检索结果-南通市图书馆

Zircon U-Pb-Hf isotopes and mineral chemistry of Early Cretaceous granodiorite in the Lunggar iron deposit in central Lhasa, Tibet Y, China

引用

Journal of Central South University 2019年第12期26卷 3457-3469页

作者： ZHANG Yun-hui WANG Yang-shuang WANG Wen-shu LIU Jie YUAN Ling-ling key laboratory of metallogenic prediction of nonferrous metals and geological environment monitoring Ministry of EducationSchool of Geoscience and Info-physicsCentral South UniversityChangsha 410083China Faculty of Geosciences and environmental Engineering Southwest Jiaotong UniversityChengdu 611756China State key laboratory of Geohazard Prevention and Geoenvironment Protection College of Environment and Civil EngineeringChengdu University of TechnologyChengdu 610059China

The Lunggar iron deposit belongs to the Bangong-Nujiang metallogenic belt and is located in central Lhasa on the Tibetan *** the Lunggar deposit,iron mineralization formed in the skarnization contact zone between the Early Cretaceous granodiorite and the late Permian Xiala Formation *** this study,we achieved detailed zircon U-Pb-Hf isotopes and mineral chemistry for the Early Cretaceous *** U-Pb dating results indicate that the Early Cretaceous granodiorite emplaced at ca.119 *** on the trace elements in zircons and the mineral chemical composition of amphibole and biotite,the Early Cretaceous granodiorite was believed to form under condition of high temperature(>700°C),low pressure(100400 MPa),and relatively high oxygen fugacity(lgfO2)(13.6 to 13.9)and H2O content(4%8%).Zircon trace elements,Hf isotope and biotite chemistry collectively reveal that significant juvenile mantle-derived magmas contributed to the source of the *** relatively high logfO2 and shallow magma chamber are beneficial for skarn iron mineralization,implying remarkable potential for further prospecting in the Lunggar iron deposit.

关键词： zircon U-Pb-Hf isotope mineral chemistry crystallization condition Lunggar iron deposit central Lhasa

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of high temperature on the microstructure and mechanical behavior of hard coal

引用

International Journal of Mining Science and Technology 2020年第5期30卷 643-650页

作者： Chengdong Su Jiadong Qiu Qiuhong Wu Lei Weng School of Energy Science and Engineering Collaborative Innovation Center of Coal Work SafetyHenan Polytechnic UniversityJiaozuo 454003China key laboratory of metallogenic prediction of nonferrous metals and geological environment monitoring(Central South University) Ministry of EducationChangsha 410083China Work Safety key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines Hunan Provincial Key Laboratory of Safe MiningXiangtan 411201China School of Civil Engineering Wuhan UniversityWuhan 430072China

Coal is a common porous sedimentary rock whose microstructure and mechanical behavior are often affected by high *** order to deeply investigate the effect of high temperature on the structure and mechanical properties of coal,six groups of coal samples with different heating temperatures were *** testing methods,including ultrasonic test,scanning electron microscopy,nuclear magnetic resonance and uniaxial compression test,were used in this *** results showed that the physical and chemical change processes of coal samples under high temperature can be divided into two stages:the stage of drying and degassing and the stage of pyrolysis of the coal *** the increase of heating temperature,the total porosity of coal samples increases,while the integrity and the deformation resistance of coal samples *** addition,the elastic modulus and uniaxial compressive strength of the coal sample decrease with the increase of heating *** Poisson’s ratio decreases firstly and then increases with the increase of heating temperature.

关键词： High temperature Coal Microstructure Mechanical behavior Nuclear magnetic resonance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Numerical investigation on the tensile fracturing behavior of rock-shotcrete interface based on discrete element method

引用

International Journal of Mining Science and Technology 2020年第3期30卷 293-301页

作者： Jiadong Qiu Lin Luo Xibing Li Diyuan Li Ying Chen Yong Luo Shenzhen key laboratory of Deep Underground Engineering Sciences and Green Energy Shenzhen UniversityShenzhen 518060China key laboratory of metallogenic prediction of nonferrous metals and geological environment monitoring Ministry of EducationCentral South UniversityChangsha 410083China School of Resources and Safety Engineering Central South UniversityChangsha 410083China Center of Rock Mechanics and Geohazards Shaoxing UniversityShaoxing 312000China

Four groups of numerical models of Brazilian tests on rock-shotcrete interfaces were successfully conducted by PFC2D. The tensile strength and Young’s modulus of shotcrete were considered. Six different undulations of rock-shotcrete interface were set up. The influences of multiple parameters on the bearing characteristics of the rock-shotcrete interface were studied. The results showed that a better support performance can be obtained by increasing the Young’s modulus of shotcrete rather than the tensile strength of shotcrete. For different tensile strength and Young’s modulus, the increase of sawtooth height has different effects on the support performance. The failure mechanism of the rock-shotcrete interfaces was analysed in detail. The stress shielding effect and stress concentration effect caused by the shape characteristics of rock-shotcrete interface were observed. The influence of these parameters on the overall support performance should be fully considered in a reasonable support design.

关键词： Tensile strength PFC Shotcrete Fracturing behavior Rock interface

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Sources of rare earth elements REE+Y(REY)in Bayili Coal Mine from Wensu County of Xinjiang,China

引用

Transactions of nonferrous metals Society of China 2021年第10期31卷 3105-3115页

作者： Jian-qiang XUE Jian-xin LIU De-zhi HUANG Wei-jian ZHOU Chun-ming LIU Yu-sen CAO Chuang-hua CAO School of Geosciences and Info-physics Central South UniversityChangsha 410083China key laboratory of metallogenic prediction of nonferrous metals and geological environment monitoring Ministry of EducationCentral South UniversityChangsha 410083China Hunan Institute of Geology Survey Changsha 410011China

By analyses on the trace elements of coals,host-rocks and wall-rocks,this study aims to trace the sources and evaluate the utilization prospects of REE+Y(REY)in coals from Bayili Coal Mine(Wensu,Xinjiang,China).The distribution patterns of REY in the coals are divided into two groups,flat-type and heavy REE-enrichment type(H-type).The REY of the former was mainly from the gneisses of the basement of the coal-bearing basin,and that of the later was partly from hydrothermal *** host-rocks show two types of REY patterns,middle REE-enrichment type(M-type)and H-type,which are due to the injection of REY from acid terrestrial water and hydrothermal solution,*** all the coal samples are plotted into the promising area on the diagram of percentage of critical elements(REY_(def,rel))vs ratio of sum of critical elements to the sum of excessive elements(C_(outl))and half of the coal samples have high contents of Ga closing to the cut-off grade of Ga deposit as by-product,which indicate that the REY and Ga in Bayili Coal Mine are of utilization prospects as by-product.

关键词： source rare earth elements distribution pattern coal Wensu County(Xinjiang)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

3D Mineral Prospectivity Mapping Based on Deep metallogenic prediction Theory:A Case Study of the Lala Copper Mine,Sichuan,China

引用

Journal of Earth Science 2021年第2期32卷 348-357页

作者： keyan Xiao Jie Xiang Mingjing Fan Yang Xu MNR key laboratory of Metallogeny and Mineral Resource Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China International Mining research Center China Geological SurveyBeijing 100037China China Mining News China Geological SurveyBeijing 100037China Institute of geological Survey China University of GeosciencesWuhan 430074China China University of Geosciences Beijing 100083China

With the decrease in surface and shallow ore deposits,mineral exploration has focused on deeply buried ore bodies,and large-scale metallogenic prediction presents new opportunities and *** paper adopts the predictive thinking method in this era of big data combined with specific research on the special exploration and exploitation of deep-earth *** basic theoretical models of large-scale deep mineralization prediction and evaluation are explored:mineral prediction geological model theory,multidisciplinary information correlation theory,mineral regional trend analysis theory,and mineral prediction geological differentiation *** main workflow of large-scale deep resource prediction in the digital and information age is summarized,including construction of ore prospecting models of metallogenic systems,multiscale 3 D geological modeling,and 3 D quantitative prediction of deep *** the Lala copper mine in Sichuan Province as an example,this paper carries out deep 3 D quantitative prediction of mineral resources and makes a positive contribution to the future prediction and evaluation of mineral resources.

关键词： deep mine resources prospectivity mapping 3D modeling quantitative evaluation Lala copper mine

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Re-Os Isotopic Age of Molybdenite of the Jingren Deposit and its Mineralogical Significance of Magnetite,Pyrite and Chalcopyrite

引用

Acta Geologica Sinica(English Edition) 2021年第4期95卷 1236-1248页

作者： CAO Li YI Liwen DAI Wei XIE Binggeng LI Xiaoqing LU Anhuai GU Xiangping College of Geographic Sciences Hunan Normal UniversityChangsha 410081China key laboratory of metallogenic prediction of nonferrous metals and geological environment monitoring(Central South University) Ministry of EducationChangsha 410083China The Third of Qinghai geological and Mineral Exploration Institute Xining 810012China College of Geosciences and Info-Physics Central South UniversityChangsha 410083China

The Jingren deposit is part of the Qimantage metallogenic belt within the eastern Kunlun orogenic belt,the largest metallogenic belt in Qinghai Province,northwestern *** data show that the metal resources of the Jingren deposit are greater than 93000 t in a mining area of 76.15 km2,which indicates significant exploration potential in the near *** W–E-trending faults,F1-3,dominate the extension of the mineralization zone,which consists of chalcopyrite,pyrite,magnetite,galena,sphalerite,and molybdenite as well as bismuth-bearing *** deposit contains a large amount of late Triassic intrusive rocks,however,previous research did not reach a consensus on the timing or the origin of the mineralization owing to a lack of geochronological data and poor exposure *** the present study,Re-Os isotopic dating from six molybdenite samples collected from a borehole of the granodiorite in the Jingren deposit using negative thermal ionization mass spectrometry(NTIMS)showed 187 Re and 187 Os concentrations of 0.26–4.40 ppm and 1.03–16.46 ppb,respectively,with an initial 187 Os/188 Os value of 0.06±*** proves that the Jingren deposit has a metallogenic age of(225±4)Ma and is the product of united mineralization of the Qimantage metallogenic belt and that the Jingren deposit might actually be an Indosinian *** addition,the Re content of these samples,at 0.42 ppm to 7.00 ppm shows that the mineralization was derived mainly from a crustal ***,electron probe microanalysis(EPMA)conducted on chalcopyrite obtained from 22 metallic mineral samples revealed(Fe+Cu)/S ratios of 1.801–1.947 with an average of 1.852,which is lower than the ideal value(1.875).Besides,the main ore body formed in a relatively higher temperature environment than the surrounding rocks in the Jingren *** data indicate that the Jingren deposit formed in a metallogenic environment at lower ***,according to the TiO_(2)-Al_(2

关键词： mineralogy Re-Os isotopic dating molybdenite skarn Indosinian Jingren deposit Qimantage metallogenic belt

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A machine learning approach to tracking crustal thickness variations in the eastern North China Craton

引用

Geoscience Frontiers 2021年第5期12卷 215-223页

作者： Shaohao Zou Xilian Chen Deru Xu Matthew JBrzozowski Feng Lai Yubing Bian Zhilin Wang Teng Deng State key laboratory of Nuclear Resources and environment East China University of TechnologyNanchang 330013China key laboratory of metallogenic prediction of nonferrous metals and geological environment monitoring Ministry of EducationSchool of Geosciences and Info-PhysicsCentral South UniversityChangsha 410083China State key laboratory for Mineral Deposits research School of Earth Sciences and EngineeringNanjing UniversityNanjing 210023China

The variation of crustal thickness is a critical index to reveal how the continental crust evolved over its four billion ***,ratios of whole-rock trace elements,such as Sr/Y,(La/Yb)n and Ce/Y,are used to characterize crustal ***,sometimes confusing results are obtained since there is no enough filtered ***,a state-of-the-art approach,based on a machine-learning algorithm,is proposed to predict crustal thickness using global major-and trace-element geochemical data of intermediate arc rocks and intraplate basalts,and their corresponding crustal *** the validation processes,the root-mean-square error(RMSE)and the coefficient of determination(R2)score were used to evaluate the performance of the machine learning algorithm based on the learning dataset which has never been used during the training *** results demonstrate that the machine learning algorithm is more reliable in predicting crustal thickness than the conventional *** trained model predicts that the crustal thickness of the eastern North China Craton(ENCC)was-45 km from the Late Triassic to the Early Cretaceous,but-35 km from the Early Cretaceous,which corresponds to the paleo-elevation of 3.0±1.5 km at Early Mesozoic,and decease to the present-day elevation in the *** estimates are generally consistent with the previous studies on xenoliths from the lower crust and on the paleoenvironment of the coastal mountain of the ENCC,which indicates that the lower crust of the ENCC was delaminated abruptly at the Early Cretaceous.

关键词： Machine learning Geochemical database Crustal thickness Eastern North China Craton

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect on the Performance of Drilling Fluids at Downhole Rock Surfaces at Low Temperatures

引用

Journal of Earth Science 2016年第5期27卷 856-863页

作者： Mingming Zheng Guosheng Jiang Tianle Liu Fulong Ning Ling Zhang V.F.Chikhotkin key laboratory of metallogenic prediction of nonferrous metals and geological environment monitoring (Central South University) Ministry of Education Engineering faculty China university of Geosciences key Lab of Drilling and Exploitation Technology in Complex Conditions Jilin University

To maintain gas hydrate stability, low-temperature drilling fluids and high drilling speeds should be used while drilling in gas hydrate-bearing sediments. The effect of the drilling fluid on downhole rock surfaces at low temperatures is very important to increase the drilling rate. This paper analyzed the action mechanism of the drilling fluid on downhole rock surfaces and established a corresponding evaluation method. The softening effect of six simulated drilling fluids with 0.1 wt.% of four common surfactants and two common organic salts on the downhole rock surface strength was evaluated experimentally using the established method at low temperature. The experimental results showed that the surfactants and organic salts used in the drilling fluids aided in the reduction of the strength of the downhole rock surface, and the established evaluation method was able to quantitatively reveal the difference in the softening effect of the different drilling fluids through comparison with water. In particular, the most common surfactant that is used in drilling fluids, sodium dodecyl sulfate（SDS）, had a very good softening effect while drilling under low-temperature conditions, which can be widely applied during drilling in low-temperature formations, such as natural gas hydrate-bearing sediments, the deep seafloor and permafrost.

关键词： gas hydrate bearing sediments low temperature drilling fluid performances downholerock surface strength influence mechanism.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Experiments and Analysis of the Hydraulic Fracture Propagation Behaviors of the Granite with Structural Planes in the Gonghe Basin

引用

Acta Geologica Sinica(English Edition) 2021年第6期95卷 1816-1827页

作者： XIE Jingyu LI Lei WEN Dongguang PENG Suping ZHENG Jing FU Guoqiang Center for Hydrogeology and environmental Geology Survey China Geological SurveyTianjin 300309China State key laboratory of Coal Resources and Safe Mining China University of Mining and TechnologyTianjin 300309China key laboratory of metallogenic prediction of nonferrous metals and geological environment monitoring Central South University Ministry of EducationChangsha 410083China School of Geosciences and Info-Physics Central South UniversityChangsha 410083China School of Resources and Geosciences China University of Mining and TechnologyXuzhouJiangsu 221116China

Hydraulic fracture(HF) propagation behavior is significant when building enhanced geothermal systems(EGS). HF geometry is closely related to the structural planes(SPs) in hot dry rock(HDR), such as natural fractures(NFs), quartz veins(QVs) and lithologic interfaces(LIs). However, the HF behaviors in HDR have not been well understood, especially the influence of multiple SPs on the HF geometry. To clarify this mechanism, several groups of physical simulation experiments of hydraulic fracturing were conducted to investigate the intersection relationship between the HFs and the SPs. Results show that the HF geometry shows great differences when intersecting with different SPs. In summary, the HF geometry displays four basic patterns, namely, propagation along the SPs, branching, capture, penetration/non-dilation. The fluctuation degree of the pressure-time curve and the HF complexity show a positive correlation. The cementing strength of the SP and their different mechanical properties from rock matrix influence the HF behaviors significantly. Therefore, the HF shows diverse geometries when intersecting with the NFs and LIs, while propagating along the QV when intersecting with it. For the complex networks, it is favorable for the HF to penetrate through and dilate several SPs, rather than simply cross or propagate along the SP.

关键词： Corresponding author:LI Lei,E-mail:leileely@*** Corresponding author:ZHENG Jing,E-mail:zhengjing8628@***。

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Petrogenesis and Mineralization of Two-Stage A-Type Granites in Jiuyishan,South China:Constraints from Whole-rock Geochemistry, Mineral Composition and Zircon U-Pb-Hf Isotopes

引用

Acta Geologica Sinica(English Edition) 2019年第4期93卷 874-900页

作者： LIU Ye LAI Jianqing XIAO Wenzhou Dick JEFFREY DU Rijun LI Shuanglian LIU Chaoyun WEN Chunhua YU Xiaohang key laboratory of Metaallogenic prediction of nonferrous metals and geological Enironment monitoring Ministry of EducationCentral South UniversityChangsha 410083China School of Geosciences and Info-Physics Central South UniversityChangsha 410083China Hunan Institute of geological Survey Changsha 410116China College of Marine Science and Technology China University of GeosciencesWuhan 430074China

The Jiuyishan complex massif,located in the northern section of the Nanling region,is a combination of five plutons,namely,the Xuehuading,Jinjiling,Pangxiemu,Shaziling and Xishan ***-rock geochemistry,Imineral electron microprobe analysis,zircon U-Pb dating and Hf isotope analysis were carried out for the Jinjiling and Pangxiemu *** zircon U-Pb dating yields weighted mean ages of 152.9±0.9 Ma for the Jinjiling pluton and 151.7±1.5 Ma for the Pangxiemu pluton,with a narrow gap between *** Jinjiling and Pangxiemu plutons both have geochemical characteristics of high SiO2,Al2 O3,Na2 O,K2 O and low TiO2,MgO,CaO,P2 O5 contents,with intense depletions in Sr,Ba,Ti,Eu and enrichments in Ga,FeoOT and HFSE,and these characteristics reflect an A-type *** the Jinjiling to the Pangxiemu plutons,the mineral composition of mica changes from lepidomelane to zinnwaldite,with increases in F,Li2 O and Rb2 O *** mineral composition of zircon changes from low Zr/Hf to high Zr/Hf,with increasing HfO2,P2 O5 and UO2+ThO2+Y2 O3 *** mineral compositions of feldspar indicate that the Pangxiemu pluton contains more alkali feldspar than the Jinjiling *** whole-rock geochemistry and mineral compositions reveal a higher degree of differentiation for the Pangxiemu *** nearly uniformεHf(t)indicates the same source region for the two plutons:both were derived from partial melting of the lower crust,with small contributions of mantle *** addition,higher F,lower Nb/Ta and Zr/Hf ratios in the Pangxiemu Pluton suggest a closer relationship with the rare metal mineralization than for the Jinjiling pluton.

关键词： zircon U-Pb dating mineral composition A-type granite rare metal mineralization Jinjiling pluton Pangxiemu pluton

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：