摘要
对桂西那坡基性岩进行了铂族元素(PGE)地球化学研究,并与ELIP内带玄武岩进行对比,以揭示那坡基性岩成因及其演化过程。那坡高、低Ti基性岩PGE含量差别较大,高Ti基性岩PGE含量较高,分别为Ir(0. 063～0. 079)×10^(-9)、Ru(0. 047～0. 054)×10^(-9)、Rh(0. 153～0. 173)×10^(-9)、Pt(4. 183～4. 343)×10^(-9)、Pd(2. 7～2. 91)×10^(-9);低Ti基性岩PGE含量极低,分别为Ir(0. 005～0. 014)×10^(-9)、Ru(0. 008～0. 013)×10^(-9)、Rh(0. 003～0. 013)×10^(-9)、Pt(0. 064～0. 364)×10^(-9)、Pd(0. 055～0. 281)×10^(-9)。那坡高Ti基性岩具有与ELIP玄武岩相似的PGE含量及标准化配分特征,低Cu/Pd和高Pt/Y值;而那坡低Ti基性岩PGE含量及标准化配分特征完全不同于峨眉山玄武岩,具有低PGE含量,极高Cu/Pd和极低Pt/Y值,这些特征揭示了那坡高Ti基性岩PGE特征继承了峨眉山玄武岩地幔源区特征,而低Ti基性岩的PGE特征可能受到了峨眉山地幔柱和古特提斯俯冲作用的共同影响,是由峨眉山地幔柱与古特提斯软流圈地幔相互作用形成的。
Geochemistry study of platinum group element(PGE)was carried out on the Napo basic rock in western Guangxi,and compared with the basalt in ELIP to reveal the genesis and evolution of the basic rock.The PGE contents of the Napo high-Ti mafic rock and low-Ti mafic rock are quite different,high-Ti mafic rock is relatively rich in PGE(respectively,Ir(0.063-0.079)×10^-9,Ru(0.047-0.054)×10^-9,Rh(0.153-0.173)×10^-9,Pt(4.183-4.343)×10^-9,Pd(2.7-2.91)×10^-9)whereas low-Ti mafic rock is extremely poor in PGE(respectively,Ir(0.005-0.014)×10^-9,Ru(0.008-0.013)×10^-9,Rh(0.003-0.013)×10^-9,Pt(0.064-0.364)×10^-9,Pd(0.055-0.281)×10^-9).The results show that the primitive mantle normalized PGE patterns of Napo high-Ti mafic rock are similar to ELIP,and basalts with low Cu/Pd and high Pt/Y ratios when compared to Napo low-Ti mafic rock.However,Napo low-Ti mafic rock displays a different primitive mantle normalized PGE patterns and lower PGE abundance and Pt/Y ratios,importantly with extremely high Cu/Pd ratios when compared to Napo high-Ti mafic rock and ELIP basalts.These features suggest that Napo high-Ti mafic rock inherited the feature of the Emeishan mantle plume source,but distinctive PGE characteristics of the Napo low-Ti mafic rock indicate that they may be co-affected by Paleo-Tethys subduction system and Emeishan mantle plume and formed by interaction between Emeishan mantle plume and Paleo-Tethys asthenosphere mantle.
作者
招传
刘希军
时毓
刘磊
李政林
潘罗忠
胡荣国
王葆华
张治国
丁姗姗
ZHAO Chuan;LIU Xi-jun;SHI Yu;LIU Lei;LI Zheng-lin;PAN Luo-zhong;HU Rong-guo;WANG Bao-hua;ZHANG Zhi-guo;DING Shan-shan(Key laboratory for exploration of concealed metal minerals in Guangxi,Guilin university of technology,Guilin,Guangxi,541004;Cooperative innovation center for exploration and material development of concealed non-ferrous metal deposits in Guangxi,Guilin university of technology,Guilin,Guangxi,541004;Guangxi Institute of Regional Geological Survey,Guilin 541003,China)
出处
《桂林理工大学学报》
CAS
北大核心
2018年第4期680-687,共8页
Journal of Guilin University of Technology
基金
国家自然科学基金项目(41463002)
广西自然科学基金杰出青年科学基金项目(2018GXNSFFA281009)
广西自然科学基金项目(2017GXNSFBA198167)
广西研究生教育创新计划项目(YCSW2018151)
关键词
铂族元素
基性岩
ELIP
古特提斯
桂西
platinum-group elements
mafic rock
ELIP
Paleo-Tethys
western Guangxi
