期刊文献+
共找到6篇文章
< 1 >
每页显示 20 50 100
Majoritic Garnets:Key Clues to Kimberlite Formation in South China
1
作者 Yuhua Zhu William L.Griffin +8 位作者 Ruidong Yang Junbo Gao Lei Wang Yuren Zeng Jianshu Chen Miaoling He Hongjuan Rao Yonggang Li Jiawei Zhang 《Journal of Earth Science》 SCIE CAS CSCD 2024年第6期2133-2137,共5页
Kimberlite,which is the primary host rock for diamonds,originates from the deepest sources of all the mantle-derived magmas(Giuliani et al.,2023;Foley et al.,2019).This feature provides a vital perspective to explore ... Kimberlite,which is the primary host rock for diamonds,originates from the deepest sources of all the mantle-derived magmas(Giuliani et al.,2023;Foley et al.,2019).This feature provides a vital perspective to explore Earth's internal structure and evolution.The first primary diamond deposit discovered in China was the East No.1 kimberlite pluton(D1)in Maping(26°56′08″N,108°17′07″E),located on the southeastern margin of the Yangtze Craton(Figure 1). 展开更多
关键词 evolution MAGMA southeastern
原文传递
Transition-Zone Mineral Assemblages in Peridotite Massifs, Tibet: Implications for Collision-zone Dynamics and Orogenic Peridotites
2
作者 W. L. GRIFFIN N.M. MCGOWAN +7 位作者 J. M. GONZALEZ-JIMENEZ E. A. BELOUSOVA D. HOWELL J. C. AFONSO YANG J.S SHI R Suzanne Y. O'REILLY N. J. PEARSON 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2015年第A02期90-91,共2页
Diamonds have been reported from Tibetan "ophiolites" for 〉30 years, but have been widely dismissed as contaminants, because their unusual morphology and light C (δ13C=-18 to -27) are unlike those of kimberlitic... Diamonds have been reported from Tibetan "ophiolites" for 〉30 years, but have been widely dismissed as contaminants, because their unusual morphology and light C (δ13C=-18 to -27) are unlike those of kimberlitic diamonds. However, the diamonds have now been found in situ in both the chromitites and the peridotites of "ophiolites" along the Yarlung-Zangbo suture (Tibet) and the Polar Urals (Yang et al., 2014). 展开更多
下载PDF
Metasomatism-induced wehrlite formation in the upper mantle beneath the Nógrád-G?m?r Volcanic Field(Northern Pannonian Basin):Evidence from xenoliths
3
作者 Levente Patko Nora Liptai +9 位作者 Laszlo Elod Aradi Rita Klebesz Eszter Sendula Robert J.Bodnar Istvan Janos Kovacs Karoly Hidas Bernardo Cesare Attila Novak Balazs Trasy Csaba Szabo 《Geoscience Frontiers》 SCIE CAS CSCD 2020年第3期943-964,共22页
Clinopyroxene-enriched upper mantle xenoliths classified as wehrlites are common(~20% of all xenoliths) in the central part of the Nograd-G(o| ")m(o|")r Volcanic Field(NGVF),situated in the northern margin o... Clinopyroxene-enriched upper mantle xenoliths classified as wehrlites are common(~20% of all xenoliths) in the central part of the Nograd-G(o| ")m(o|")r Volcanic Field(NGVF),situated in the northern margin of the Pannonian Basin in northern Hungary and southern Slovakia.In this study,we thoroughly investigated 12 wehrlite xenoliths,two from each wehrlite-bearing occurrence,to determine the conditions of their formation.Specific textural features,including clinopyroxene-rich patches in an olivine-rich lithology,orthopyroxene remnants in the cores of newlyformed clinopyroxenes and vermicular spinel forms all suggest that wehrlites were formed as a result of intensive interaction between a metasomatic agent and the peridotite wall rock.Based on the major and trace element geochemistry of the rock-forming minerals,significant enrichment in basaltic(Fe,Mn,Ti) and high field strength elements(Nb,Ta,Hf,Zr) was observed,compared to compositions of common lherzolite xenoliths.The presence of orthopyroxene remnants and geochemical trends in rock-forming minerals suggest that the metasomatic process ceased before complete wehrlitization was achieved.The composition of the metasomatic agent is interpreted to be a mafic silicate melt,which was further confirmed by numerical modelling of trace elements using the plate model.The model results also show that the melt/rock ratio played a key role in the degree of petrographic and geochemical transformation.The lack of equilibrium and the conclusions drawn by using variable lherzolitic precursors in the model both suggest that wehrlitization was the last event that occurred shortly before xenolith entrainment in the host mafic melt.We suggest that the wehrlitization and the Plio-Pleistocene basaltic volcanism are related to the same magmatic event. 展开更多
关键词 WEHRLITE XENOLITHS Upper MANTLE METASOMATISM MAFIC silicate melt Trace element modelling
下载PDF
Sulfide Aggregation in Ophiolitic Dunite Channels Explains Os-Isotope Mismatch between Oceanic Crust and Mantle
4
作者 XIONG Qing XU Yong +5 位作者 José M.GONZÁLEZ-JINÉNEZ LIU Jingao Olivier ALARD ZHENG Jian-Ping William L.GRIFFIN Suzanne Y.O’REILLY 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2020年第S01期66-66,共1页
The osmium-isotope mismatch commonly reported between mid-ocean-ridge basalts(MORBs) and residual mantle might reflect evolution of the MORB Re-Os system after extraction from the asthenosphere, or preferential contri... The osmium-isotope mismatch commonly reported between mid-ocean-ridge basalts(MORBs) and residual mantle might reflect evolution of the MORB Re-Os system after extraction from the asthenosphere, or preferential contribution of radiogenic Os components from mantle. However, in a MOR system, the role of dunite melt channels from the upper mantle and Moho transition zone in regulating isotopic systems between mantle and crust has rarely been evaluated. We report new Re-Os isotopic compositions of base-metal sulfides(BMS), chromites and dunites from dunite lenses with low spinel Cr# [Cr3+/(Cr3++Al3+) ≤ 0.66](products of interaction between MORB-like melts and upper-mantle harzburgites) from the Zedang ophiolite(South Tibet). Re-Os isotopic compositions of low-Cr# dunites from the Oman ophiolite are also shown for comparison. Mineralogical evidence suggests that the Zedang sulfides were originally precipitated as monosulfide solid solutions. The highly variable 187Os/188Os initial ratios(0.1191-0.1702) and low 187Re/188Os(<0.22) of the sulfides suggest that the chromite acted as a sink for Os-bearing sulfides, aggregating discrete Os components with heterogeneous isotopic signatures from asthenospheric or lithospheric mantle into dunite channels. The Zedang chromites and dunites show 187Os/188Os ratios similar to the primitive upper mantle(PUM), except for two dunites with sub-PUM ratios, reflecting the contribution of Os balanced by smaller volumes of Os-rich, unradiogenic sulfides(likely nucleating on Os nanoparticles) and larger volumes of Os-poor radiogenic BMS. Such isotopic heterogeneity, despite with less variation, has been observed in dunite channels from the Oman ophiolite and present-day mid-ocean ridges. Formation of dunite channels in the upper mantle thus can aggregate Os-bearing sulfides with chromite, leaving high Re/Os components into the residual melts. Once such channel systems were built up at the crust-mantle transition zone, the newly incoming MOR magmas would preferentially melt and dissolve t 展开更多
关键词 sulfide aggregation dunite melt channels Re-Os isotopes Os-isotope mismatch of oceanic crust and mantle melt plumbing system mid-ocean ridges
下载PDF
Diamonds and Highly Reduced Minerals from Chromitite of the Ray-Iz Ophiolite of the Polar Urals: Deep Origin of Podiform Chromitites and Ophiolitic Diamonds
5
作者 YANG J.S WIRTH R +7 位作者 WIEDENBECK M GRIFFIN W.L MENG F.C CHEN S.Y BAI W.J XU X.X MAKEEYEV A.B BRYANCHANINIOVA N.I 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2015年第A02期107-107,共1页
The Uralide orogenic belt suture zone extending more is a major early Paleozoic than 3000 km in a N-S direction, and geographically divides Europe from Asia (Chemenda et al., 1997). Ophiolites, podiform chromitites ... The Uralide orogenic belt suture zone extending more is a major early Paleozoic than 3000 km in a N-S direction, and geographically divides Europe from Asia (Chemenda et al., 1997). Ophiolites, podiform chromitites and high pressure metamorphic rocks are well developed in the orogenic belt (Leech and Ernst, 2000). 展开更多
下载PDF
Porphyry Cu deposits linked to episodic growth of an underlying parental magma chamber 被引量:3
6
作者 Yuanchuan ZHENG Lu WANG +7 位作者 Chuandong XUE Bo XU Abdul GHAFFAR Zhusen YANG Yongjun LU Limin ZHOU William L.GRIFFIN Zengqian HOU 《Science China Earth Sciences》 SCIE EI CAS CSCD 2020年第11期1807-1816,共10页
Saindak is one of the typical porphyry Cu deposits(PCDs)in the Chagai magmatic arc in Pakistan.Ore-forming porphyries at Saindak PCD are mainly composed of tonalite.Here,we use geochemistry of apatite enclosed in plag... Saindak is one of the typical porphyry Cu deposits(PCDs)in the Chagai magmatic arc in Pakistan.Ore-forming porphyries at Saindak PCD are mainly composed of tonalite.Here,we use geochemistry of apatite enclosed in plagioclase phenocrysts from the ore-forming tonalite to constrain the releasing and recharging processes of S and Cl in the underlying parental magma chamber during PCD mineralization.Although apatite inclusions have homogeneous intra-grain S and Cl compositions,there is significant inter-grain S and Cl variations in apatite inclusions located from core to rim in the hosting plagioclase.Such inter-grain S and Cl variation in apatites are coupled with the core-to-rim trends of An,FeO and Mg contents of the hosting plagioclase phenocryst.It indicates that the Saindak PCD likely formed by episodic injection of primitive magmas during the growth of an underlying magma chamber,rather than by one major injection or by addition of mafic melt derived from different source region.Each primitive melt injection introduced essential ore-forming materials such as S and Cl,which were rapidly and effectively released to the coexisting fluids,causing mineralization.Once primitive melt injection stops,signaling the end of growth of underlying magma chamber,mineralization will cease quickly although the hydrothermal system can still survive for a long time.However,the later released fluids are relatively depleted in ore-forming materials,and thus have lower capability to generate mineralization.Accordingly,predominant porphyry-type mineralizations occurred during the growth rather than waning stage of a magmatic system. 展开更多
关键词 APATITE PLAGIOCLASE Episodic injection Parental magma chamber Porphyry Cu deposit
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部