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2022yearNo.41volumeNo.5phase

  • Research on the south side landslide at west open-pit coal mine in Fushun City,Liaoning Province of China
    LIU Chuanzheng, CUI Yuan, CHEN Chunli, LYU Jietang, LI Bing, WANG Lun
    The west open-pit coal mine at Fushun in Liaoning Province of China was opened in 1901 and closed in 2018.It formed a 420 meters bottomless pit due to stepped coal mining,therefore,is called the largest pit in Asia.The south side landslide in the open-pit coal mine is a giant bedding rock landslide with 3100 meters in length from east to west and 1500 meters in width from north to south.The volume of the landslide is about 452 million cubic meters.Rainfall seepage and excavation unloading at the bottom of the mine are the main factors that lead to the landslide and the continuous long-distance movement.The concrete manifestation includes interlayer softening,groundwater buoyancy,and pore water pressure in the middle and front parts of the slope.The monitoring data from 2012 to 2019 show that the maximum horizontal displacement of the landslide is 96.01 meters,the cumulative maximum subsidence is 56.65 meters,and the full raise of the front edge is 23.61 meters.The topographic feature of the landslide area is greatly changed.The landslide movement has experienced deformation and failure before 2013,step evolution from 2013 to 2016,and gradually stabilization since 2017.The three phases reflect the rapid development of the giant landslide from the complete destruction of the bedding mountain to a gradually stable process.Analysis of the sensibility reveals the uplifting of underground water level plays an important role in decreasing slope stability,and filling soil at the toe of the slope remarkably increase slope stability.Bedding sliding resistance in the middle and upper slope,cut-layers shear resistance in the lower slope,fill pressure in leading edge,boundary resistance of bilateral,and counterforce of the north side are major factors of the gradual braking of landslide.It is manifested as the "block effect" of the boundary and the "pressure arch effect" of the leading edge.Using boundary resistance,stowage,and resistance reaction force to control the landslide process is typical.The impact and vibration effects were avoided,and the soft landing was realized.
    2022  .  41(5):    713-726    [摘要](14)    [PDF](18)
  • Mica 40Ar-39Ar isotopic chronology of Bizigou and Nanhegou copper deposit in Zhongtiao Mountain region,Shanxi Province,and its constraint on metallogenic tectonic setting
    WANG Mengqi, MAO Jingwen, YE Huishou, WANG Sai, FAN Chenglong, LI Hongying, BI Minfeng
    The Bizigou and Nanhegou copper deposits are located in the southern margin of the Trans-North China Orogen of the North China Craton.They are typical of the Hubi type copper deposits in the Zhongtiao Mountain area of Shanxi Province.Because they are controlled by strata and like stratified,they are also considered as the sediment-hosted stratiform copper deposits.However,the mineralization age of these deposits has not been determined and remain controversial.In this paper,high-precision 40Ar-39Ar dating of mica in Bizigou and Nanhegou copper deposits was carried out.The plateau age of Bizigou copper deposit sample was 1825 ±13 Ma(MSWD=8.86),and the corresponding isochron age was 1820 ±13 Ma(MSWD=5.67),inverse isochron age of 1820 ±13 Ma(MSWD =5.63).The samples from Nanhegou copper deposit obtained plateau age of 1861 ±14 Ma(MSWD=8.17),the corresponding isochron age is 1864 ±16 Ma(MSWD=8.31),and the inverse isochron age is 1865 ±16 Ma(MSWD= 8.47).The mineralization ages of the two deposits are consistent within the error range,indicating that the hydrothermal mineralization time of the Hubi type copper deposit is limited to ca.1850 Ma.This age is consistent with the peak metamorphism and retrometamorphism of ca.1.85 Ga in the Trans-North China Orogen.After that,it was found ore bearing quartz veins were developed in the mafic rocks of Zhongtiao Group.40Ar-39Ar dating of muscovite associated with sulfide in veins obtained the plateau age of 1851 ±13 Ma(MSWD= 7.47),the corresponding isochron ages of 1844 ±19 Ma(MSWD= 7.30)and inverse isochron ages of 1844 ±19 Ma(MSWD= 7.28),indicating that the mineralization is the product of the same geological event as the hydrothermal mineralization in the mining area.It is proved that metamorphic hydrothermal fluid widely acted on geological bodies throughout the region during the collision orogeny.
    2022  .  41(5):    727-739    [摘要](13)    [PDF](15)
  • Early Cambrian subduction of the Shangdan Ocean:New evidence from the Gupo high-Mg andesite in the Guanzi Town ophiolite mélanges,Gansu Province
    BI Zhiwei, WU Jixiu, ZHANG Yaguang, WANG Xiaosai, WANG Qiang, LIU Tengfei, WANG Wen
    The Gupo high-Mg andesite(HMA)is newly recognized in the Guanzi town ophiolite located in the Shangdan suture zone,Qinling Orogen.The Gupo high-Mg andestieis mainly composed of basaltic andesite,andesite,and pyroxene quartz diorite,which has relatively high contents of MgO(6.89%~8.99%),Mg#61.29~67.05),SiO2(54.27%~58.47%),and low contents of TiO2(0.27%~0.99%),K2O(0.09%~2.32%),Al2O3(12.09%~18.38%),and TFeO/MgO(0.88~1.13).The contents of REE are also low(16.59×10-6~74.5×10-6).The distribution pattern of REE is flat and slightly right type(LaN/YbN=1.03~4.93)without obvious abnormity of Eu.In addition,the rocks are enriched with large ion lithophile element such as Cs,Rb,Ba,K,and U,depleted of high field-strength element such as Nb,Ta,and Hf with low value of Ti/V.All these geochemical characteristics are identical to the typical high-Mg andesite,and are similar to the Sanukite from the Setouchi arc volcanic belt in the SW Japan.The subducted oceanic crust and the deep sediments may produce the aquiferous fluid from melted subducted oceanic crust and the deep sediments may react with the overlying mantle peridotite to form the metamorphic basalt-andesite.LA-ICP-MS U-Pb zircon date obtained from the gabbro-diorite coexisting with the Gupo metamorphic basaltic andesite indicates that the high-Mg andesitic magmatism event happened at 514±4.5 Ma.The Guanzi town high-Mg andesites was probably formed from the fore-arc tectonic environment because of the oceanic crust subducted in the Middle Cambrian.This study provides the evidence of the Shangdan oceanic subduction in the Middle Cambrian.
    2022  .  41(5):    740-753    [摘要](10)    [PDF](13)
  • Zircon U-Pb age and Hf isotopic characteristics of the Diebusige Complex in Langshan area,Inner Mongolia,and its constraints on the tectonic evolution of the Alxa Block
    NIU Pengfei, QU Junfeng, ZHANG Jin, ZHANG Beihang, ZHAO Heng
    The Alxa Block is located in the western part of the North China Craton (NCC),and its Precambrian geological evolution has been long controversial.In this study,the in-situ zircon U-Pb dating and the Lu-Hf isotope analysis were conducted on the Precambrian basement at the northeast margin of the Alxa Block,which called the Diebusige Complex.The Diebusige Complex consists mainly of metamorphic supracrustal rocks and metamorphic plutonic rocks,including high grade metamorphic gneiss,marble,quartzite,amphibolite and intruded K-felspar granite.LA-ICP-MS zircon U-Pb dating results of three paragneiss samples show that the detrital zircons from the Diebusige Complex yielded 207Pb/206Pb ages range from 2.60 Ga to 2.10 Ga,and the Diebusige Complex subjected to high grade metamorphic events at 1.98~1.90 Ga and 1.90~1.79 Ga,suggesting that the protoliths of the Diebusige Complex may be deposited at 2.10~1.98 Ga.There is no evidence of Archean rocks exposed in Langshan area,but the possibility of Archean rocks exist at deeper crustal levels cannot be ruled out.Zircon Lu-Hf isotopic data shows that the diagenetic material of the Diebusige Complex was originated from the reworking of Early-Middle Archean crust (3.42~2.79 Ga).Comparing the Diebusige Complex with the Yinshan Block and the Khondalite Belt in magmatic-metamorphic events and the Hf isotopic charateristics.We speculate that the Precambrian basements of the Alxa Block are probably part of the Khondalite Belt in Paleoproterozoic.
    2022  .  41(5):    754-773    [摘要](11)    [PDF](12)
  • Zircon U-Pb age and geochemical characteristics of the Azha intrusion in the southern Lhasa Block,Tibet and their indications for the evolutionary history of the Neo-Tethys
    OU Xinfeng, YANG Feng, KANG Zhiqiang, MU Jizhong, CUI Shiwei, NING Lidong
    A large number of magmatic rocks are exposed in the southern margin of the Lhasa Terrane,which provides great objects for studying the evolution history of the northward subduction of the Neo-Tethys along the southern margin of the Lhasa Terrane.In order to study mechanism of subduction evolution of Neo-Tethys,this paper conducts systematic petrological,geochronological and geochemical analyses of the Azha intrusions in the Shannan area of Tibet.Results show that the Azha intrusive rocks are mainly composed of quartz monzodiorite,formed during Late Cretaceous(95.0±1.4 Ma,100.2±1.4 Ma).The samples are characterized by high silicon and sodium(Na2O>K2O),belonging to high-K calc-alkaline rocks.They have high Sr(588.47×10-6,649.65×10-6),low Y(8.66×10-6,9.03×10-6)and Yb(0.87×10-6,0.92×10-6)and high Sr/Y ratio(65.17,75.02),showing the geochemical characteristics of typical adakitic rocks.Their large-ion lithophile elements such as Rb and Sr are enriched,and their high field strength elements such as Nb,Ta and Ti are depleted,along with the enrichment of LREE and the positive anomaly of Eu.The samples show low(87Sr/86Sr)i(0.703825,0.703836),high 143Nd/144Nd(0.512790,0.512798)and positive values of εNd(t)(4.08 and 4.25).Combined with previous results,it is suggested that the Azha instrusion is the product of partial melting of oceanic crust due to ridge subduction of the Neo-Tethys.
    2022  .  41(5):    774-787    [摘要](11)    [PDF](15)
  • Genesis of the Yihuang strong peraluminous S-type granite in Jiangxi Province and its constraints on Early Paleozoic intracontinental orogeny in South China
    HE Shiwei, WANG Kaixing, LIU Xiaodong, LEI Yongliang
    The Yihuang granite is located in the southeast Yihuang county of central Jiangxi Province,which belongs to the Wuyi terranes.The main lithology of the Yihuang granitoids is two-mica monzogranite.Zircon LA-ICP-MS U-Pb dating indicates that the Yihuang granitoid formed at 448 Ma.The Yihuang granitoid is characterized by high contents of SiO2,K2O,ΣREE(164.29×10-6~256.66×10-6),CaO/Na2O,A/CNK(1.23~1.45),and Rb/Sr,as well as low contents of P2O5,TiO2,TFeO/MgO,Al2O3 / TiO2,Nb,and Sr.They are enriched in LREE relatively to HREE((La/Yb)N = 12.02~34.43)with moderate Eu anomalies(δEu = 0.38 ~ 0.77).The Yihuang granite displays low εNd (t)=(-8.22 ~ -13.93)and high(87Sr / 86Sr)i=(0.71283 ~ 0.72410).Zircon 176Hf/177Hf and εHf (t)values of the Yihuang granite are 0.28155~0.28250 and -33.15 ~ 10.45,respectively,with the corresponding two-stage Nd isotopic model ages of 1.99 ~ 2.31 Ga and two-stage Hf isotopic model ages of 1.24~3.48 Ga.The characteristics mentioned above show that the Yihuang granite is similar to the strongly peraluminous S-type granitoid.The biotite in the Yihuang granite is enriched in Fe,Mg,and Ti,and the muscovite has high contents of Ti,Al,Na,and low content in Fe.Combined with zircon saturation thermometers,biotite geothermometer,muscovite geobarometer,and zircon Ce anomalies,the Yihuang granite may be formed by the partial melting of the Proterozoic felsic crust of South China under high temperature,medium pressure(9.5 kbar)and low oxygen fugacity.Under the Early Paleozoic intra-continental Orogeny,the upwelling of mantle caused by the lithospheric delamination provided heat that would have triggered the partial melting of the Proterozoic crust of South China to generate the Yihuang granite.
    2022  .  41(5):    788-809    [摘要](9)    [PDF](8)
  • Genesis of Wuduoshan I-S type granite and the constraints on the Early Paleozoic tectonic evolution of the Northern Qinling:Evidence from zircon U-Pb age,geochemistry and Sr-Nd-Hf isotopes
    HU Peng, ZENG Wei, XIONG Jinlian, LIU Xing, LI Guangyao, WANG Jiaying
    The Qinling orogenic belt,located at the junction zone of the North China plate and the Yangtze plate,has experienced a complex tectonic evolution process,and the mechanism of plate assembly and the collisional time are controversial.In this paper,the geochronology,geochemistry and Sr-Nd-Hf isotopic composition of the Wuduoshan biotite monzogranite in North Qinling studied to constrain the early Paleozoic tectonic evolution of the North Qinling.Two periods of intrusion were identified in Wudaoshan batholith,which is dating 431 Ma and 417 Ma respectively.The rocks are characterized by high silicon(SiO2 = 71.16%~74.22%),alkali and potassium rich(K2O + Na2O = 7.16%~8.88%,K2O / Na2O = 0.69~2.34)and peraluminous(A / CNK = 1.01~1.19).The total REE content is generally low,and LREE and HREE are strongly fractionated,showing a right dipping distribution pattern and slight negative Eu anomalies.They are characterized by enrichment in large ion lithophile elements(Rb,Th,U),relative depletion in high field strength elements(Nb,Ta,Zr)and Ba and Sr.They belong to "I-S" type granitoids.The Wuduoshan granite has relatively low(87Sr/ 86Sr)i values(0.70581~0.71093),and negative εNd(t)values(-6.48 to-3.18),with the corresponding two-stage Nd model age of 1.42 Ga ~1.69 Ga.Most of zircons have negative εHf(t)values(εHf(t)= -6.9~ -0.1),and tDM2 = 1.50~2.34 Ga.The isotopic characteristics indicate that the Wuduoshan granite is the product of partial melting of Paleoproterozoic-Mesoproterozoic crustal material.Combined with the tectonic evolution of Qinling orogenic belt,we concluded that the formation of Wuduoshan granite was related to the collision between Erlangping island arc and North Qinling micro-continent and belongs to syn-collisional and post-conllisional type granite,and the magma source is the ancient crustal material of North Qinling micro-continent.
    2022  .  41(5):    810-823    [摘要](8)    [PDF](16)
  • Mineralogical characteristics and constraints of formation conditions of garnet in kimberlite in Shizhuang area,southern He’nan Province
    LI Jishan, ZHANG Junjie, LIU Wei, YU Cui
    Shizhuang area in southern He nan located in the south margin of north China platform,with kimberlite.In order to determine the types of garnet and their relationship with diamond,40 selected garnet mineral single crystals were analyzed by electron probe micro-area.The results show that the cations of group A in the general formula A3B2 [SiO4]3 of the garnet mineral group are mainly occupied by Mg2+,Fe2+ and a small amount of Ca2+,the cations of group B are mainly occupied by Al3+ and a small amount of Fe3+,Cr3+ and Mn3+.The garnet in the area is mainly composed of Alm - Pry - Gro series.According to the mineral chemical characteristics,the Mg-Al garnet in the area is eclogite type,which is characterized by titanium-calcium,low-chromium and iron-rich.It belongs to Grutter’ s G4-G5 group(containing titanium and calcium)Mg-Al-Fe-Al garnet,and has the same characteristics as kimberlite,diamond inclusion or garnet in group A eclogite.Supersilicon garnet is found in the area,and its formation pressure ranges from 10.2 GPa to 10.9 GPa,with a depth of more than 250 km.
    2022  .  41(5):    824-835    [摘要](9)    [PDF](12)
  • Economic security evaluation and early warning of iron ore resources in China
    ZHENG Minggui, WU Ping, YOU Biying
    Iron ore is an important strategic mineral resource,and its economic security is related to the overall situation of national economic and social development.In order to further study the economic security of iron ore resources in China,the evaluation index system of economic security of iron ore resources in China is constructed from three aspects of resources,import market and sustainable development.The improved TOPSIS method,obstacle degree model and GM(1,1)-BP combination model are respectively used to evaluate the economic security of iron ore resources in China from 2001 to 2018,analyze the main obstacle factors and give early warning of the economic security of iron ore resources in 2020-2025.The results show that:①From 2001 to 2018,the economic security level of iron ore resources in China showed a general trend of first decreasing and then increasing,and the security warning level experienced a change from blue warning to red warning and to orange warning;②Among the first level indicators,the resource security closeness showed a fluctuating downward trend,the import market security closeness first increased and then decreased,and the sustainable development security closeness was in a fluctuating downward trend,but increased sharply after 2016;③The main obstacles affecting the economic security of iron ore resources are the reserve production ratio,the increment of proven reserves,the growth rate of exploration investment,the utilization rate of resource recovery and the relative abundance of resources;④From 2020 to 2025,the economic security closeness of iron ore resources in China will show a downward trend,and the security warning level will rise from orange warning to red warning.
    2022  .  41(5):    836-845    [摘要](8)    [PDF](10)
  • Geological characteristics and resource potential of the super-large high-quality phosphorite deposit of the Yangchang in Zhenxiong County,Yunnan Province,southwestern margin of the Upper Yangtze Block
    YUE Weihao, HUANG Yanhua, DAO Tinghong
    The Yangchang phosphorite deposit in Zhenxiong County,northeastern Yunnan Province is a newly discovered super-large high-quality phosphorite deposit with large reserves (predicted prospective resources of 13 billion tons),large ore body thickness (up to 30 meters) and excellent ore quality (low-magnesium high-calcium limestone-type phosphate rock).The phosporite deposit is located in the semi-closed shallow-water platform facies of the carbonate platform Weining-Zhaotong fold-punch belt Xiaotan-Yangchang polyphosphorite basin in front of the southwestern margin of the Upper Yangtze Continental Block,which belongs to typical Early Cambrian marine sedimentary phosphorite deposit.The study of paleostructure,lithofacies palaeogeography and phosphorite-forming conditions indicates that Suijiang-Yongshan-Zhaotong phosphorite-forming area in the west of the Xiaotan-Yangchang polyphosphorite basin have found medium-sized phosphorite deposits such as Wuji,Jinshachang and Guanfang in Yongshan County.Located in the Zhenxiong-Weixin phosphorite-forming area,east of the basin.The Yangchang phosphorite deposit has a similar metallogenic background,with good metallogenic geological conditions and great prospecting potential.Based on the comprehensive analysis of the geological background,paleostructure and lithofacies paleogeography of the Yangchang phosphorite deposit,the regional phosphorite mineralization law and prospecting direction are summarized,which provides the basis for prospecting breakthrough of the Early Cambrian marine sedimentary phosphorite deposits at the southwestern margin of the Upper Yangtze Block.
    2022  .  41(5):    846-856    [摘要](9)    [PDF](8)
  • Geological characteristics and genesis of crystalline graphite deposits in the North margin of Upper Yangtze Block
    MA Zhixin, LUO Maojin, SHI Hongliang, HUANG Teng, SUN Zhiming
    Graphite ore is a kind of important national strategic protection resource.In order to deepen the understanding of the genesis of crystalline graphite ore in the northern margin of the Upper Yangtze Block,the ore-bearing strata,ore body characteristics,ore structure and ore geochemical characteristics of many graphite deposits in the area have been studied.It was found that graphite ore was mainly distributed in the Nanjiang-Wangcang area of Sichuan,forming a graphite mineralization zone extending about 60 km from the northeast-southwest direction,and graphite ore has a tendency to increase the thickness of the ore body and the degree of crystallinity in this direction.The main and trace element proxies (SiO2,Al2O3,V/Cr,Ni/Co,etc.) reflect the formation of the ore-bearing rock series in a relatively limited,oxygen-deficient shallow carbonate platform environment.This environment is conducive to the preservation of carbon,which provide material sources for graphite ore formation.The δ13C of graphite ore is between -24.9‰ and -14.2‰,which overlaps the distribution range of δ13C of organic matter,indicating that the carbon of graphite ore comes from biological organic matter.The surrounding rock of the graphite mine contains characteristic metamorphic minerals such as sericite,biotite,garnet,andalusite,indicating that it is a set of low-green schist facies shallow metamorphic rocks.The fixed carbon content in the contact part of the magmatic rock and the graphite ore increases significantly and is accompanied by the increase of the scale structure,indicating that the thermal contact metamorphism of the rock mass promotes the further enrichment of the graphite ore.A three-stage metallogenic model of graphite deposits in the study area is initially proposed,inclunding the Mesoproterozoic primary carbonaceous sedimentation enrichment stage,Mesoproterozoic to Neoproterozoic regional metamorphic graphite nucleation stage,and Neoproterozoic rock mass thermal metamorphic crystal growth and mineralization stage.This study will provide basic materials for in-depth understanding of the formation mechanism of graphite ore in the study area and the genesis of China's crystalline graphite ore.
    2022  .  41(5):    857-872    [摘要](9)    [PDF](8)
  • Characteristics and origin of the geothermal anomaly in Sijia,Hebei Province
    XU Yiming, HAO Wenhui, FANG Shiqi, CHENG Liqun, DU Lixin, XIE Wu, NIE Chenguang
    Sijia geothermal anomaly with lot geothermal energy is located in the northwestern part of Qinglong of Hebei Province.In this paper,in order to protect and utilize the geothermal resources scientifically,the geothermal anomaly is studied by means of geothermal field measurement,hydrochemistry and isotope measurement,geophysics measurement,etc. The formation mechanism,occurrence environment and circulation mechanism of geothermal resources in four abnormal geothermal areas are discussed for the first time.According to the study of this area,it is found that the buried depth of geothermal wells in the four geothermal anomalies ranges from -0.94 m to 3.02 m,which is characterized by the shallow depth of the water level.The center of the anomaly in the area is dominated by vertical upward convective heat transfer,and the periphery of the anomaly is dominated by conductive heat transfer.The deep heat flow rises along the fault junction of the anomaly center and generates lateral migration and diffusion.It is stored within a certain range and formed geothermal anomalies in this area.The interpretation results of the CSAMT show that the deep granite body in this area is cut,so that the deep heat flow can rise along the fault,and mixed and heated to the bottom of the Sijia geothermal anomaly areas to form geothermal anomalies in the area.The results of water quality analysis indicated that the hydro-chemical type of the geothermal fluid in this area is mainly SO42--Na+ type,F- and SiO2 content both have a good positive correlation with water temperature,and those mass concentration are strictly controlled by the ground temperature field.The underground hot water in this area is replenished by atmospheric precipitation,which is the cause of the atmosphere.The value of 3H of the underground hot water in the area is low,ranging from 0.6 T.U to 0.8 T.U,which directive considers that the underground hot water in this area is older than 30 years.The achievement of these results will lead the geothermal resources exploration in eastern Hebei and similar mountainous areas.
    2022  .  41(5):    873-885    [摘要](11)    [PDF](11)
  • Sm-Nd dating of scheelite in Luojiachong W-Sn deposit,Miaoershan area,southwestern Hunan Province:Implications for polycyclic tectonic-magmatic activities and metallogenesis in South China
    DU Yun, TIAN Lei, ZHENG Zhengfu, CHEN Jianfeng, ZHANG Xiaoqiang, WANG Jingyuan, ZHOU Litong, FAN Hui, LI Chao
    The scheelite in the mining area has high Sm and Nd contents,low Sm/Nd ratio.Its Sm-Nd isochron age is 401.5±9.4 Ma (2σ,MSWD=0.90),and the initial ratio of 143Nd/144Nd is 0.5120214±0.0000098,indicating that the deposit was formed in the Late Caledonian period.Scheelite εNd (t)value is -1.91~1.99,suggesting that the ore-forming material of the deposit mainly comes from the crust.Zircon LA-ICP-MS dating of the main ore-hosting granite in the mining area shows that its petrogenetic age is 423.7±2.7 Ma (2σ,MSWD=0.61),belonging to the first intrusive episode of Late Caledonian granites.Its major element contents and characteristic parameters vary widely.Its source rocks are mainly sand clastic rocks and mudstones from the Paleo-Mesoproterozoic basement crust,and it may have assimilated and mixed some Jinningian Ca and Mg-rich magmatic rocks.Based on the results of this study and previous data,it is considered that the tectonic-magmatic activities and metallogenesis in Miaoershan area and South China are multicyclic.The dominant petrogenetic and metallogenic time of the northern and southern sections of the Miaoershan pluton are Caledonian and Indosinian respectively,showing an overall "Caledonian for north and Indosinian for south" pattern.This study aims to provide a basis for guiding the prospecting work in the area and improving the petrogenetic and metallogenic theory in South China.
    2022  .  41(5):    886-902    [摘要](8)    [PDF](9)

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