The Panzhihua mafic intrusion,which hosts a world-class Fe-Ti-V ore deposit,is in the western Emeishan region,SW China.The formation age(~260 Ma),and Sr and Nd isotopes indicate that the Panzhihua intrusion is part of...The Panzhihua mafic intrusion,which hosts a world-class Fe-Ti-V ore deposit,is in the western Emeishan region,SW China.The formation age(~260 Ma),and Sr and Nd isotopes indicate that the Panzhihua intrusion is part of the Emeishan large igneous province and has little crustal contamination.To assess ore genesis of the Panzhihua Fe-Ti-V ore deposit,two different models have been provided to explain the formation,namely silicate immiscibility and normal fractional crystallization.Silicate immiscibility occurring around 1,000℃at the late stage of basaltic magma evolution argues against the silicate immiscibility model.Apatite-hosted melt inclusion research indicates that silicate immiscibility occurred at the late stage of Panzhihua magma evolution,which may not have offered potential to form such large ore deposits as Panzhihua.Alternatively,continuous compositional variations of the Panzhihua intrusion and calculations using thermodynamic modelling software support the hypothesis that the Panzhihua deposit was formed by normal fractional crystallization.Reciprocal trace element patterns of the Panzhihua intrusion and nearby felsic rocks also coincide with the fractional crystallization model.Normal fractional crystallization of high-Ti basaltic magma played a key role in the formation of the Panzhihua Fe-Ti-V ore deposit.展开更多
The permittivity of low grade Panzhuhua ilmenite ore at 2.45 GHz in the temperatures from 20 ℃ up to 100 ℃ was measured using the technology of open-ended coaxial sensor combined with theoretical computation. The re...The permittivity of low grade Panzhuhua ilmenite ore at 2.45 GHz in the temperatures from 20 ℃ up to 100 ℃ was measured using the technology of open-ended coaxial sensor combined with theoretical computation. The results show that both the real （ε′） and imaginary （ε′） part of complex permittivity （ε′-jε′） of the ilmenite significantly increase with temperature. The loss tangent （tanδ） is a quadratic function of temperature, and the penetration depth of ilmenite decreases with temperature increase from 20 ℃to 100 ℃ The increase of the sample temperature under microwave radiation displays a nonlinear relationship between the temperature （T） and microwave heating time （t）. The positive feedback interaction between complex permittivity and sample temperature amplifies the interaction between ilmenite and the microwave radiation. The optimum dimensions for uniform heat deposition vary from 10 cm to 5 cm （about two power penetration depths） in a sample being irradiated from both sides in a 2.45 GHz microwave field when temperature increases from room temperature to 100 ℃展开更多
Affected by southwest monsoon moisture and topography redistribution,natural precipitation in Panzhihua had obvious difference in temporal and spatial distribution.By using precipitation data from Renhe station in Pan...Affected by southwest monsoon moisture and topography redistribution,natural precipitation in Panzhihua had obvious difference in temporal and spatial distribution.By using precipitation data from Renhe station in Panzhihua during 1965-2009,the variation characteristics of annual precipitation,flood season precipitation and seasonal precipitation were analyzed.The results showed that spring precipitation,summer precipitation,flood season precipitation and annual precipitation changed conformably and significantly since 1970s in 20th century,showing increase trend at present,while autumn precipitation showed decrease tendency.From the 10-year running mean of annual precipitation,it was found that the annual variation of precipitation resources in Panzhihua City had its own regularity,and there was a slowly decrease at present.展开更多
[Objective] This study aimed to investigate the improving effect of quick- lime on acid soil in tobacco-growing areas in Panzhihua City. [Method] The effects of four application amounts （450, 900, 1 350 and 1 800 kg/...[Objective] This study aimed to investigate the improving effect of quick- lime on acid soil in tobacco-growing areas in Panzhihua City. [Method] The effects of four application amounts （450, 900, 1 350 and 1 800 kg/hm2） of quicklime on soil nutrients and flue-cured tobacco quality were observed for two consecutive years. [Result] In acid soil, the application of quicklime significantly improved soil pH. In addition, it showed significant effects on soil nutrients, flue-cured tobacco quality, tobacco output and tobacco leaf chemical components. When the application amount of quicklime was increased to 1 350 kg/hm2, the improving effect of quick- lime on soil nutrients was best, the flue-cured tobacco yield and quality all reached the highest, and the chemical components of tobacco leaves were closest to the in- herent indicators of high-quality tobacco leaves. [Conclusion] This study will provide certain reference for accurate application of quicklime in tobacco-growing area in Panzhihua City.展开更多
The Panzhihua intrusion in southwest China is part of the Emeishan Large Igneous Province and host of a large Fe-Ti-V ore deposit.During emplacement of the main intrusion,multiple generations of mafic dykes invaded ca...The Panzhihua intrusion in southwest China is part of the Emeishan Large Igneous Province and host of a large Fe-Ti-V ore deposit.During emplacement of the main intrusion,multiple generations of mafic dykes invaded carbonate wall rocks,producing a large contact aureole.We measured the oxygen-isotope composition of the intrusions,their constituent minerals,and samples of the country rock.Magnetite and plagioclase from Panzhihua intrusion haveδ18O values that are consistent with magmatic equilibrium, and formed from magmas withδ18O values that were 1-2‰higher than expected in a mantle-derived magma.The unmetamorphosed country rock has highδ18O values,ranging from 13.2‰（sandstone） to 24.6-28.6‰（dolomite）.The skarns and marbles from the aureole have lowerδ18O andδ13C values than their protolith suggesting interaction with fluids that were in exchange equilibrium with the adjacent mafic magmas and especially the numerous mafic dykes that intruded the aureole.This would explain the alteration ofδ18O of the dykes which have significantly higher values than expected for a mantle-derived magma.Depending on the exactδ18O values assumed for the magma and contaminant, the amount of assimilation required to produce the elevatedδ18O value of the Panzhihua intrusion was between 8 and 13.7 wt.%,assuming simple mixing.The exact mechanism of contamination is unclear but may involve a combination of assimilation of bulk country rock,mixing with a melt of the country rock and exchange with CO2-rich fluid derived from decarbonation of the marls and dolomites.These mechanisms,particularly the latter,were probably involved in the formation of the Fe-Ti-V ores.展开更多
The Panzhihua gabbroic intrusion,part of the plumbing system of the Emeishan large igneous province, intruded late-Proterozoic dolomites and marls about～263 Ma ago.The dolomites in the contact aureole were converted ...The Panzhihua gabbroic intrusion,part of the plumbing system of the Emeishan large igneous province, intruded late-Proterozoic dolomites and marls about～263 Ma ago.The dolomites in the contact aureole were converted to brucite marbles and a diverse suite of forsterite,diopside and garnet skarns.The variation in mineralogy is explained in part by differences in the composition of the protolith,particularly the proportion of silica minerals and clay,and in part by transfer of elements from intruding magmas.The trace element compositions of most marbles and skarns are very similar to those of unmetamorphosed dolomites and marls,but some contain high Si,Ti,and Fe contents that are interpreted to have come from a magmatic source.Three brucite marbles sampled～10 m from the contact of the intrusion and named ＂enriched brucite marble＂ have trace element compositions very different from their dolomitic protolith：their rare earth elements are strongly enriched whereas levels of Nb-Ta,Zr-Hf and Ti are very low.These characteristics resemble those of carbonate liquid in equilibrium with silicate liquid or more probably with silicate minerals in the case of Panzhihua,a similarity we take to indicate that the sample underwent partial melting.Samples taken up to 300 m from the contact contain brucite indicating that high temperatures persisted well into the country rocks.However,other samples collected only tens of metres from the contact are only slightly recrystallized indicating that conditions in the aureole were highly variable.We suggest that temperatures within the aureole were controlled by conduction of heat from the main intrusion and by supply of additional heat from abundant small dykes within the aureole.Circulation of fluids derived from deeper levels in the aureole flushed the carbon dioxide from the dolomite,lowering temperature needed to partially melt carbonate to the temperatures attained near the intrusion.Irregular but extensive heating destabilized the carbonates of the aureole and decarbonation reactions associated with carbonate breakdown and melting emitted a large volume of CO2,with potential impact on global climate.展开更多
A sequence of gabbros showing isotropic,layered and fine-grained textures is exposed in the Nalaqing mine at the southern tip of the～260 Ma Panzhihua intrusion,SW China.The field relations,structure,texture and miner...A sequence of gabbros showing isotropic,layered and fine-grained textures is exposed in the Nalaqing mine at the southern tip of the～260 Ma Panzhihua intrusion,SW China.The field relations,structure,texture and mineralogy of the rocks indicate that the sequence represents the transition between the Lower zone and Middle zone of the intrusion.Isotropic gabbros characteristic of the Lower zone pass upward to layered gabbros of the Middle zone through a～5 m-thick microgabbro sheet,within and close to which small-scaled, concordant Fe-Ti oxide ore horizons are identified.Strong fractionation between HFSE and REE in a subset of samples is ascribed to cumulus titanomagnetite into which HFSE are preferentially incorporated over REE,as reflected in the parallel relations between Nb/La,Hf/Sm and Ti/Ti＊.Both the isotropic and layered gabbros display cumulate textures and have similar mineral compositions（Mg# of clinopyroxene =～76-79 and An59-61）,isotopic compositions[（87Sr/86Sr）i = 0.7044-0.7045 andεNd（t） = ＋2.4 to ＋3.9]and trapped liquid contents inferred from Zr abundance（～17-34 ppm）.However,there are substantial variations in elemental abundances（V,Cr and PGE） and ratios（Ti/V,La/Yb,Ba/Y and Cu/Pd） between the two types of gabbros,features that cannot be explained by cumulate formation from a common magma in a closed system.The microgabbros generally resemble high-Ti Emeishan basalts in major element compositions,but their low trace element abundances indicate some lost of residual liquid is inevitable despite rapid nucleation and cooling.Combined with available data and observations,we propose a model involving in-situ crystallization,followed by magma recharge and closed-system fractionation to explain the formation of texturally distinctive gabbros at Nalaqing and the evolution of the lower part of the Panzhihua intrusion.展开更多
Recent work on the Panzhihua intrusion has produced two separate models for the crystallisation of the intrusion：（1） low-Ti,high CaO and low H2O（0.5 wt.%） parent magma（equivalent to Emeishan low-Ti basalt） at F...Recent work on the Panzhihua intrusion has produced two separate models for the crystallisation of the intrusion：（1） low-Ti,high CaO and low H2O（0.5 wt.%） parent magma（equivalent to Emeishan low-Ti basalt） at FMQ;and（2） high-Ti,low CaO and higher H2O（＆gt;1.5 wt.%） parent magma（equivalent to Emeishan high-Ti basalt） at FMQ ＋ 1.5.Modelling of these parent magma compositions produces significantly different results. We present here detailed f（O2） and H2O modelling for average compositions of both Emeishan high-Ti and low-Ti ferrobasalts in order to constrain the effects on crystallisation sequences for Emeishan ultra-mafic -mafic layered intrusions.Modelling is consistent with numerous experimental studies on ferro-basaltic magmas from other localities（e.g.Skaergaard intrusion）.Modelling is compared with the geology of the Panzhihua intrusion in order to constrain the crystallisation of the gabbroic rocks and the Fe-Ti oxides ore layers.We suggest that the gabbroic rocks at the Panzhihua intrusion can be best explained by crystallisation from a parent magma similar to that of the high-Ti Emeishan basalt at moderate H2O contents（0.5-1 wt.%） but at the lower end of TiO2 content for typical high-Ti basalts（2.5 wt.%TiO2）. Distinct silicate disequilibrium textures in the Fe-Ti oxide ore layers suggest that an influx of H2O may be responsible for changing the crystallisation path.An increase in H2O during crystallisation of gabbroic rocks will result in the depression of silicate liquidus temperatures and resultant disequilibrium with the liquid.Continued cooling of the magma with high H2O then results in precipitation of Mt-Uv alone. The H2O content of parent magmas for mafic layered intrusions associated with the ELIP is an important variable.H2O alters the crystallisation sequence of the basaltic magmas so that at high H2O and f（O2） Mt -Uv crystallises earlier than plagioclase and clinopyroxene.Furthermore,the addition of H2O to an anhydrous magma can explain silicate disequilibrium texture observed in the Fe-Ti oxide ore layers.展开更多
Panzhihua city （26°O5＇-27°21＇N, 101°OS＇- 102°15＇E）, located in a mountainous area, is one of the large cities in Sichuan province, China. A landslide occurred in the filling body of the easte...Panzhihua city （26°O5＇-27°21＇N, 101°OS＇- 102°15＇E）, located in a mountainous area, is one of the large cities in Sichuan province, China. A landslide occurred in the filling body of the eastern part of the Panzhihua airport on October 3, 2009 （hereafter called the lo.3 landslide）. We conducted field survey on the landslide and adopted emergency monitoring and warning models based on the Internet of Things （loT） to estimate the losses from the disaster and to prevent a secondary disaster from occurring. The results showed that four major features of the airport site had contributed to the landslide, i.e, high altitude, huge amount of filling rocks, deep backfilling and great difficulty of backfilling. The deformation process of the landslide had six stages and the unstable geological structure of high fillings and an earthquake were the main causes of the landslide. We adopted relative displacement sensing technology and Global System for Mobile Communications （GSM） technology to achieve remote, real-time and unattended monitoring of ground cracks in the landslide. The monitoring system, including five extensometers with measuring ranges of 200, 450 and 7oo mm, was continuously working for 17 months and released 7 warning signals with an average warning time of about 26 hours. At 10 am on 6 December 2009, the system issued a warning and on-site workers were evacuated and equipment protected immediately. At 2：20 medium-scale collapse monitoring site, which proved the reliability pm on 7 December, a occurred at the No. 5 justified the alarm and and efficiency of the monitoring system.展开更多
Mining activities have created huge uncovered slopes, large areas of gangue ground and extensive tailings dams. This paper presents the environmental geochemistry of mining activities in Panzhihua region. The selected...Mining activities have created huge uncovered slopes, large areas of gangue ground and extensive tailings dams. This paper presents the environmental geochemistry of mining activities in Panzhihua region. The selected elements (Ti, V, Mo. Ni. Pb. Cu) show similar distribution patterns of concentration anomaly in topsoil. These concentration anomalies are located in V-Ti-magnetite slope, gangues dam and coal mine. The distinction between anthropogenic contamination and natural background is made available by the use of the enrichment factor in this study area. The anomalies of EF were smaller than that of concentration. The results from EF show that the selected elements anthropogenic pollution (EF>1) in topsoil were located in both the coal mining area and the V-Ti-magnetite mining area. In addition, the pollution sources of selected elements came from V-Ti-magnetite, slag, gangues, coal and other pollutants from mining activities.展开更多
The hydrogen reduction of Panzhihua ilmenite concentrate in the temperature range of 900?1050 °C was systematicallyinvestigated by thermogravimetric analysis (TG), X-ray diffraction (XRD) and scanning electron mi...The hydrogen reduction of Panzhihua ilmenite concentrate in the temperature range of 900?1050 °C was systematicallyinvestigated by thermogravimetric analysis (TG), X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods. It wasshown that the products of the Panzhihua ilmenite reduced at 900 °C were metallic iron and rutile. Above 1000 °C, ferrouspseudobrookite solid solution was generated. During the reduction process, element Mg gradually concentrated to form Mg-rich zonewhich can influence the metallization process. The reduction reaction proceeded topochemically and its related reduction kineticswere also discussed. The kinetics of the reduction indicated that the rate-controlling step was the diffusion process. The apparentactivation energy of the hydrogen reduction of Panzhihua ilmenite was calculated to be 117.56 kJ/mol, which was larger than that ofsynthetic ilmenite under the same reduction condition.展开更多
Objective] This study almed to expIore a suitabIe fIue-cured tobacco young seedIings cuItivation technique for tobacco-producing areas in Panzhihua. [Method] The randomized bIock design was used to conduct a two-facto...Objective] This study almed to expIore a suitabIe fIue-cured tobacco young seedIings cuItivation technique for tobacco-producing areas in Panzhihua. [Method] The randomized bIock design was used to conduct a two-factor test of fIoating pate and seedIing age. [Result] The young seedIings cuItivation technique re-duced the cuItivation cost by 76.6%; the optimum seedIing age was 45 d; the fIoat-ing pIate with specification of 595 hoIes/pIate couId best improve the cuItivation effi-ciency; and the Ieaf-uncut young seedIings cuItivation technique significantIy reduced the incidence of disease in tobacco pIants. In short, the production benefit of young seedIings cuItivation technique is significantIy higher than that of conventional tech-nique. [Conclusion] Referring to the young seedIings cuItivation techniques in Guizhou and Yunnan and according to the actual situation in tobacco-producing ar-eas of Panzhihua, the fIue-cured tobacco young seedIings cuItivation technique, which was suitabIe for tobacco-producing areas of Panzhihua, was deveIoped. This cuItivation technique can be used to provide tobacco seedIings for under-fiIm cuItiva-tion. In addition, it wiI provide a reference for reducing cuItivation costs, reducing environmental destruction, reducing incidence of disease and improving production efficiency of tobacco Ieaves.展开更多
Spinel exsolution is widespread in titanomagnetite from the Fe-Ti oxide gabbro of the Panzhihua intrusion, Emeishan Large Igneous Province, SW China. However, little research has been conducted into the implications o...Spinel exsolution is widespread in titanomagnetite from the Fe-Ti oxide gabbro of the Panzhihua intrusion, Emeishan Large Igneous Province, SW China. However, little research has been conducted into the implications of patterns in the mineralogical characteristics of the spinel for spatial variation in the controls on the exsolution mechanism and, hence, the formation process of the ore deposit. This study selected the Lanjiahuoshan Ore Block in the Panzhihua V-Ti magnetite deposit to explore this issue, systematically studying exsolution textures in the titanomagnetite through petrographic observation and the integrated use of in-situ microanalysis. The results show that the exsolved spinel gradually becomes finer-grained and less abundant from the center to edge and the bottom to top of the ore bodies. Compositionally, there is an inverse correlation between the size of exsolved spinel grains and their Mg# value. In addition, there is compositional zonation in the spinel interiors, with a gradual increase in the Mg content and decrease in Fe content from the core to the rim. The analysis suggests that fractional crystallization of ferrotitanium magma with a high oxygen fugacity in a shallow magma chamber caused compositional differences in the primary magnetite solid solution in different parts of the Panzhihua intrusion. Additionally, the thermal evolution of the magnetite solid solution differed in different parts of orebody, bringing about variations in spinel development. Together, these effects resulted in spatial variation in the abundance, grain size, and morphology of spinel in different parts of the orebody and intrusion that follows an identifiable distribution law. Furthermore, the compositional zonation of exsolved spinels reflects the rapid growth of exsolution features in a high-temperature environment. Thus, the size, morphology, abundance, and composition of spinel exsolution features in titanomagnetite provide a valuable petrogenetic tool for estimating the maturity and formational environment of the deposit.展开更多
Panzhihua is a resource treasure basin and natural green house of China.The demands of international market and domestically economic constructions are the important prerequisites of developing Panzhihua’s resources....Panzhihua is a resource treasure basin and natural green house of China.The demands of international market and domestically economic constructions are the important prerequisites of developing Panzhihua’s resources.Through more than 20 years construction,the city has laid a sound bases for resource utilization. In order to enlarge the functions of Panzhihua’s resources in national economy and to promote the Changjiang(Yangtze)River Industry Zone construction,China will develop Panzhihua resources actively and effectively.Through analysis,key related projects of resource development and required facilities of improving the environment of investing and specialist nursing are listed in this paper.展开更多
Mining activities have left huge uncovered slopes, large areas of gangue ground and extensive railings dams. In this paper, we studied some impacts of mining activities upon environment in Panzhihua region, southweste...Mining activities have left huge uncovered slopes, large areas of gangue ground and extensive railings dams. In this paper, we studied some impacts of mining activities upon environment in Panzhihua region, southwestern China. The environmental impacts include ecological destruction, geological disasters, environmental pollution, land damage, solid waste and occupational health effect in study area. The author suggested that local government should take some measure to reduce environmental impact in Pan...展开更多
On the basis of analyzing categories and distribution of tourism resources in Panzhihua City,spatial distribution features of the resources were explored,and spatial combination laws proposed pertinently,quantitative ...On the basis of analyzing categories and distribution of tourism resources in Panzhihua City,spatial distribution features of the resources were explored,and spatial combination laws proposed pertinently,quantitative and qualitative methods used to evaluate value of tourism resources in the city,and suggestions given for the hierarchical development of local tourism resources.展开更多
The Panzhihua layered intrusions is generated closely related to the Emeishan LIPs.This paper analyzes the spatial distribution of plagioclase and pyroxene.The quantitative texture analysis of 2209 plagioclase shows t...The Panzhihua layered intrusions is generated closely related to the Emeishan LIPs.This paper analyzes the spatial distribution of plagioclase and pyroxene.The quantitative texture analysis of 2209 plagioclase shows that the characteristic length of plagioclase is 0.54 to 0.96 mm,the intercept variation range is large,from-0.67 to 0.96,and the slope is-1.85 to-1.04,the Aspect Ratio shows from 1.84 to 2.59 and fractal dimension D is 1.908–1.933.The quantitative texture analysis of 2342 pyroxene shows that the characteristic length of pyroxene is 0.38–0.64 mm,the intercept shows from 0.46 to 2.26,The slope ranges from-2.6 to-1.47,the Aspect Ratio value varies from 1.53 to 1.71,the fractal dimension D is 0.93 to 1.13.All the CSDs results of the Panzhihua intrusions indicate that plagioclase and pyroxene form in an open magma system and undergo four replenishment of magma injection.The plagioclase crystals do not grow as the lathlike shape,and the fractal growth leads to complex crystal surface.The plagioclase undergoes deformation compaction during the crystal process,and then is oriented.The pyroxene crystals grow along an approximately triaxial ratio and undergo texture adjustment and small crystal dissolution reabsorption.When all crystals in magma system grows up to 2 mm,the pyroxene undergoes cumulation in the Panzhihua layered intrusions.The plagioclase crystallization time scale is 171.23–304.41 years,representing that the crystallization is the more uniform in central part of the melt.The nucleation density continuously increases during the crystallization process of the magma system.The time scale to reach the final maximum crystal nucleation density is 15.28–58.98 years.展开更多
The Panzhihua Ms6. 1 earthquake sequence on August 30, 2008 was relocated using the Hypo2000 ＋ HypoDD algorithm with the seismic phase data from the Sichuan and Yunnan regional digital seismic networks, and the resul...The Panzhihua Ms6. 1 earthquake sequence on August 30, 2008 was relocated using the Hypo2000 ＋ HypoDD algorithm with the seismic phase data from the Sichuan and Yunnan regional digital seismic networks, and the results show that the epicenters are distributed in the near NS direction, the length of aftershock concentration zone is about 30kin, and the main shock is about 14km in depth. The depth of the sequence is distributed in the range of 0 -4km and 5 -20km, and the layer of 4 -5kin depth is an apparent earthquake absence layer. The cross-section along the fracture＇s long axis shows there is an irregular seismic gap in the middle segment of the aftershock region, which is the rupture region of 3 the M6 3/4earthquake in 1955, and this earthquake occurred in the south of the gap. We believe that the Panzhihua Ms6. 1 earthquake sequence on August 30, 2008 was a result of rupture of the residual asperity caused by the stress adjustment of the Wenchuan Ms8. 0 earthquake. The other two profiles perpendicular to the long axis show that the focal depth in the north segment is larger and the fault plane dips NW, which is consistent with the dip of the Hongge fault.展开更多
PANZHIHUA City,situated along the border between Sichuan and Yunnan provinces, is the largest iron, steel and energy base in western China. In 1994, Panzhihua was cited as an exemplary community by the United Nations ...PANZHIHUA City,situated along the border between Sichuan and Yunnan provinces, is the largest iron, steel and energy base in western China. In 1994, Panzhihua was cited as an exemplary community by the United Nations for its contributions to the progress and development of human society So, it is hard for most people to believe that in 1965, Panzhihua was nothing more than a small, remote village that comprised only seven families.展开更多
A total of 31 topsoil samples were systematically collected from the Panzhihua mining area including steel smelting, coal mining, urban and rural districts. A normalization procedure was adopted to establish the envir...A total of 31 topsoil samples were systematically collected from the Panzhihua mining area including steel smelting, coal mining, urban and rural districts. A normalization procedure was adopted to establish the environmental geochemical baseline models for this area. By using the above baseline models, the regional geochemical baseline values of As, Cr, Cu, Ni, Pb and Zn were determined. On the basis of the baselines, the enrichment factors were used to analyze the mechanism of trace metal pollution in topsoil from anthropogenic sources, and the results showed that the serious trace metal pollution is caused by human activities in coal mine, iron mine, smelting factory, tailing dam and other industrial districts in the Panzhihua area.展开更多
基金co-supported by the China Geological Survey(Grant Nos.DD20230229,DD20190011,DD20221643)the National Key Research and Development Project of China(Grant No.2018YFC0603701)。
文摘The Panzhihua mafic intrusion,which hosts a world-class Fe-Ti-V ore deposit,is in the western Emeishan region,SW China.The formation age(~260 Ma),and Sr and Nd isotopes indicate that the Panzhihua intrusion is part of the Emeishan large igneous province and has little crustal contamination.To assess ore genesis of the Panzhihua Fe-Ti-V ore deposit,two different models have been provided to explain the formation,namely silicate immiscibility and normal fractional crystallization.Silicate immiscibility occurring around 1,000℃at the late stage of basaltic magma evolution argues against the silicate immiscibility model.Apatite-hosted melt inclusion research indicates that silicate immiscibility occurred at the late stage of Panzhihua magma evolution,which may not have offered potential to form such large ore deposits as Panzhihua.Alternatively,continuous compositional variations of the Panzhihua intrusion and calculations using thermodynamic modelling software support the hypothesis that the Panzhihua deposit was formed by normal fractional crystallization.Reciprocal trace element patterns of the Panzhihua intrusion and nearby felsic rocks also coincide with the fractional crystallization model.Normal fractional crystallization of high-Ti basaltic magma played a key role in the formation of the Panzhihua Fe-Ti-V ore deposit.
基金Projects(51090385,5114703)supported by the National Natural Science Foundation of ChinaProject(2012DFA70570)supported by the International S&T Cooperation Program of ChinaProject(2011FZ038)supported by the Applied Basic Research Project of Yunnan Province
文摘The permittivity of low grade Panzhuhua ilmenite ore at 2.45 GHz in the temperatures from 20 ℃ up to 100 ℃ was measured using the technology of open-ended coaxial sensor combined with theoretical computation. The results show that both the real （ε′） and imaginary （ε′） part of complex permittivity （ε′-jε′） of the ilmenite significantly increase with temperature. The loss tangent （tanδ） is a quadratic function of temperature, and the penetration depth of ilmenite decreases with temperature increase from 20 ℃to 100 ℃ The increase of the sample temperature under microwave radiation displays a nonlinear relationship between the temperature （T） and microwave heating time （t）. The positive feedback interaction between complex permittivity and sample temperature amplifies the interaction between ilmenite and the microwave radiation. The optimum dimensions for uniform heat deposition vary from 10 cm to 5 cm （about two power penetration depths） in a sample being irradiated from both sides in a 2.45 GHz microwave field when temperature increases from room temperature to 100 ℃
文摘Affected by southwest monsoon moisture and topography redistribution,natural precipitation in Panzhihua had obvious difference in temporal and spatial distribution.By using precipitation data from Renhe station in Panzhihua during 1965-2009,the variation characteristics of annual precipitation,flood season precipitation and seasonal precipitation were analyzed.The results showed that spring precipitation,summer precipitation,flood season precipitation and annual precipitation changed conformably and significantly since 1970s in 20th century,showing increase trend at present,while autumn precipitation showed decrease tendency.From the 10-year running mean of annual precipitation,it was found that the annual variation of precipitation resources in Panzhihua City had its own regularity,and there was a slowly decrease at present.
基金Supported by Science and Technology Fund of Panzhihua Branch of Sichuan Tobacco Company(PYS[2011]31)Science and Technology Key Project of Sichuan Branch of China National Tobacco Company(CYK[2013]4)~~
文摘[Objective] This study aimed to investigate the improving effect of quick- lime on acid soil in tobacco-growing areas in Panzhihua City. [Method] The effects of four application amounts （450, 900, 1 350 and 1 800 kg/hm2） of quicklime on soil nutrients and flue-cured tobacco quality were observed for two consecutive years. [Result] In acid soil, the application of quicklime significantly improved soil pH. In addition, it showed significant effects on soil nutrients, flue-cured tobacco quality, tobacco output and tobacco leaf chemical components. When the application amount of quicklime was increased to 1 350 kg/hm2, the improving effect of quick- lime on soil nutrients was best, the flue-cured tobacco yield and quality all reached the highest, and the chemical components of tobacco leaves were closest to the in- herent indicators of high-quality tobacco leaves. [Conclusion] This study will provide certain reference for accurate application of quicklime in tobacco-growing area in Panzhihua City.
基金The project benefited from a PROCORE Hong Kong-France exchange grant to Arndt and Zhou and a grant from the US National Science Foundation
文摘The Panzhihua intrusion in southwest China is part of the Emeishan Large Igneous Province and host of a large Fe-Ti-V ore deposit.During emplacement of the main intrusion,multiple generations of mafic dykes invaded carbonate wall rocks,producing a large contact aureole.We measured the oxygen-isotope composition of the intrusions,their constituent minerals,and samples of the country rock.Magnetite and plagioclase from Panzhihua intrusion haveδ18O values that are consistent with magmatic equilibrium, and formed from magmas withδ18O values that were 1-2‰higher than expected in a mantle-derived magma.The unmetamorphosed country rock has highδ18O values,ranging from 13.2‰（sandstone） to 24.6-28.6‰（dolomite）.The skarns and marbles from the aureole have lowerδ18O andδ13C values than their protolith suggesting interaction with fluids that were in exchange equilibrium with the adjacent mafic magmas and especially the numerous mafic dykes that intruded the aureole.This would explain the alteration ofδ18O of the dykes which have significantly higher values than expected for a mantle-derived magma.Depending on the exactδ18O values assumed for the magma and contaminant, the amount of assimilation required to produce the elevatedδ18O value of the Panzhihua intrusion was between 8 and 13.7 wt.%,assuming simple mixing.The exact mechanism of contamination is unclear but may involve a combination of assimilation of bulk country rock,mixing with a melt of the country rock and exchange with CO2-rich fluid derived from decarbonation of the marls and dolomites.These mechanisms,particularly the latter,were probably involved in the formation of the Fe-Ti-V ores.
基金The project benefited from a PROCORE Hong Kong-France Exchange Grant to N.T.Arndt and M.-F.Zhou and from a grant from the US National Science Foundation
文摘The Panzhihua gabbroic intrusion,part of the plumbing system of the Emeishan large igneous province, intruded late-Proterozoic dolomites and marls about～263 Ma ago.The dolomites in the contact aureole were converted to brucite marbles and a diverse suite of forsterite,diopside and garnet skarns.The variation in mineralogy is explained in part by differences in the composition of the protolith,particularly the proportion of silica minerals and clay,and in part by transfer of elements from intruding magmas.The trace element compositions of most marbles and skarns are very similar to those of unmetamorphosed dolomites and marls,but some contain high Si,Ti,and Fe contents that are interpreted to have come from a magmatic source.Three brucite marbles sampled～10 m from the contact of the intrusion and named ＂enriched brucite marble＂ have trace element compositions very different from their dolomitic protolith：their rare earth elements are strongly enriched whereas levels of Nb-Ta,Zr-Hf and Ti are very low.These characteristics resemble those of carbonate liquid in equilibrium with silicate liquid or more probably with silicate minerals in the case of Panzhihua,a similarity we take to indicate that the sample underwent partial melting.Samples taken up to 300 m from the contact contain brucite indicating that high temperatures persisted well into the country rocks.However,other samples collected only tens of metres from the contact are only slightly recrystallized indicating that conditions in the aureole were highly variable.We suggest that temperatures within the aureole were controlled by conduction of heat from the main intrusion and by supply of additional heat from abundant small dykes within the aureole.Circulation of fluids derived from deeper levels in the aureole flushed the carbon dioxide from the dolomite,lowering temperature needed to partially melt carbonate to the temperatures attained near the intrusion.Irregular but extensive heating destabilized the carbonates of the aureole and decarbonation reactions associated with carbonate breakdown and melting emitted a large volume of CO2,with potential impact on global climate.
基金supported by the Research Grant Council of Hong Kong(HKU707012P)to MFZa post-doctoral fellowship awarded by the National Science Council(NSC), Taiwan to KNP
文摘A sequence of gabbros showing isotropic,layered and fine-grained textures is exposed in the Nalaqing mine at the southern tip of the～260 Ma Panzhihua intrusion,SW China.The field relations,structure,texture and mineralogy of the rocks indicate that the sequence represents the transition between the Lower zone and Middle zone of the intrusion.Isotropic gabbros characteristic of the Lower zone pass upward to layered gabbros of the Middle zone through a～5 m-thick microgabbro sheet,within and close to which small-scaled, concordant Fe-Ti oxide ore horizons are identified.Strong fractionation between HFSE and REE in a subset of samples is ascribed to cumulus titanomagnetite into which HFSE are preferentially incorporated over REE,as reflected in the parallel relations between Nb/La,Hf/Sm and Ti/Ti＊.Both the isotropic and layered gabbros display cumulate textures and have similar mineral compositions（Mg# of clinopyroxene =～76-79 and An59-61）,isotopic compositions[（87Sr/86Sr）i = 0.7044-0.7045 andεNd（t） = ＋2.4 to ＋3.9]and trapped liquid contents inferred from Zr abundance（～17-34 ppm）.However,there are substantial variations in elemental abundances（V,Cr and PGE） and ratios（Ti/V,La/Yb,Ba/Y and Cu/Pd） between the two types of gabbros,features that cannot be explained by cumulate formation from a common magma in a closed system.The microgabbros generally resemble high-Ti Emeishan basalts in major element compositions,but their low trace element abundances indicate some lost of residual liquid is inevitable despite rapid nucleation and cooling.Combined with available data and observations,we propose a model involving in-situ crystallization,followed by magma recharge and closed-system fractionation to explain the formation of texturally distinctive gabbros at Nalaqing and the evolution of the lower part of the Panzhihua intrusion.
基金funding through South African National Science Foundation(NRF)Grant SA/China Project 67220 to SP and Mei-Fu ZhouGH also acknowledges the support of a doctoral fellowship from the NRF for 2011-2012
文摘Recent work on the Panzhihua intrusion has produced two separate models for the crystallisation of the intrusion：（1） low-Ti,high CaO and low H2O（0.5 wt.%） parent magma（equivalent to Emeishan low-Ti basalt） at FMQ;and（2） high-Ti,low CaO and higher H2O（＆gt;1.5 wt.%） parent magma（equivalent to Emeishan high-Ti basalt） at FMQ ＋ 1.5.Modelling of these parent magma compositions produces significantly different results. We present here detailed f（O2） and H2O modelling for average compositions of both Emeishan high-Ti and low-Ti ferrobasalts in order to constrain the effects on crystallisation sequences for Emeishan ultra-mafic -mafic layered intrusions.Modelling is consistent with numerous experimental studies on ferro-basaltic magmas from other localities（e.g.Skaergaard intrusion）.Modelling is compared with the geology of the Panzhihua intrusion in order to constrain the crystallisation of the gabbroic rocks and the Fe-Ti oxides ore layers.We suggest that the gabbroic rocks at the Panzhihua intrusion can be best explained by crystallisation from a parent magma similar to that of the high-Ti Emeishan basalt at moderate H2O contents（0.5-1 wt.%） but at the lower end of TiO2 content for typical high-Ti basalts（2.5 wt.%TiO2）. Distinct silicate disequilibrium textures in the Fe-Ti oxide ore layers suggest that an influx of H2O may be responsible for changing the crystallisation path.An increase in H2O during crystallisation of gabbroic rocks will result in the depression of silicate liquidus temperatures and resultant disequilibrium with the liquid.Continued cooling of the magma with high H2O then results in precipitation of Mt-Uv alone. The H2O content of parent magmas for mafic layered intrusions associated with the ELIP is an important variable.H2O alters the crystallisation sequence of the basaltic magmas so that at high H2O and f（O2） Mt -Uv crystallises earlier than plagioclase and clinopyroxene.Furthermore,the addition of H2O to an anhydrous magma can explain silicate disequilibrium texture observed in the Fe-Ti oxide ore layers.
基金supported by the National Science Fund for Distinguished Young Scholars of China (Grant No. 40125015)a Research Project of the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Grant No. SKLGP2010Z002)+1 种基金the Science and Technique Plans for Sichuan Province, China (Grant No. 2011SZ0182 and NO. 2013SZ0168)the Fundamental Science on Nuclear Waste and Environmental Security Laboratory (Grant No. 12zxnp04)
文摘Panzhihua city （26°O5＇-27°21＇N, 101°OS＇- 102°15＇E）, located in a mountainous area, is one of the large cities in Sichuan province, China. A landslide occurred in the filling body of the eastern part of the Panzhihua airport on October 3, 2009 （hereafter called the lo.3 landslide）. We conducted field survey on the landslide and adopted emergency monitoring and warning models based on the Internet of Things （loT） to estimate the losses from the disaster and to prevent a secondary disaster from occurring. The results showed that four major features of the airport site had contributed to the landslide, i.e, high altitude, huge amount of filling rocks, deep backfilling and great difficulty of backfilling. The deformation process of the landslide had six stages and the unstable geological structure of high fillings and an earthquake were the main causes of the landslide. We adopted relative displacement sensing technology and Global System for Mobile Communications （GSM） technology to achieve remote, real-time and unattended monitoring of ground cracks in the landslide. The monitoring system, including five extensometers with measuring ranges of 200, 450 and 7oo mm, was continuously working for 17 months and released 7 warning signals with an average warning time of about 26 hours. At 10 am on 6 December 2009, the system issued a warning and on-site workers were evacuated and equipment protected immediately. At 2：20 medium-scale collapse monitoring site, which proved the reliability pm on 7 December, a occurred at the No. 5 justified the alarm and and efficiency of the monitoring system.
基金This paper is supported by Youth Scientific Technological Fund of Sichuan Province.
文摘Mining activities have created huge uncovered slopes, large areas of gangue ground and extensive tailings dams. This paper presents the environmental geochemistry of mining activities in Panzhihua region. The selected elements (Ti, V, Mo. Ni. Pb. Cu) show similar distribution patterns of concentration anomaly in topsoil. These concentration anomalies are located in V-Ti-magnetite slope, gangues dam and coal mine. The distinction between anthropogenic contamination and natural background is made available by the use of the enrichment factor in this study area. The anomalies of EF were smaller than that of concentration. The results from EF show that the selected elements anthropogenic pollution (EF>1) in topsoil were located in both the coal mining area and the V-Ti-magnetite mining area. In addition, the pollution sources of selected elements came from V-Ti-magnetite, slag, gangues, coal and other pollutants from mining activities.
基金Project(2014CB643403)supported by the National Basic Research Program of ChinaProjects(51225401,51304132,51574164)supported by the National Natural Science Foundation of China+1 种基金Project(14JC1491400)supported by the Science and Technology Commissions of Shanghai Municipality,ChinaProject(2013GZ0146)supported by the Sichuan Province,China
文摘The hydrogen reduction of Panzhihua ilmenite concentrate in the temperature range of 900?1050 °C was systematicallyinvestigated by thermogravimetric analysis (TG), X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods. It wasshown that the products of the Panzhihua ilmenite reduced at 900 °C were metallic iron and rutile. Above 1000 °C, ferrouspseudobrookite solid solution was generated. During the reduction process, element Mg gradually concentrated to form Mg-rich zonewhich can influence the metallization process. The reduction reaction proceeded topochemically and its related reduction kineticswere also discussed. The kinetics of the reduction indicated that the rate-controlling step was the diffusion process. The apparentactivation energy of the hydrogen reduction of Panzhihua ilmenite was calculated to be 117.56 kJ/mol, which was larger than that ofsynthetic ilmenite under the same reduction condition.
文摘Objective] This study almed to expIore a suitabIe fIue-cured tobacco young seedIings cuItivation technique for tobacco-producing areas in Panzhihua. [Method] The randomized bIock design was used to conduct a two-factor test of fIoating pate and seedIing age. [Result] The young seedIings cuItivation technique re-duced the cuItivation cost by 76.6%; the optimum seedIing age was 45 d; the fIoat-ing pIate with specification of 595 hoIes/pIate couId best improve the cuItivation effi-ciency; and the Ieaf-uncut young seedIings cuItivation technique significantIy reduced the incidence of disease in tobacco pIants. In short, the production benefit of young seedIings cuItivation technique is significantIy higher than that of conventional tech-nique. [Conclusion] Referring to the young seedIings cuItivation techniques in Guizhou and Yunnan and according to the actual situation in tobacco-producing ar-eas of Panzhihua, the fIue-cured tobacco young seedIings cuItivation technique, which was suitabIe for tobacco-producing areas of Panzhihua, was deveIoped. This cuItivation technique can be used to provide tobacco seedIings for under-fiIm cuItiva-tion. In addition, it wiI provide a reference for reducing cuItivation costs, reducing environmental destruction, reducing incidence of disease and improving production efficiency of tobacco Ieaves.
基金funded by the National Natural Science Foundation of China(Grant No.41172047)the Open Fund of the Key Laboratory of Ore Deposit Geochemistry(Institute of Geochemistry,Chinese Academy of Sciences,Guiyang),(Grant No.201308)the Open Fund of the Key Laboratory Metallogeny and Mineral Resource Assessment,Ministry of Land and Resources(Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing)(Grant No.ZS1407)
文摘Spinel exsolution is widespread in titanomagnetite from the Fe-Ti oxide gabbro of the Panzhihua intrusion, Emeishan Large Igneous Province, SW China. However, little research has been conducted into the implications of patterns in the mineralogical characteristics of the spinel for spatial variation in the controls on the exsolution mechanism and, hence, the formation process of the ore deposit. This study selected the Lanjiahuoshan Ore Block in the Panzhihua V-Ti magnetite deposit to explore this issue, systematically studying exsolution textures in the titanomagnetite through petrographic observation and the integrated use of in-situ microanalysis. The results show that the exsolved spinel gradually becomes finer-grained and less abundant from the center to edge and the bottom to top of the ore bodies. Compositionally, there is an inverse correlation between the size of exsolved spinel grains and their Mg# value. In addition, there is compositional zonation in the spinel interiors, with a gradual increase in the Mg content and decrease in Fe content from the core to the rim. The analysis suggests that fractional crystallization of ferrotitanium magma with a high oxygen fugacity in a shallow magma chamber caused compositional differences in the primary magnetite solid solution in different parts of the Panzhihua intrusion. Additionally, the thermal evolution of the magnetite solid solution differed in different parts of orebody, bringing about variations in spinel development. Together, these effects resulted in spatial variation in the abundance, grain size, and morphology of spinel in different parts of the orebody and intrusion that follows an identifiable distribution law. Furthermore, the compositional zonation of exsolved spinels reflects the rapid growth of exsolution features in a high-temperature environment. Thus, the size, morphology, abundance, and composition of spinel exsolution features in titanomagnetite provide a valuable petrogenetic tool for estimating the maturity and formational environment of the deposit.
文摘Panzhihua is a resource treasure basin and natural green house of China.The demands of international market and domestically economic constructions are the important prerequisites of developing Panzhihua’s resources.Through more than 20 years construction,the city has laid a sound bases for resource utilization. In order to enlarge the functions of Panzhihua’s resources in national economy and to promote the Changjiang(Yangtze)River Industry Zone construction,China will develop Panzhihua resources actively and effectively.Through analysis,key related projects of resource development and required facilities of improving the environment of investing and specialist nursing are listed in this paper.
基金This study is granted by China Postdoctoral Science Foundation "environmental geochemical principles and techniques for assessing disturbed soil by mining activity" and China Land and Resources Ministry Special Project (No.30302408)"regional geochemical
文摘Mining activities have left huge uncovered slopes, large areas of gangue ground and extensive railings dams. In this paper, we studied some impacts of mining activities upon environment in Panzhihua region, southwestern China. The environmental impacts include ecological destruction, geological disasters, environmental pollution, land damage, solid waste and occupational health effect in study area. The author suggested that local government should take some measure to reduce environmental impact in Pan...
基金Supported by National Social Science Fund(11XMZ068)
文摘On the basis of analyzing categories and distribution of tourism resources in Panzhihua City,spatial distribution features of the resources were explored,and spatial combination laws proposed pertinently,quantitative and qualitative methods used to evaluate value of tourism resources in the city,and suggestions given for the hierarchical development of local tourism resources.
基金funded by National Basic Research Program of China(Grant No.2011CB808901)the Geological Survey Program of the China Geological Survey(Grant No.1212011220921)。
文摘The Panzhihua layered intrusions is generated closely related to the Emeishan LIPs.This paper analyzes the spatial distribution of plagioclase and pyroxene.The quantitative texture analysis of 2209 plagioclase shows that the characteristic length of plagioclase is 0.54 to 0.96 mm,the intercept variation range is large,from-0.67 to 0.96,and the slope is-1.85 to-1.04,the Aspect Ratio shows from 1.84 to 2.59 and fractal dimension D is 1.908–1.933.The quantitative texture analysis of 2342 pyroxene shows that the characteristic length of pyroxene is 0.38–0.64 mm,the intercept shows from 0.46 to 2.26,The slope ranges from-2.6 to-1.47,the Aspect Ratio value varies from 1.53 to 1.71,the fractal dimension D is 0.93 to 1.13.All the CSDs results of the Panzhihua intrusions indicate that plagioclase and pyroxene form in an open magma system and undergo four replenishment of magma injection.The plagioclase crystals do not grow as the lathlike shape,and the fractal growth leads to complex crystal surface.The plagioclase undergoes deformation compaction during the crystal process,and then is oriented.The pyroxene crystals grow along an approximately triaxial ratio and undergo texture adjustment and small crystal dissolution reabsorption.When all crystals in magma system grows up to 2 mm,the pyroxene undergoes cumulation in the Panzhihua layered intrusions.The plagioclase crystallization time scale is 171.23–304.41 years,representing that the crystallization is the more uniform in central part of the melt.The nucleation density continuously increases during the crystallization process of the magma system.The time scale to reach the final maximum crystal nucleation density is 15.28–58.98 years.
基金funded jointly by the National Natural Science Foundation of China(40674040,41074062)the scientific investigation project of the M_S 7.0 Lushan earthquakethe special program for seismic network backbones of CEA(20150422)
文摘The Panzhihua Ms6. 1 earthquake sequence on August 30, 2008 was relocated using the Hypo2000 ＋ HypoDD algorithm with the seismic phase data from the Sichuan and Yunnan regional digital seismic networks, and the results show that the epicenters are distributed in the near NS direction, the length of aftershock concentration zone is about 30kin, and the main shock is about 14km in depth. The depth of the sequence is distributed in the range of 0 -4km and 5 -20km, and the layer of 4 -5kin depth is an apparent earthquake absence layer. The cross-section along the fracture＇s long axis shows there is an irregular seismic gap in the middle segment of the aftershock region, which is the rupture region of 3 the M6 3/4earthquake in 1955, and this earthquake occurred in the south of the gap. We believe that the Panzhihua Ms6. 1 earthquake sequence on August 30, 2008 was a result of rupture of the residual asperity caused by the stress adjustment of the Wenchuan Ms8. 0 earthquake. The other two profiles perpendicular to the long axis show that the focal depth in the north segment is larger and the fault plane dips NW, which is consistent with the dip of the Hongge fault.
文摘PANZHIHUA City,situated along the border between Sichuan and Yunnan provinces, is the largest iron, steel and energy base in western China. In 1994, Panzhihua was cited as an exemplary community by the United Nations for its contributions to the progress and development of human society So, it is hard for most people to believe that in 1965, Panzhihua was nothing more than a small, remote village that comprised only seven families.
基金SupportedbytheChinaPostdoctoralScienceFoundationNationalNaturalScienceFoundationofChina (No .4 98730 2 0 )andtheYouthScientificandTechnologicalFoundationofSichuanProvince
文摘A total of 31 topsoil samples were systematically collected from the Panzhihua mining area including steel smelting, coal mining, urban and rural districts. A normalization procedure was adopted to establish the environmental geochemical baseline models for this area. By using the above baseline models, the regional geochemical baseline values of As, Cr, Cu, Ni, Pb and Zn were determined. On the basis of the baselines, the enrichment factors were used to analyze the mechanism of trace metal pollution in topsoil from anthropogenic sources, and the results showed that the serious trace metal pollution is caused by human activities in coal mine, iron mine, smelting factory, tailing dam and other industrial districts in the Panzhihua area.
