U ratios, with ΣREE=129-296μg/g, δEu={0.51}-{0.86}, and (La/Yb)-N={3.95}-{12.9}. The Nd isotopic model ages t-{DM} of these rocks vary from 1597 to 2124 Ma. Their {}+{143}Nd/+{144}Nd values are low [ε-{Nd}(0)={-11.4} to {-15.8}]. Some conclusions have been drawn as follows: (1) The metamorphic rocks in central Jiangxi Province are likely formed in a tectonic environment at the passive continental margin of the Cathaysia massif. (2) The metamorphosed argillo-arenaceous rocks are composed dominantly of upper crustal-source rocks (Al- and K|rich granitic or/and sedimentary rocks of Early Proterozoic), which experienced good sorting, slow deposition and more intense chemical weathering. (3) According to the whole-rock Sm-Nd isochron ages (1113±49 to 1199±26 Ma) of plagioclase-amphibole (schist) and Nd isotopic model age t-{DM} (1597-2124 Ma) of meta-argillo-arenaceous rocks, the metamorphic belt in central Jiangxi Province was formed during the Middle Proterozoic (1100-1600 Ma).

Mesorif Gabbros(External Rif, North Morocco): Ophiolitic Suture Witness or a “Newly Discovered” Manifestation of the Central Atlantic Magmatic Province?

The Rif Mountain located in Northern Morocco represents the westernmost extremity of the Peri-Mediterranean Alpine orogenic system.This belt is classically subdivided into:1)Internal zones(or Internal Rif which is an allochthonous metamorphic domain known worldwide thanks to the presence of large peridotite outcrops);2)flysch zones(sediments corresponding to the original cover of the Maghrebian Tethys);and 3)External zones(or External Rif representing the North African margin remnants).The External Rif is itself subdivided into Prerif,Mesorif and Intrarif domains from the South to the North and is composed by Upper Triassic to Cenozoic sediments structured in a nappe stack.Mafic rock intrusions were reported in this External Rif since the preliminary geological studies even if they were wrongly mapped as"granites".Later careful fieldwork and mapping studies specified nevertheless their gabbroic nature.A more recent petrological and geochemical study of a few outcrops of those gabbroic intrusions conducted the corresponding authors,encouraged by the presence of ultramafic rocks(Beni Malek serpentines)in the eastern part of the External Rif to consider those gabbros as oceanic and so,associated to"an ophiolitic suture".Nevertheless,a recent and extended survey on the architecture and the rifting history of the Mesozoic margin of the Maghrebian Tethys focusing mainly on the Mesorif domain favor another interpretation.The detailed petrography of those mafic intrusions(mainly gabbros+dolerites and rarely extrusive rocks);their geochemical fingerprints and mainly their geochronological data(ages around 200 Ma based on U-Pb zircon LA-ICP dating)all together indicate clearly that those mafic intrusions are rather a"newly discovered"manifestation of the Central Atlantic Magmatic Province activity"CAMP"in the External Rif belt.The CAMP magmatism has been largely well described and characterized in all the other geological domains of Morocco(Anti-Atlas,High Atlas,Middle Atlas and Meseta)but never described until the date in the Rif belt which highlights the importance of the results reported here.

Environmental Implication of Subaqueous Lava Flows from A Continental Large Igneous Province: Examples from the Moroccan Central Atlantic Magmatic Province(CAMP)

The Early Jurassic volcanic sequence of the Central Atlantic Magmatic Province(CAMP)of Morocco is classically subdivided into four stratigraphic units:the Lower,Middle,Upper and Recurrent Formations separated

THE MECHANICAL RELATIONSHIP TO THE FORMATION AND DISTRIBUTION OF THEBURIED HILLS AND THE DEEP-SEATED FRACTURAL ZONE IN THE DIWA-TYPE FAULTED BASIN IN CENTRAL HEBEI PROVINCE,CHINA

The author proves the existence and movement of a deep-seated fraetural Zone located in the eenter zone of the diwa-type faulted basin in central Hebei Province. This deep-seated fraeturai zone tending in NNE direction is a structural effect of the mtodle East Asin Grustobody in the Mexozoic-Cenozoic. This paper will diseuss the formation, evolution and the meehanism of the deep-seated fraetural zone, faulted basin and the buried hills as well as their relationships. The uthor expounds that the deep geological process is the major factor of the structural effect.

Structural Origin of the Red-Ribbon Style Iron Ores in the Xinyu Iron Deposit,Central Jiangxi Province

The Xinyu iron deposit, located in central Jiangxi Province, is one of the most important BIF-type deposits in China. It is hosted in the Late Proterozoic volcanic- sedimentary rocks, which are composed of sericite- chlorite pyhllite, magnetite-bearing chlorite phyllite or schist, magnetite quartzite, and schist （Yu et al., 1989; Zeng et al., 2011）.

Geochronology,geochemistry and geodynamics implications of Middle Triassic garnet-bearing muscovite monzogranite in central Jilin Province

Zircon LA-ICP-MS U-Pb geochronology and geochemical analyses are undertaken for the garnet-bearing muscovite monzogranite in Yitong area,central Jilin Province. The formation age and petrogenesis of the granite are determined,and the regional tectonic background is discussed. Zircons from the granite are euhedral-subhedral in shape,and display fine-scale oscillatory growth zoning,indicating a magmatic origin. LAICP-MS zircon U-Pb dating result indicates that the garnet-bearing muscovite monzogranites formed in the middle Triassic( 243 Ma). The garnet-bearing muscovite monzogranites have high SiO_2( Si O2= 74. 1%--76. 49%),rich aluminum( Al_2O_3= 14. 47%--14. 68%) and alkali( Na_2O + K_2O = 4. 31%--7. 9%),low Fe_2O_3 T and MgO( MgO = 0. 1%--0. 13%,Fe_2O_3 T = 0. 46%--1. 02%). The ratio of CaO/Na_2O is between 0. 17--0. 21. The garnet-bearing muscovite monzogranites in Yitong region are relatively enriched in light rare earth elements( LREEs) and large ion lithophile elements( LILEs),and depleted of heavy rare earth elements( HREEs) and high field strength elements( HFSEs). They are characterized by high Sr and Ba,poor Rb and Y,and negative Eu abnormally( δEu = 0. 48--0. 62),with Rb/Sr < 1. The ε_(Hf)( t) values and T_(DM2) of zircons range from + 6. 10 to + 8. 00 and from 725 Ma to 814 Ma,respectively. The above features indicate that garnet-bearing muscovite monzogranites in Yitong area were derived from partial melting of metasedimentary rock.These granites have high Sr/Y ratios,which suggest they formed in a thickened continental crust. Combined with the coeval granitic rocks in central Jilin Province,we suggested that a significant collisional and thickening event took place during the Middle Triassic.

Reassessment of petrogenesis of Carboniferous—Early Permian rift-related volcanic rocks in the Chinese Tianshan and its neighboring areas

The Carboniferous-Early Permian rift-related volcanic successions, covering large areas in the Chinese Tianshan and its adjacent areas, make up a newly recognized important Phanerozoic large igneous province in the world, which can be further divided into two sub-provinces： Tianshan and Tarim. The regional unconformity of Lower Carboniferous upon basement or pre-Carboniferous rocks, the ages （360--351 Ma） of the youngest ophiolite and the peak of subduction metamorphism of high pressure-low temperature metamorphic belt and the occurrence of Ni-Cu-bearing mafic-ultramafic intrusion with age of ~352 Ma and A-type granite with age of ~358 Ma reveal that the final closure of the Paleo-Asian Ocean might take place in the Early Mississippian. Our summation shows that at least four criteria, being normally used to identify ancient asthenosphere upwelling （or mantle plumes）, are met for this large igneous province： （1） surface uplift prior to magmatism; （2） being associated with continental rifting and breakup events; （3） chemical characteristics of asthenosphere （or plume） derived basalts; （4） close links to large-scale mineralization and the uncontaminated basalts, being analogous to those of many ＂ore-bearing＂ large igneous provinces, display Sr-Nd isotopic variations between plume and EMI geochemical signatures, These suggest that a Carboniferous asthenosphere upwelling and an Early Permian plume played the central role in the generation of the Tianshan--Tarim （central Asia） large igneous province.

Geochronology and geochemistry of the Hekoulinchang Sn-Pb-Zn-Ag polymetallic deposit(73240 t) in Heilongjiang Province, China

The Hekoulinchang Sn-Pb-Zn-Ag polymetallic deposit(20000 t Sn at 0.27%,236 t Ag at 122.89 g/t,15000 t Pb at 0.84%,and 38000 t Zn at 1.43%)is located in the Wandashan Terrane of the easternmost segment of the Central Asian Orogenic Belt.The timing of Sn-Pb-Zn-Ag polymetallic mineralization remains unclear due to a lack of precise isotope dating directly conducted on ore minerals.The authors herein report that the LA-ICP-MS U-Pb ages of cassiterite and zircon from the granite porphyry in the Hekoulinchang Sn-Pb-Zn-Ag polymetallic deposit are 101.4±7.9 Ma and 115.4±1.0 Ma,respectively,indicating that Sn mineralization and magmatism occurred during the Early Cretaceous.The granite porphyry belongs to the subalkaline series peraluminous I-type granites that are depleted in Nb,Ta,and Ti and enriched in Rb,Th,U,and Pb.TheεHf(t)values of the granite porphyry range from 0.9 to 7.4,with an average of about 5.6 and two-stage model ages(T_(DM2))of 705–1116 Ma,with an average age of 819 Ma.The ε_(Nd)(t)values of the apatites are–1.60–0.45,with an average of–0.9,and two-stage model ages(T_(DM2))of 872–1040 Ma,with an average age of 983 Ma.The Nd-Hf isotope data indicate that the magma may have been derived from the partial melting of juvenile crustal material.

An Empirical Analysis of the Export Competitiveness of Agricultural Products in Hubei Province Based on Inter-provincial Comparison

With the six provinces of Central China and China's six major provinces of exporting agricultural products as the reference objects,this paper uses revealed comparative advantage index and export growth advantage index to perform the empirical analysis and comparison on the export competitiveness of agricultural products in Hubei Province,and finally makes the corresponding policy recommendations in order to enhance the export competitiveness of agricultural products in Hubei Province.

中部六省经济增长与工业三废脱钩关系

基于Tapio脱钩弹性系数模型,选取工业增加值、人均GDP、工业废水、工业废气、工业固体废弃物排放量等5个指标,对中部六省2005—2019年工业三废排放与工业增加值、人均GDP增长的脱钩关系进行实证研究。结果表明:时间上看,中部六省工业增加值与工业三废排放和人均GDP增长与工业三废排放的脱钩弹性系数无时序规律,但整体脱钩关系向绝对脱钩演变;工业增加值与工业三废排放量大部分处于脱钩状态,但状态不稳定,仍有少部分非脱钩状态存在;人均GDP增长与工业三废排放脱钩关系大部分处于相对脱钩和绝对脱钩状态,少部分呈扩张负脱钩和增长连结状态。空间上看,湖南省是两组脱钩关系中表现最优的省份,山西省是两组脱钩关系中表现最差的省份。

中部六省乡村教师队伍建设政策文本分析

优化乡村教师队伍建设政策对缩小城乡教育差距、推动地区高质量发展具有重要意义。我国中部六省在乡村教师队伍补充、保障和培养等方面有很多共性政策,对提高乡村教师幸福感、留住乡村教师和提升乡村教师教育教学能力等方面发挥了积极作用,但在加大对师范院校和师范类专业的支持力度、加强对师范生乡村教育实习过程监控、提高对非师范专业毕业人员的招聘要求、对“校联体”学校实行整体评价、实行乡村教师“鹊桥工程”、培训内容聚焦留守儿童教育、复式教学等方面还可继续着力。