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Time scales and length scales in magma ?ow pathways and the origin ofmagmatic Ni-Cu-PGE ore deposits

Geoscience Frontiers 2019年第1期10卷 77-87页

作者： stephen j.barnes jesse C.Robertson CSIRO Mineral Resources

Ore forming processes involve the redistribution of heat, mass and momentum by a wide range of processes operating at different time and length scales. The fastest process at any given length scale tends to be the dominant control. Applying this principle to the array of physical processes that operate within magma flow pathways leads to some key insights into the origins of magmatic Ni-Cu-PGE sulfide ore deposits. A high proportion of mineralised systems, including those in the super-giant Noril'sk-Talnakh camp, are formed in small conduit intrusions where assimilation of country rock has played a major role. Evidence of this process is reflected in the common association of sulfides with varitextured contaminated host rocks containing xenoliths in varying stages of assimilation. Direct incorporation of S-bearing country rock xenoliths is likely to be the dominant mechanism for generating sulfide liquids in this setting. However, the processes of melting or dissolving these xenoliths is relatively slow compared with magma flow rates and, depending on xenolith lithology and the composition of the carrier magma, slow compared with settling and accumulation rates. Chemical equilibration between sulfide droplets and silicate magma is slower still, as is the process of dissolving sulfide liquid into initially undersaturated silicate magmas. Much of the transport and deposition of sulfide in the carrier magmas may occur while sulfide is still incorporated in the xenoliths, accounting for the common association of magmatic sulfide-matrix ore breccias and contaminated "taxitic" host rocks. Effective upgrading of so-formed sulfide liquids would require repetitive recycling by processes such as reentrainment, back flow or gravity flow operating over the lifetime of the magma transport system as a whole. In contrast to mafic-hosted systems, komatiite-hosted ores only rarely show an association with externally-derived xenoliths, an observation which is partially due to the pre

关键词： Magmatic ore deposits Assimilation Intrusions Nickel Norilsk Komatiites

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An Elevated Perspective: Dyke-Related Fracture Networks Analysed with Uav Photogrammetry

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Acta Geologica Sinica(English Edition) 2016年第S1期90卷 54-55页

作者： Gregory DERING Steven MICKLETHWAITE stephen j.barnes Marco FIORENTINI Alexander CRUDEN Eric TOHVER School of Earth Sciences ARC Centre of Excellence for Core to Crust Fluid Systems University of Western Australia Mineral Resources Flagship CSIRO School of Earth Atmosphere and Environment Monash University

An abundance of data from seismic and geodetic monitoring has provided new insight into dyke propagation and emplacement *** studies show that faulting and fracturing is part of the magma

关键词： rock An Elevated Perspective Dyke-Related Fracture Networks Analysed with Uav Photogrammetry

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Zircon age depth-profiling sheds light on the early Caledonian evolution of the Seve Nappe Complex in west-central j?mtland

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Geoscience Frontiers 2022年第2期13卷 460-470页

作者： Katarzyna Walczak Christopher j.barnes jaroslaw Majka David G.Gee Iwona Klonowska AGH University of Science and Technology Faculty of GeologyGeophysics and Environmental Protectional.Mickiewicza 3030-059 KrakówPoland Uppsala University Department of Earth SciencesVillavagen 16752-36 UppsalaSweden

The Scandinavian Caledonides comprise nappe stacks of far-travelled allochthons that record closure of the Iapetus Ocean and subsequent continental collision of Baltica and *** Seve Nappe Complex(SNC)of the Scandinavian Caledonides includes relics of the outermost Baltoscandian passive margin that were subducted to mantle *** earliest of the deep subduction events has been dated to ca.500-480 *** of this event has been reported from the northern exposures of the *** south in the central and southern segments of the SNC,(ultra)high-pressure rocks have yielded younger ages in the range of ca.470-440 *** study provides the first record of the early Caledonian event in the southern *** evidence has been obtained by depth profiling of zircon grains that were extracted from the Tv?r?klumparna microdiamond-bearing *** zircon grains preserve eclogite facies overgrowths that crystallized at 482.6±3.8 Ma.A second,chemically-distinct zircon overgrowth records granulite facies metamorphism at 439.3±3.6 Ma,which corroborates previous geochronological evidence for granulite facies metamorphism at this *** on these results,we propose that the entire outer margin of Baltica was subducted in the late Cambrian to early Ordovician,but the record of this event may be almost entirely eradicated in the vast majority of lithologies by pervasive late Ordovician to early Silurian metamorphism.

关键词： Caledonian Orogeny Seve Nappe Complex Zircon geochronology Depth profiling HP/UHP metamorphism Double dunking

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Element mapping the Merensky Reef of the Bushveld Complex

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Geoscience Frontiers 2021年第3期12卷 259-278页

作者： William Smith Wolfgang Maier stephen barnes Gareth Moorhead David Reid Bartosz Karykowski School of Earth and Ocean Sciences Cardiff UniversityCardiff CF240DEUnited Kingdom CSIRO Mineral Resources Perth 6160Australia CSIRO ClaytonVictoriaAustralia University of Cape Town South Africa Fugro Germany Land GmbH 12555 BerlinGermany

The Merensky Reef hosts one of the largest PGE resources *** has been exploited for nearly 100 years,yet its origin remains *** the present study,we characterised eight samples of the reef at four localities in the western Bushveld Complex using micro-X-ray fluorescence and field emission scanning electron *** results indicate that the Merensky Reef formed through a range of diverse *** exhibited by chromite grains at the base of the reef are consistent with supercooling and in situ *** local thickening of the Merensky chromitite layers within troughs in the floor rocks is most readily explained by granular *** and deformation textures in pyroxenes of the Merensky pegmatoid bear testament to recrystallisation and *** footwall rocks to the reef contain disseminations of PGE rich sulphides as well as olivine grains with peritectic reaction rims along their upper margins suggesting reactive downward flow of silicate and sulphide ***-hosted melt inclusions containing Cl-rich apatite,sodic plagioclase,and phlogopite suggest the presence of highly evolved,volatile-rich *** reverse zonation of cumulus plagioclase in the footwall of the reef indicates dissolution or partial melting of plagioclase,possibly triggered by flux of heat,acidic fluids,or hydrous ***,these data suggest that the reef formed through a combination of magmatic,hydrodynamic and hydromagmatic processes.

关键词： Merensky Reef Bushveld Complex Magmatic sulphide Platinum-group elements PGE Anorthosite

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加拿大Quetico沉积变质带中亚固相浅色体与深熔混合岩浅色体的时间及成分的差异

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地质科技情报 1989年第3期8卷 19-25页

作者： E.W.Sawyer S.-j.barnes 王河锦

Quetico沉积变质带中的混合岩含有两类浅色体:1.顺层浅色体:它们是在变形作用与前进变质作用中产生的.与 Quetico沉积变质物相比较,这些浅色体富含sio_2、Sr和Eu,而贫Tio_2、Fe_2O_3、MgO、Cs、Rb、REE、Sc、Th、Zr及Hf.2.切层浅色体:... 详细信息

Quetico沉积变质带中的混合岩含有两类浅色体:1.顺层浅色体:它们是在变形作用与前进变质作用中产生的.与 Quetico沉积变质物相比较,这些浅色体富含sio_2、Sr和Eu,而贫Tio_2、Fe_2O_3、MgO、Cs、Rb、REE、Sc、Th、Zr及Hf.2.切层浅色体:它们形成于区域性褶皱事件之后,此时变质温度正值其峰值.与Quetico沉积变质物相比,这些浅色体富含Rb、Ba、Sr和Eu,且LREE、Th、Zr和Hf的含量变化较大.顺层浅色体是由一种称为构造分结作用的亚固相过程所形成的.这种由应力导致的块体转移过程于Quetico沉积变质物被埋藏而发生变形时就己开始,并在岩石经受应力和非均质化的过程中一直都在持续进行,亚固相浅色体的成分是与在压溶作用下经主岩活化作用而来的石英和长石相一致的.切层浅色体是在变质带的抬升过程中由Quetico沉积变质岩的部分熔融所形成的.在浅色体侵位过程中,由于结晶分馏作用而使深熔浅色体的成分有很大变化.有些深熔浅色体保存了初始熔体的成分,并具有平滑的REE型式,而具负EU异常的那些则代表分馏熔体,其它具有正EU异常的深熔浅色体则代表长石与所俘获对熔体的聚集.

关键词： Quetico 沉积变质混合岩初始熔体变质作用切层侵位变质带变形作用部分熔融

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Release, Recycle, Rebuild： Cell-Wall Remodeling, Autodegradation, and Sugar Salvage for New Wall Biosynthesis during Plant Development

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Molecular Plant 2018年第1期11卷 31-46页

作者： William j. barnes Charles T. Anderson Department of Biology Center for Ugnocellulose Structure and Formation The Pennsylvania State University University Park PA 16802 USA

Plant cell walls contain elaborate polysaccharide networks and regulate plant growth, development, mechanics, cell-cell communication and adhesion, and defense. Despite conferring rigidity to support plant structures, the cell wall is a dynamic extracellular matrix that is modified, reorganized, and degraded to tightly control its properties during growth and development. Far from being a terminal carbon sink, many wall polymers can be degraded and recycled by plant cells, either via direct re-incorporation by trans- glycosylation or via internalization and metabolic salvage of wall-derived sugars to produce new precur- sors for wall synthesis. However, the physiological and metabolic contributions of wall recycling to plant growth and development are largely undefined. In this review, we discuss long-standing and recent evi- dence supporting the occurrence of cell-wall recycling in plants, make predictions regarding the develop- mental processes to which wall recycling might contribute, and identify outstanding questions and emerging experimental tools that might be used to address these questions and enhance our understanding of this poorly characterized aspect of wall dynamics and metabolism.

关键词： Plant cell walls wall degradation wall recycling wall biosynthesis

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COPD疾病中的小气道问题

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中国处方药 2004年第12期3卷 34-35页

作者： Peter j.barnes 谢单丹

慢性阻塞性肺疾病(COPD)是一个不断扩大化的全球性主要疾病问题.1990年它在全球常见致死病因中列第六位,而疾病的全球性负荷研究报告预测到2020年它会成为全球疾病的第三大死因.COPD也影响了人们的正常工作,使得人们的医疗费用不断增加... 详细信息

慢性阻塞性肺疾病(COPD)是一个不断扩大化的全球性主要疾病问题.1990年它在全球常见致死病因中列第六位,而疾病的全球性负荷研究报告预测到2020年它会成为全球疾病的第三大死因.COPD也影响了人们的正常工作,使得人们的医疗费用不断增加,目前花费在COPD的医疗支出已超过了哮喘的支出.然而在所有的普通疾病中,COPD显然是被相对忽略的,对它致病的细胞和分子机制的研究投资少,且目前没有任何可减缓疾病不断恶化的治疗方案出台.

关键词： COPD 小气道疾病常见医疗支出正常哮喘问题增加扩大化

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Hemodynamic improvement using methylene blue after calcium channel blocker overdose

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World journal of Emergency Medicine 2019年第1期10卷 55-58页

作者： Sophia Ahmed Stacey barnes St.joseph's Regional Medical Center

Dear editor,Calcium channel blocker overdoses are often fatal despite standard treatment. Methylene blue is a novel adjunct that should be considered in refractory *** accepted therapeutic modalities include intraveno... 详细信息

关键词：小学英语课外阅读阅读材料

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Reply:Is the evolution of tumors Darwinian or non-Darwinian?

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National Science Review 2018年第1期5卷 17-19页

作者： Marc j Williams Benjamin Werner Chris P barnes Trevor A Graham Andrea Sottoriva Evolution and Cancer Laboratory Barts CancerInstitute Queen Marry University of London Department of Cell and Developmental Biology University College London Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX) University College London Centre for Evolution and Cancer The Institute of Cancer Research Department of Genetics Evolution and EnvironmentUniversity College London

Wu and colleagues’letter discusses the limitations of the use of a single sample per tumor to investigate neutral evolution in human *** evolution describes the situation in which there is no differential clonal selection amongst the population of cells within a cancer:all mutations thataccrue during growth are passengers and all drivers were already present in the

关键词： Reply:Is the evolution of tumors Darwinian or non-Darwinian VAF

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慢性阻塞性肺疾病的治疗前景

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中华医学杂志 2006年第41期86卷 2884-2886页

作者： Peter j.barnes 英国伦敦皇家学院国际心肺研究所

目前治疗慢性阻塞性肺疾病(COPD)的方法非常有限,尚无能够减缓病情发展和功能损伤的有效措施。因此,许多制药公司都纷纷致力于探索并研发新的、更有效的、能从根本上控制疾病进展的药物。[第一段]

关键词：慢性阻塞性肺疾病治疗前功能损伤病情发展制药公司疾病进展前治疗

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