中国大陆岩石圈地幔镍-钴-铂族元素组成及其成矿意义:地幔捕虏体证据  

The chemical compositions of the Ni,Co and platinum group elements beneath subcontinental lithosphere mantle in China and their metallogenic significance:Evidence from mantle xenoliths

作　　者：包亚文 张铭杰 徐文博 王新博 徐琦 胡沛青 林阿兵 BAO YaWen;ZHANG MingJie;XU WenBo;WANG XinBo;XU Qi;HU PeiQing;LIN ABing(Gansu Key Laboratory of Mineral Resources in Western China,School of Earth Sciences,Lanzhou University,Lanzhou 730000,China;School of Materials and Energy,Electron Microscopy Centre,Lanzhou University,Lanzhou,730000,China.;State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi an 710069,China)

机构地区：[1]兰州大学地质科学与矿产资源学院,甘肃省西部矿产资源重点实验室,兰州730000 [2]兰州大学电镜中心,材料与能源学院,兰州730000 [3]西北大学地质学系,大陆动力学国家重点实验室,西安710069

出　　处：《岩石学报》2022年第12期3835-3852,共18页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(91962212、41872075、42272069、40873005);国家重点研发计划项目(2022YFC2903504);第二次青藏高原综合科学考察(2019QZKK0704)联合资助.

摘　　要：镍、钴和铂族元素(PGEs,Platinum group elements)是我国紧缺的关键金属,它们作为亲铁元素主要储存在地核和地幔中。幔源岩浆作用能否超常富集镍、钴和铂族成矿在一定程度上取决于地幔源区这些元素的组成与富集程度,地幔捕虏体可揭示中国大陆岩石圈地幔镍、钴和铂族元素的组成与含量。本文总结了中国华北克拉通、华南克拉通和中亚造山带东部等主要构造单元地幔捕虏体中镍、钴和铂族元素的组成与含量,认为:(1)华北和华南克拉通岩石圈地幔镍、钴和铂族元素原始含量较高,高于原始地幔,且随深度增加而增加,是镍、钴和铂族元素成矿岩浆的有利地幔源区;(2)镍、钴和铂族元素以纳米原子团簇、合金或硫化物等形式赋存、运移与富集;(3)不同构造单元岩石圈地幔镍、钴和铂族元素的富集程度不同;(4)岩石圈地幔镍、钴和铂族元素含量从元古代到新生代有所降低,意味着该区存在镍、钴和铂族元素抽取的岩浆事件,故其成矿潜力巨大。The nickel,cobalt and platinum group elements(PGEs)are the critical metals of resource shortage in China,which are stored as highly siderophile elements in the earth s core as well as mantle.Whether Ni-Co-PGE can be enriched in mantle-derived magmatism as magmatic deposits depend partly on their compositions and enrichment beneath the subcontinental lithosphere mantle(SCLM).The mantle xenoliths hosted in Cenozoic-Mesozoic basalts and Paleozoic kimberlites in China provide direct evidence for revealing the consititute of the Ni-Co-PGE and their contents in the SCLM of China.This paper summarizes the components and contents of Ni,Co and PGEs in mantle xenoliths from different tectonic units,such as the North China Craton,the South China Craton and the eastern part of the Central Asian orogenic belt.The results show that:(1)The SCLM in the North China and South China cratons had high original contents of Ni,Co and PGE,i.e.,higher than the values in primitive mantle,and the contents of PGEs tend to increase with the depth.The SCLM of the North China and South China cratons are favorable mantle source for the formation of Ni,Co and PGE magmatic deposits.(2)Ni,Co and PGE could occur and be transported as nano element-clusters,alloy or immiscible sulfide melt in the mantle source.(3)Contents of Ni,Co and PGE in the SCLM vary in different regions.(4)The SCLM of the North China Craton may decrease in PGEs contents from Paleozoic to Cenozoic,i.e.,the magmatic events of Ni,Co and PGEs melt extraction should happenin the North China Craton,which means huge potentials of Ni,Co and PGE mineralization.

关 键 词：镍 钴 铂族元素 地幔捕虏体 大陆岩石圈地幔 中国 

分 类 号：P611.1[天文地球—矿床学] P618.53[天文地球—地质学]