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ORIGIN OF LAOCHANG COPPER-POLYMETALLIC ORE DEPOSITS IN THE LANCANG RIFT OF THE WESTERN YUNNAN GEODEPRESSION (DIWA) REGION, CHINA
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《Geotectonica et Metallogenia》 1994年第Z2期94-95,共2页
关键词 ORE REGION DIWA ORIGIN OF LAOCHANG copper-polymetallic ORE deposits IN THE LANCANG RIFT OF THE WESTERN YUNNAN GEODEPRESSION CHINA
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Tumor deposits in axillary adipose tissue in patients with breast cancer:Do they matter? 被引量:1
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作者 Muhammed Mubarak Rahma Rashid Shaheera Shakeel 《World Journal of Clinical Cases》 SCIE 2024年第6期1045-1049,共5页
Tumor deposits(TDs)are defined as discrete,irregular clusters of tumor cells lying in the soft tissue adjacent to but separate from the primary tumor,and are usually found in the lymphatic drainage area of the primary... Tumor deposits(TDs)are defined as discrete,irregular clusters of tumor cells lying in the soft tissue adjacent to but separate from the primary tumor,and are usually found in the lymphatic drainage area of the primary tumor.By definition,no residual lymph node structure should be identified in these tumor masses.At present,TDs are mainly reported in colorectal cancer,with a few reports in gastric cancer.There are very few reports on breast cancer(BC).For TDs,current dominant theories suggest that these are the result of lymph node metastasis of the tumor with complete destruction of the lymph nodes by the tumor tissue.Even some pathologists classify a TD as two lymph node metastases for calculation.Some pathologists also believe that TDs belong to the category of disseminated metastasis.Therefore,regardless of the origin,TDs are an indicator of poor prognosis.Moreover,for BC,sentinel lymph node biopsy is generally used at present.Whether radical axillary lymph node dissection should be adopted for BC with TDs in axillary lymph nodes is still inconclusive.The present commentary of this clinical issue has certain guiding significance.It is aimed to increase the awareness of the scientific community towards this under-recognized problem in BC pathology. 展开更多
关键词 Breast cancer Tumor deposits Lymph node metastasis STAGING
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Fluid inclusion characteristics of Longmenshan copper-polymetallic deposit in Yueshan,Anhui Province,China 被引量:1
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作者 刘忠法 邵拥军 +3 位作者 疏志明 彭南海 谢友良 张宇 《Journal of Central South University》 SCIE EI CAS 2012年第9期2627-2633,共7页
The types, composition and physico-chemical conditions of primary fluid inclusions were researched. The results show that the primary fluid inclusions contain vapor and liquid phase type (Type I), daughter mineral-b... The types, composition and physico-chemical conditions of primary fluid inclusions were researched. The results show that the primary fluid inclusions contain vapor and liquid phase type (Type I), daughter mineral-bearing type (Type II) and pure liquid phase type (Type III). The compositions of vapor are mainly H20 and CO2 with a tiny amounts of CH4 and H2; the liquid phase mainly contains Mg2+, Ca2+, Na+, K+, CI- and SO]-, and w(Na+)/w(K+)〉l; the homogenization temperatures of the primary fluid inclusions can be divided into 190-250 ℃, 250-340 ℃ and 360-420 ℃, corresponding to the salinities of 4%-9%, 9%-14%, and 14%-20.43% (NaC1 equivalent mass fraction), respectively. The mineralization process can be divided into three episodes: the silicatization stage, the quartz-sulfide stage, and the carbonatization stage, and all of them are associated with the ore-forming hydrothermal fluid activity. The origin of the hydrothermal fluid is from magrnatic water mainly, and later it mixes with the groundwater and meteoric water, which lead to the decrease of temperature and salinity. The decrease of salinity, temperature and pressure are the main causes of the metallogenic elements unloading and enriching in the favorable position. 展开更多
关键词 fluid inclusions metallogenic physico-chemical condition ore-forming fluid Longmenshan copper-polymetallic deposit
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A DISCUSSION ON THE GENESIS OF THE JIAMA COPPER-POLYMETALLIC DEPOSIT, MAIZHOKUNGGER, XIZANG 被引量:1
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作者 Feng Xiaoliang, Mu Chuanlong(Chengdu Institute of Geology and Mineral Resources, Chengdu 610082, China) 《地学前缘》 EI CAS CSCD 2000年第S1期431-431,共1页
Geological setting Jiama copper\|polymetallic deposit is located at Maizhokunggar county, more than 20km away from the county town. Tectonically, it lies in the eastern sector of the Gangdise volcanic arc, occurring i... Geological setting Jiama copper\|polymetallic deposit is located at Maizhokunggar county, more than 20km away from the county town. Tectonically, it lies in the eastern sector of the Gangdise volcanic arc, occurring in the Jiama\|Rutog interarc basin. The interarc basin lies between the Poindo\|Songduo Mesozoic island chain zone in the northern side and the Jurassic\|Cretaceous south Gangdise island arc zone in the southern side. Jurassic marine carbonate and Cretaceous paralic clastic rock are exposed in the basin. Late Yanshan\|Himalaya tectonic deformation and magmatic veins are well developed. These provide good conditions for forming the copper\|polymetallic ore deposit. Jiama copper\|polymetallic deposit is the only large one explored in the Gangdise volcannic arc. 展开更多
关键词 Xizang Gangdise JIAMA SKARN deposit
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Depositional process of hyperpycnal flow deposits:A case study on Lower Cretaceous Sangyuan outcrop in the Luanping Basin,Northeast China
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作者 De-zhi Yan Ru-kai Zhu +8 位作者 Hao Shou Zhao-hui Xu Wei-hong Liu Si-cheng Zhu Zhi-cheng Lei Jing-ya Zhang Chang Liu Yi Cai Huai-min Xu 《China Geology》 CAS CSCD 2024年第3期505-516,共12页
Sedimentary process research is of great significance for understanding the distribution and characteristics of sediments.Through the detailed observation and measurement of the Sangyuan outcrop in Luanping Basin,this... Sedimentary process research is of great significance for understanding the distribution and characteristics of sediments.Through the detailed observation and measurement of the Sangyuan outcrop in Luanping Basin,this paper studies the depositional process of the hyperpycnal flow deposits,and divides their depositional process into three phases,namely,acceleration,erosion and deceleration.In the acceleration phase,hyperpycnal flow begins to enter the basin nearby,and then speeds up gradually.Deposits developed in the acceleration phase are reverse.In addition,the original deposits become unstable and are taken away by hyperpycnal flows under the eroding force.As a result,there are a lot of mixture of red mud pebbles outside the basin and gray mud pebbles within the basin.In the erosion phase,the reverse deposits are eroded and become thinner or even disappear.Therefore,no reverse grading characteristic is found in the proximal major channel that is closer to the source,but it is still preserved in the middle branch channel that is far from the source.After entering the deceleration phase,normally grading deposits appear and cover previous deposits.The final deposits in the basin are special.Some are reverse,and others are normal.They are superimposed with each other under the action of hyperpycnal flow.The analysis of the Sangyuan outcrop demonstrates the sedimentary process and distribution of hyperpycnites,and reasonably explain the sedimentary characteristics of hyperpycnites.It is helpful to the prediction of oil and gas exploration targets in gravity flow deposits. 展开更多
关键词 Hyperpycnal flow Sedimentary characteristics depositional process Gravity flow deposit Hyperpycnite Red mud pebble Gray mud pebble Oil and gas exploration engineering Luanping Basin
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Mineralogical study and significance of the basalt-hosted Carlin-type Au deposits in southwestern Guizhou Province,China
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作者 Yuhong Yang Shen Liu +3 位作者 Jianzhong Liu Zepeng Wang Bingqiang Zhang Chengfu Yang 《Acta Geochimica》 EI CAS CSCD 2024年第6期1241-1254,共14页
The Jiadi and Damaidi gold deposits in southwest Guizhou Province are the largest basalt-hosted Carlintype gold deposits recently discovered in China.This study uses the Tescan Integrated Mineral Analyzer,supported by... The Jiadi and Damaidi gold deposits in southwest Guizhou Province are the largest basalt-hosted Carlintype gold deposits recently discovered in China.This study uses the Tescan Integrated Mineral Analyzer,supported by detailed field investigations,regional geological data,and extensive sample collections,including mineralized ore,altered wall rock,and unaltered basalt samples,for orebearing and geochemical analyses.Comparative analysis between altered and unaltered basalt samples revealed a mineral assemblage of sericite,quartz,and pyrite.This mineral composition forms through the hydrothermal alteration of unaltered basalt,originally containing feldspar,pyroxene,and ilmenite.The wall rock primarily features sericite,quartz,and hematite.During the alteration process,major,trace,and rare earth elements notably migrate.In the Jiadi deposit,K_(2)O,Rb,Au,and REE significantly increase,while Na_(2)O,CaO,MgO,and MnO decrease.SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3)levels remain relatively stable.In the Damaidi deposit,K_(2)O,Rb,and Au enrich,contrasting with the depletion of Na_(2)O,CaO,MgO,and MnO,while SiO_(2),Fe_(2)O_(3),Al_(2)O_(3),TiO_(2),and REE show no significant changes.In the wall rock,TiO_(2),Al_(2)O_(3),K_(2)O,and REE increase,while Na_(2)O,CaO,MgO,and MnO decrease;SiO_(2)and Fe_(2)O_(3)content remains unchanged.The mineralization process likely originated from mid-to low-temperature,reductive magmatic hydrothermal fluids rich in CO_(2),CH_(4),N_(2),H^(+),S^(2-),HS^(-),H_(3)AsO_(3),and[Au(HS_(2)]^(-).These fluids migrated to tectonically weak zones in the Lianhuashan area,where Emeishan basalts are present.They reacted with Fe-bearing minerals in the basalt,such as ferro-hornblende and ilmenite,forming pyrite,arsenic-bearing pyrite,and arsenopyrite,thus enriching Au in these minerals.Additionally,K^(+)and H^(+)in the fluid reacted with plagioclase in the basalt,forming sericite and quartz.As the fluid entered the wall rock from structural weak zones,its oxidation increased,leading to the complete or partial reaction of Fe-bearing minerals in the wall rock,resulting in the formation of hematite or magnetite.This mineralization process is similar to that observed in carbonate-hosted Carlin-type gold deposits in southwest Guizhou,with the primary distinction being the iron source.In carbonate deposits,iron originates from ferridolomite within the wall rock,while in basalt-hosted deposits,it derives from ferripyroxene and ilmenite. 展开更多
关键词 BASALTIC Ore-bearing rocks CARLIN-TYPE Au deposit Mineralogy Mineral assemblage Element migration
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Effects of soil crust on the collapsing erosion of colluvial deposits with granite residual soil
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作者 LIU Weiping ZENG Bohan +1 位作者 WANG Tianhuan DUAN Junyi 《Journal of Mountain Science》 SCIE CSCD 2024年第8期2579-2591,共13页
Collapsing erosion is a unique phenomenon commonly observed on the granite residue hillslopes in the tropical and subtropical regions of southern China,characterized by its abrupt occurrence and significant erosion vo... Collapsing erosion is a unique phenomenon commonly observed on the granite residue hillslopes in the tropical and subtropical regions of southern China,characterized by its abrupt occurrence and significant erosion volumes.However,the impacts of soil crust conditions on the erosion of colluvial deposits with granite residual soils have only been studied to a limited extent.To address this issue,this study investigates the impacts of three soil crust conditions(i.e.,without crust,10-minute crust,and 20-minute crust)on gully morphology,rainfall infiltration,and runoff and sediment yield during slope erosion of colluvial deposits with granite residues(classified as Acrisols)in Yudu County,Ganzhou City,Jiangxi Province,China,using simulated rainfall tests and photographic methods.The results showed that as the strength of the soil crust increased,the capacity of moisture infiltration and the width and depth of the gully as well as the sediment concentration and yield ratio decreased;at the same time,the runoff ratio increased.The sediment yield in the without-crust test was found to be 1.24 and 1.43 times higher than that observed in the 10-minute crust and 20-minute crust tests,respectively.These results indicate that soil crusts can effectively prevent slope erosion and moisture infiltration,while providing valuable insights for the management of soil erosion in natural environments. 展开更多
关键词 Granite residual soil Colluvial deposits Slope erosion Soil crust Sediment yield
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A Novel Three-stage Tectonic Model for Mississippi Valleytype Zn-Pb Deposits in Orogenic Fold-and-Thrust Belts
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作者 SONG Yucai 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第4期843-849,共7页
Mississippi Valley-type(MVT) Zn-Pb deposits predominantly form within both orogenic forelands and fold-andthrust belts, yet the mineralization process within the latter tectonic setting remains inadequately understood... Mississippi Valley-type(MVT) Zn-Pb deposits predominantly form within both orogenic forelands and fold-andthrust belts, yet the mineralization process within the latter tectonic setting remains inadequately understood. This study, through a comprehensive review of MVT deposits across global fold-and-thrust belts, introduces a novel model elucidating the mineralization process in the context of tectonic belt evolution. It is demonstrated that during the stage Ⅰ, regional compression is introduced by early stages of plate convergence, causing the folding and thrusting and creating structural or lithological traps such as evaporite diapirs and unconformity-related carbonate dissolution-collapse structures. Thereafter, in stage Ⅱ, hydrocarbons begin to migrate and accumulate within these traps, where reduced sulfur is generated through thermochemical or bacterial sulfate reduction concurrent with or preceding Zn-Pb mineralization. In the subsequent stage Ⅲ, as plate convergence persists, the regional stress transitions from compression to transpression or extension. Under these conditions, steeply-dipping extensional faults are generated, facilitating the ascent of metalliferous brines into early-formed structural or lithological traps. Precipitation of Zn and Pb sulfides occurs through the mixing of Zn-Pb-transporting fluids with pre-existing reduced sulfur or by interaction with hydrocarbons. 展开更多
关键词 Mississippi Valley-type Zn-Pb deposits fold-and-thrust belts tectonic model structural or lithological traps extensional faults
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Research on the Application of Electromagnetic Method in the Exploration of Altered Rock-type Gold Deposits in the East Kunlun Metallogenic Belt
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作者 DONG Ji’en ZHANG Huiqing +4 位作者 WANG Peng LI Hua YE Gaofeng YU Xiaoliang LI Jie 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第S01期18-21,共4页
Introduction The East Kunlun Orogenic Belt is located in the northeastern part of the Qinghai–Tibet Plateau(Li et al.,2007),stretching from the East Kunlun to the Elashan area in an east–west direction(Guo et al.,20... Introduction The East Kunlun Orogenic Belt is located in the northeastern part of the Qinghai–Tibet Plateau(Li et al.,2007),stretching from the East Kunlun to the Elashan area in an east–west direction(Guo et al.,2018).It is an important part of the Central Orogenic Belt(Xiong et al.,2023).It is considered one of the important gold mineralization regions in the Tethys tectonic domain(Norbu et al.,2023)and an essential potential base for mineral resources in China.Wulonggou and Gouli gold mines have been discovered successively,earning the reputation of the"Golden Belt of Qinghai Province"(Feng et al.,2004;He et al.,2023). 展开更多
关键词 electromagnetic method altered rock-type gold deposits Mailong mining area East Kunlun metallogenic belt
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Storm Liquefaction Deposits:A Possibility of Time Reversal in Sedimentary Strata of an Estuarial Coastal Area
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作者 XU Guohui REN Yupeng +3 位作者 HU Guanghai LIU Zhiqin SUN Yongfu LIN Lin 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第4期961-969,共9页
In the sedimentary strata dating of estuarial coastal areas,it is often found that there is phenomenon of time-reversal in strata.The seabed sediments could be liquefied under storm waves.A laboratory wave flume exper... In the sedimentary strata dating of estuarial coastal areas,it is often found that there is phenomenon of time-reversal in strata.The seabed sediments could be liquefied under storm waves.A laboratory wave flume experiment demonstrated that storm-induced liquefaction deposits are formed by the oscillations of liquefied sediments.In this paper,the particle size distribution and ^(210)Pb_(ex) specific activity of the sediment samples from the liquefaction disturbed zone and adjacent stable zone of the Yellow River Delta were tested.The stratigraphic divisions based on storm liquefaction deposit sequence can effectively explain the vertical changes in particle size and ^(210)Pb_(ex) specific activity.Due to the differentiation of particles during the storm induced liquefaction,coarse and fine particles regrouped,which could explain the phenomenon of time-reversal in dating data. 展开更多
关键词 ^(210)Pb_(ex)specific activity liquefaction deposition REVERSAL sediment
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Impact of Pollutant Concentration and Particle Deposition on the Radiative Flow of Casson-Micropolar Fluid between Parallel Plates
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作者 Ghaliah Alhamzi Badr Saad T.Alkahtani +2 位作者 Ravi Shanker Dubey Vinutha Kalleshachar Neelima Nizampatnam 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期665-690,共26页
Assessing the behaviour and concentration of waste pollutants deposited between two parallel plates is essential for effective environmental management.Determining the effectiveness of treatment methods in reducing po... Assessing the behaviour and concentration of waste pollutants deposited between two parallel plates is essential for effective environmental management.Determining the effectiveness of treatment methods in reducing pollution scales is made easier by analysing waste discharge concentrations.The waste discharge concentration analysis is useful for assessing how effectively wastewater treatment techniques reduce pollution levels.This study aims to explore the Casson micropolar fluid flow through two parallel plates with the influence of pollutant concentration and thermophoretic particle deposition.To explore the mass and heat transport features,thermophoretic particle deposition and thermal radiation are considered.The governing equations are transformed into ordinary differential equations with the help of suitable similarity transformations.The Runge-Kutta-Fehlberg’s fourthfifth order technique and shooting procedure are used to solve the reduced set of equations and boundary conditions.The integration of a neural network model based on the Levenberg-Marquardt algorithm serves to improve the accuracy of predictions and optimize the analysis of parameters.Graphical outcomes are displayed to analyze the characteristics of the relevant dimensionless parameters in the current problem.Results reveal that concentration upsurges as the micropolar parameter increases.The concentration reduces with an upsurge in the thermophoretic parameter.An upsurge in the external pollutant source variation and the local pollutant external source parameters enhances mass transport.The surface drag force declines for improved values of porosity and micropolar parameters. 展开更多
关键词 Micropolar fluid thermal radiation porous medium thermophoretic particle deposition waste discharge concentration
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Association between intra-pancreatic fat deposition and diseases of the exocrine pancreas: A narrative review
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作者 Jing Ye Jian-Guo Wang +2 位作者 Rong-Qiang Liu Qiao Shi Wei-Xing Wang 《World Journal of Gastroenterology》 SCIE CAS 2025年第2期27-41,共15页
Intrapancreatic fat deposition(IPFD)has garnered increasing attention in recent years.The prevalence of IPFD is relatively high and associated with factors such as obesity,age,and sex.However,the pathophysiological me... Intrapancreatic fat deposition(IPFD)has garnered increasing attention in recent years.The prevalence of IPFD is relatively high and associated with factors such as obesity,age,and sex.However,the pathophysiological mechanisms underlying IPFD remain unclear,with several potential contributing factors,including oxida-tive stress,alterations in the gut microbiota,and hormonal imbalances.IPFD was found to be highly correlated with the occurrence and prognosis of exocrine pan-creatic diseases.Although imaging techniques remain the primary diagnostic approach for IPFD,an expanding array of biomarkers and clinical scoring systems have been identified for screening purposes.Currently,effective treatments for IPFD are not available;however,existing medications,such as glucagon-like peptide-1 receptor agonists,and new therapeutic approaches explored in animal models have shown considerable potential for managing this disease.This paper reviews the pathogenesis of IPFD,its association with exocrine pancreatic disea-ses,and recent advancements in its diagnosis and treatment,emphasizing the significant clinical relevance of IPFD. 展开更多
关键词 Intrapancreatic fat deposition Pancreatic steatosis Nonalcoholic fatty pancreas disease PANCREATITIS Pancreatic cancer
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Estimation of lead and zinc emissions from mineral exploitation based on characteristics of lead/zinc deposits in China 被引量:15
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作者 张秀武 杨林生 +3 位作者 李永华 李海蓉 王五一 葛全胜 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第11期2513-2519,共7页
Nonferrous mining activities are some of the largest sources of heavy metals emissions into the environment and China is one of the largest producers and consumers of lead and zinc in the world.The cumulative producti... Nonferrous mining activities are some of the largest sources of heavy metals emissions into the environment and China is one of the largest producers and consumers of lead and zinc in the world.The cumulative productions and emissions of lead and zinc from mining-related activities in China were estimated.Up to 2007,the cumulative productions of lead and zinc in China were estimated to be about 6.69 and 12.59 Mt,respectively;and about 1.62 Mt lead and 3.32 Mt zinc emitted into the ambient environment during the mining,processing and smelting activities,representing 24.39% and 26.36% cumulative production,respectively.Among these three types of mining-related activities,mineral processing contributes the most to the total emission of 50.67% lead and 45.51% zinc. 展开更多
关键词 lead/zinc deposit LEAD ZINC cumulative production emission flux
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Three-dimensional orebody modelling and intellectualized longwall mining for stratiform bauxite deposits 被引量:4
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作者 王少锋 李夕兵 +4 位作者 王善勇 李启月 陈冲 冯帆 陈英 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第10期2724-2730,共7页
Acoupled biharmonic spline and linear interpolation algorithm was proposed to create a three-dimensional smooth deposit model with minimal curvature containing grade and position data. To obtain the optimal technical ... Acoupled biharmonic spline and linear interpolation algorithm was proposed to create a three-dimensional smooth deposit model with minimal curvature containing grade and position data. To obtain the optimal technical parameters, such as cuttingheight and drum diameter, a virtual longwall mining procedure was modelled by simulating the actual fully mechanized longwall mining process. Based on the above work, a bauxite deposit in a longwall mining panel was modelled by scattered grade data from ores sampled on the entry wall. The deposit was then demarcated by industrial indexes and sliced according to the virtual longwallmining procedure. The results show that the proposed interpolation algorithm can depict the stratiform structure of bauxite depositsand that the uncovered bauxite deposit has high proportions of high-grade and rich ore. The ranges of optimal cutting height and drum diameters are 1.72-2.84 m and 1.42-1.72 m, respectively. Finally, an intellectualized longwall mining procedure was designed to guide the mining process with the lowest dilution and loss rates. 展开更多
关键词 stratiform bauxite deposit orebodymodelling interpolation algorithm virtual longwall mining cutting height drum diameter
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Geotectonic Settings of Large and Superlarge Mineral Deposits on the Southwestern Margin of the North China Plate 被引量:7
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作者 汤中立 白云来 李志林 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2002年第3期367-377,共11页
The geotectonic setting refers to the three-dimensional space and relatedevents based on which a metallogenic system is formed and an ore-forming process takes place. Thispaper discusses the tectonic evolution of the ... The geotectonic setting refers to the three-dimensional space and relatedevents based on which a metallogenic system is formed and an ore-forming process takes place. Thispaper discusses the tectonic evolution of the southwestern margin of the North China paleocontinentand related geotectonic settings in which large or superlarge deposits are formed. Emphasis is puton the geodynamic conditions of the Jinchuan nickel-copper deposit, the Baiyin copper-polymetallicdeposit and the Hanshan gold deposit. It is significant that the three deposits occur together as a'trinity' on the same paleocontinental margin. The Jinchuan nickel-copper deposit was formed duringthe early stage of rifting of the paleocontinental margin; the Baiyin copper-polymetallic depositwas formed during the splitting stage of a continental-margin arc. The continental-margin arcspitting resulted in an 'island arc rift' in the early stage of evolution. The Hanshan gold depositwas formed within the Altun sinistral strike-slip fault system and its provenance is the'intraoceanic arc' volcanic rocks. 展开更多
关键词 North China plate tectonic evolution Jinchuan nickel-copper deposit Baiyin copper-polymetallic deposit Hanshan gold deposit
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The conjunction of factors that lead to formation of giant gold provinces and deposits in non-arc settings 被引量:13
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作者 David I.Groves Richard J.Goldfarb M.Santosh 《Geoscience Frontiers》 SCIE CAS CSCD 2016年第3期303-314,共12页
It is quite evident that it is not anomalous metal transport,nor unique depositional conditions,nor any single factor at the deposit scale,that dictates whether a mineral deposit becomes a giant or not.A hierarchical ... It is quite evident that it is not anomalous metal transport,nor unique depositional conditions,nor any single factor at the deposit scale,that dictates whether a mineral deposit becomes a giant or not.A hierarchical approach thus is required to progressively examine controlling parameters at successively decreasing scales in the total mineral system to understand the location of giant gold deposits in non-arc environments.For giant orogenic,intrusion-related gold systems(IRGS) and Carlin-type gold deposits and iron oxide-copper-gold(IOCG) deposits,there are common factors among all of these at the lithospheric to crustal scale.All are sited in giant gold provinces controlled by complex fundamental fault or shear zones that follow craton margins or,in the case of most Phanerozoic orogenic giants,define the primary suture zones between tectonic terranes.Giant provinces of IRGS,IOCG,and Carlin-type deposits require melting of metasomatized lithosphere beneath craton margins with ascent of hybrid lamprophyric to granitic magmas and associated heat flux to generate the giant province.The IRGS and IOCG deposits require direct exsolution of volatile-rich magmatic-hydrothermal fluids,whereas the association of such melts with Carlin-type ores is more indirect and enigmatic.Giant orogenic gold provinces show no direct relationship to such magmatism.forming from metamorphic fluids,but show an indirect relationship to lamprophyres that reflect the mantle connectivity of controlling first-order structures.In contrast to their province scale similarities,the different giant gold deposit styles show contrasting critical controls at the district to deposit scale.For orogenic gold deposits,the giants appear to have formed by conjunction of a greater number of parameters to those that control smaller deposits,with resultant geometrical and lithostratigraphic complexity as a guide to their location.There are few giant IRGS due to their inferior fluid-flux systems relative to orogenic gold deposits,and those few giants are essentially preservational exceptions.Many Carlin-type deposits are giants due to the exceptional conjunction of both structural and lithological parameters that caused reactive and permeable rocks,enriched in syngenetic gold,to be located below an impermeable cap along antiformal "trends".Hydrocarbons probably played an important role in concentrating metal.The supergiant Post-Betze deposit has additional ore zones in strain heterogeneities surrounding the pre-gold Goldstrike stock.All unequivocal IOCG deposits are giant or near-giant deposits in terms of gold-equivalent resources,partly due to economic factors for this relatively poorly understood,low Cu-Au grade deposit type.The supergiant Olympic Dam deposit,the most shallowly formed deposit among the larger IOCGs,probably owes its origin to eruption of volatile-rich hybrid magma at surface,with formation of a large maar and intense and widespread brecciation,alteration and Cu-Au-U deposition in a huge rock volume. 展开更多
关键词 Giant gold deposits Orogenic gold Carlin deposits Iron oxide-copper-gold deposits Intrusion-related gold systems LITHOSPHERE
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In, Sn, Pb and Zn Contents and Their Relationships in Ore-forming Fluids from Some In-rich and In-poor Deposits in China 被引量:16
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作者 ZHANG Qian ZHU Xiaoqing +1 位作者 HE Yuliang ZHU Zhaohui 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2007年第3期450-462,共13页
All the indium-rich deposits with indium contents in ores more than 100×10^-6 seems to be of cassiterite-sulfide deposits or Sn-bearing Pb-Zn deposits, e.g., in the Dachang Sn deposit in Guangxi, the Dulong Sn-Zn... All the indium-rich deposits with indium contents in ores more than 100×10^-6 seems to be of cassiterite-sulfide deposits or Sn-bearing Pb-Zn deposits, e.g., in the Dachang Sn deposit in Guangxi, the Dulong Sn-Zn deposit in Yunnan, and the Meng'entaolegai Ag-Pb-Zn deposit in Inner Mongolia, the indium contents in ores range from 98×10^-6 to 236×10^-6 and show a good positive correlation with contents of zinc and tin, and their correlation coefficients are 0.8781 and 0.7430, respectively. The indium contents from such Sn-poor deposits as the Fozichong Pb-Zn deposit in Guangxi and the Huanren Pb-Zn deposit in Liaoning are generally lower than 10×10^-6, i.e., whether tin is present or not in a deposit implies the enrichment extent of indium in ores. Whether the In enrichment itself in the ore -forming fluids or the ore-forming conditions has actually caused the enrichment/depletion of indium in the deposits? After studying the fluid inclusions in quartz crystallized at the main stage of mineralization of several In-rich and In-poor deposits in China, this paper analyzed the contents and studied the variation trend of In, Sn, Pb and Zn in the ore-forming fluids. The results show that the contents of lead and zinc in the ore-forming fluids of In-rich and -poor deposits are at the same level, and the lead contents range from 22×10^-6 to 81×10^-6 and zinc from 164×10^-6 to 309×10^-6, while the contents of indium and tin in the ore-forming fluids of In-rich deposits are far higher than those of Inpoor deposits, with a difference of 1-2 orders of magnitude. Indium and tin contents in ore-forming fluid of In-rich deposits are 1.9×10^-6-4.1×10^-6 and 7×10^-6-55×10^-6, and there is a very good positive correlation between the two elements, with a correlation coefficient of 0.9552. Indium and tin contents in ore-forming fluid of In-poor deposits are 0.03×10^-6-0.09×10^-6 and 0.4×10^-6-2.0×10^-6, respectively, and there is no apparent correlation between them. This indicates, on one hand, that In-rich oreforming fluids are the material basis for the formation of In-rich deposits, and, on the other hand, tin probably played a very important role in the transport and enrichment of indium. 展开更多
关键词 In-rich deposit In-poor deposit ore-forming fluid fluid inclusion ore-forming elements
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M agmatic Gold Mineralization in the Western Qinling Orogenic Belt: Geology and Metallogenesis of the Baguamiao,Liba and Xiaogouli Gold Deposits 被引量:12
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作者 FENGJianzhong WANGDongbo +2 位作者 WANGXueming ZENGYishan LITiefeng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第2期529-533,共5页
The superlarge Baguamiao, large Liba and Xiaogouli gold deposits represent three typical gold deposits different from the Carlin type in the western Qinling Orogenic Belt. Based on Ar-Ar dating of quartz from ores, U-... The superlarge Baguamiao, large Liba and Xiaogouli gold deposits represent three typical gold deposits different from the Carlin type in the western Qinling Orogenic Belt. Based on Ar-Ar dating of quartz from ores, U-Pb dating of single zircon from granite, tracing of H and O isotopes and studies on the mineralogy and texture of spots and bleached alteration developed in wall rocks, this paper focuses the relations between gold deposits and granite to clarify the origin of gold deposits and the metallogenesis in the tectonic evolution of the Qinling Orogenic Belt. The comprehensive studies show that the age of the granite (148.1-244 Ma) is identical with that of the gold deposits (131.91-232.56 Ma). It is suggested that the granite has close temporal, spatial and genetic relationship with the gold deposits. The granite provides a heat source, water source and considerable amount of ore-forming material. Finally, it is concluded that the orogeny by collision, emplacement of the granite and positioning of the gold deposits represent a successive process. Both the granite and gold deposits resulted from the syn-orogeny and post-orogeny tectonic evolution. 展开更多
关键词 Western Qinling Orogenic Belt Baguamiao Gold deposit Liba Gold deposit Xiaogouli Gold deposit GRANITE
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Giant Mineral Deposits and Their Geodynamic Setting in the Lanping Basin, Yunnan, China 被引量:22
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作者 XUEChunji LIUShuwen +2 位作者 CHENYuchuan ZENGRong ZHAOShihua 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第2期368-374,共7页
There are giant mineral deposits, including the Jinding Zn-Pb and Baiyangping Ag-Co-Cu, and otherimportant mineral deposits (e.g., Baiyangchang Ag-Cu, Jinman Cu deposits, etc.) in the Lanping Mesozoic-Cenozoic Basin, ... There are giant mineral deposits, including the Jinding Zn-Pb and Baiyangping Ag-Co-Cu, and otherimportant mineral deposits (e.g., Baiyangchang Ag-Cu, Jinman Cu deposits, etc.) in the Lanping Mesozoic-Cenozoic Basin, Yunnan Province, China. The tabular ore-bodies and some veins hosted in terrestrial clastic rocks of the Mesozoic-Cenozoic age and no outcropping of igneous rocks in the giant deposits lead to the proposal of syngenetic origin, but the giant mineral deposits are not stratabound (e.g. MVT, sandstone- and Sedex-type). They formed in a continental red basin with intense crust movement. The mineralization is controlled by structures and lithology and occurs in different strata, and no sedimentary nature and no exhalative sediments are identified in the deposits. The deposits show some relations with organic matter (now asphalt and petroleum) and evaporates (gypsum). The middle-low-temperature (mainly 110℃ to 280℃) mineralization took place at a depth of about 0.9 km to 3.1 km during the early Himalayan (58 to 67 Ma). The salinity of ore-forming fluids is surprisingly low (1.6% to 18.0 wt% (NaCl)eq). Affected by the collision of the Indian and Eurasian plates, the mantle is disturbed under the Lanping Basin. The large-scale mineralization is closely linked with the geodynamics of the crust movement, the mantle and mantle-flux upwelling and igneous activity. Giant mineral deposits and their geodynamic setting are unique in the Lanping Basin. 展开更多
关键词 giant Jinding Zn-Pb deposit giant Baiyangping Ag-Co-Cu deposit ore geology geodynamic setting Lanping Basin Yunnan Province China
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Laumontitization as an Exploration Indicator of Epithermal Gold Deposits: A Case Study of the Axi and Other Epithermal Systems in West Tianshan, China 被引量:8
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作者 陈衍 鲍景新 +2 位作者 张增杰 陈华勇 刘玉琳 《Chinese Journal Of Geochemistry》 EI CAS 2003年第4期289-301,共13页
In the light of field investigation, microscopic study, X\|ray phase analysis and mineral infrared spectral analysis, it is considered that laumontitization is of extensive occurrence in the Axi gold orefield. The dev... In the light of field investigation, microscopic study, X\|ray phase analysis and mineral infrared spectral analysis, it is considered that laumontitization is of extensive occurrence in the Axi gold orefield. The development of laumontitization and its relationship to mineralization show that the laumontitization appeared mainly at the top of and in the periphery of orebodies, and occurred at the edge of the epithermal system or at the late stage of epithermal system evolution. Therefore, laumontitization can be used as an exploration indicator of epithermal gold deposits. The fluids responsible for laumontitization in the Axi gold orefield are similar to those producing hot spring\|type gold deposits or those from modern geothermal fields. Epithermal mineralization of the Axi gold deposit was dated at Carboniferous, indicating that the West Tianshan of China is a region favorable to epithermal\|type gold mineralization and preservation. Hence the West Tianshan of China is a target area for exploring epithermal gold deposits. 展开更多
关键词 AXI GOLD deposit laumonfitizafion EPITHERMAL GOLD deposit geothermal metaliogenic system WEST TIANSHAN
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