Zoned orthopyroxenes in the Ni-Co sulfide ore-bearing Xiarihamu mafic-ultramafic intrusion in northern Tibetan Plateau, China: Implications for multiple magma replenishments

被引:17
作者
Wang, Kai-Yuan [1 ,2 ]
Song, Xie-Yan [1 ]
Yi, Jun-Nian [3 ]
Barnes, Stephen J. [4 ]
She, Yu-Wei [5 ]
Zheng, Wen-Qin [1 ]
Schoneveld, Louise E. [4 ]
机构
[1] Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, 99 Lincheng West Rd, Guiyang 550081, Guizhou, Peoples R China
[2] Univ Chinese Acad Sci, Beijing 100049, Peoples R China
[3] Guizhou Normal Univ, Inst Ecol Civilizat Karst Area, Guiyang, Guizhou, Peoples R China
[4] CSIRO Mineral Resources, Perth, WA 6151, Australia
[5] Chinese Acad Geol Sci, Inst Geol, Lab Isotope Geol, Minist Land & Resources, Beijing 100037, Peoples R China
关键词
The Xiarihamu mafic-ultramafic intrusion; Orthopyroxene zoning; Crystal size distribution; Cumulate; Magma replenishment; CRYSTAL SIZE-DISTRIBUTION; FE-MG INTERDIFFUSION; KUNLUN OROGENIC BELT; CU-PGE DEPOSITS; EAST-KUNLUN; DISTRIBUTION CSD; FIELD RELATIONSHIPS; WESTERN-AUSTRALIA; MELT COMPOSITION; ORTHO-PYROXENE;
D O I
10.1016/j.oregeorev.2019.103082
中图分类号
P5 [地质学];
学科分类号
0709 ; 081803 ;
摘要
The Xiarihamu mafic-ultramafic intrusion is situated in the East Kunlun Orogenic Belt (E-KOB), northern Tibetan Plateau, China, with Ni-Co sulfide mineralization mainly in orthopyroxenite and olivine orthopyroxenite. Wholerock and mineral compositions show cyclic variations in drill-hole intersections through the Xiarihamu mafic-ultramafic intrusion. Microbeam X-ray fluorescence (XRF) mapping shows reverse zoning (Cr-poor core, Cr-rich rim) and oscillatory zoning (Cr-poor core, Cr-rich mantle and Cr-poor rim) in orthopyroxene of olivine orthopyroxenite and orthopyroxenite. Zoned orthopyroxenes are euhedral or subhedral, and there are relatively sharp interfaces between zones with distinct Cr contents. Crystal-size distribution (CSD) curves of orthopyroxenes in olivine orthopyroxenite show concave-upward curvature at size larger than 3.0 mm, and larger orthopyroxenes commonly display zoning, implying a secondary recrystallization and grain growth of larger orthopyroxenes. Quantitative analyses show that Cr and enstatite contents of cores are relatively lower, but incompatible element (e.g., Ti, Zr, Ga and Sr) contents of cores are higher than rims in reverse zoned orthopyroxenes, and chemical profiles of unzoned orthopyroxenes resemble those of rims (but different from those of cores) in reverse zoned orthopyroxenes. Chemical profiles of orthopyroxenes indicate that Cr zoning is not due to the change in Cr partitioning behavior between orthopyroxene and silicate melt, which shows significant temperature and redox dependence. Textural feature and crystal-size distribution of orthopyroxenes suggest the formation of Cr-rich zones attests to the multi-stage growth in the process of magma replenishment, rather than a reactive liquid flow model or in-situ trapped liquid overgrowth. Orthopyroxene zoning, together with compositional variation and intrusive relationship between olivine orthopyroxenite and orthopyroxenite imply that the Xiarihamu mafic-ultramafic intrusion was formed by multiple magma replenishments with magma varying roughly from a more evolved to a more primitive composition.
引用
收藏
页数:19
相关论文
共 106 条
[1]  
[Anonymous], 1999, Geoscience-Journal of China University of Geosciences, DOI DOI 10.1006/MCPR.1998.0211
[2]  
[Anonymous], 2007, Orogenic Plateau: Terrane Amalgamation, Collision and Uplift in the Qinhai-Tibet Plateau
[3]   Origin of Reverse Zoned Cr-Spinels from the Paleoproterozoic Yanmenguan Mafic-Ultramafic Complex in the North China Craton [J].
Bai, Yang ;
Su, Ben-Xun ;
Xiao, Yan ;
Lenaz, Davide ;
Sakyi, Patrick Asamoah ;
Liang, Zi ;
Chen, Chen ;
Yang, Sai-Hong .
MINERALS, 2018, 8 (02)
[4]  
Barnes S.J., 2005, EC GEOLOGY 100 ANNIV, P179, DOI DOI 10.5382/AV100.08
[5]   THE DISTRIBUTION OF CHROMIUM AMONG ORTHO-PYROXENE, SPINEL AND SILICATE LIQUID AT ATMOSPHERIC-PRESSURE [J].
BARNES, SJ .
GEOCHIMICA ET COSMOCHIMICA ACTA, 1986, 50 (09) :1889-1909
[6]   THE PERSEVERANCE ULTRAMAFIC COMPLEX, WESTERN-AUSTRALIA - THE PRODUCT OF A KOMATIITE LAVA RIVER [J].
BARNES, SJ ;
HILL, RET ;
GOLE, MJ .
JOURNAL OF PETROLOGY, 1988, 29 (02) :305-331
[8]   Sulfide-silicate textures in magmatic Ni-Cu-PGE sulfide ore deposits: Massive, semi-massive and sulfide-matrix breccia ores [J].
Barnes, Stephen J. ;
Staude, Sebastian ;
Le Vaillant, Margaux ;
Pina, Ruben ;
Lightfoot, Peter C. .
ORE GEOLOGY REVIEWS, 2018, 101 :629-651
[9]   INTERSPINIFEX Ni SULFIDE ORE FROM THE CORONET SHOOT, KAMBALDA: CHARACTERIZATION USING MICROBEAM X-RAY FLUORESCENCE MAPPING AND 3-D X-RAY COMPUTED TOMOGRAPHY [J].
Barnes, Stephen J. ;
Beresford, Steve W. ;
Le Vaillant, Margaux .
ECONOMIC GEOLOGY, 2016, 111 (06) :1509-1517
[10]   Poikilitic Textures, Heteradcumulates and Zoned Orthopyroxenes in the Ntaka Ultramafic Complex, Tanzania: Implications for Crystallization Mechanisms of Oikocrysts [J].
Barnes, Stephen J. ;
Mole, David R. ;
Le Vaillant, Margaux ;
Campbell, Matthew J. ;
Verrall, Michael R. ;
Roberts, Malcolm P. ;
Evans, Noreen J. .
JOURNAL OF PETROLOGY, 2016, 57 (06) :1171-1198