川西里伍岩群中石榴子石矿物化学特征及其对变质温度的限定

Mineral Chemical Characteristics and Constraint on Metamorphic Temperature of Garnet from the Liwu Group,Western Sichuan,China

黄驰轩 ¹谭洪旗 ²杨玉龙 ³王强 ³胡军亮 ¹唐尧³

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作者信息

1. 成都理工大学地球科学学院,四川成都 610059;中国地质科学院矿产综合利用研究所,中国地质调查局稀土资源应用技术创新中心,四川成都 610041
2. 四川省地质矿产(集团)有限公司,四川成都 610016
3. 成都理工大学地球科学学院,四川成都 610059
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摘要

这是一篇地球科学领域的论文.为揭示江浪穹隆核部里伍岩群中石榴子石的矿物化学特征及其变质温度,本文选择了发育在不同位置的石榴子石矿物开展了主量、微量和稀土元素分析测试.结果表明,江浪穹隆片岩中的石榴子石端元组成主要为铁铝榴石(Alm),利用ICP-MS(平均含量85.82％)和LA-ICP-MS(平均含量83.51％)获得的铁铝榴石(Alm)含量在误差范围内基本一致;稀土元素(REE)总量较高,分配模式呈现明显的轻稀土亏损(LREE)、重稀土(HREE)富集的左倾分配模式,Eu异常不明显,负Ce异常显著;相对富集高场强元素(如U、Ta、Hf),亏损大离子亲石元素(如K、Sr、Ba).另外,江浪穹隆片岩中利用石榴子石矿物获得的变质温度为512～583 ℃,形成的变质压力较低,且变质温度与至新火山花岗岩的距离呈负相关关系.综上,江浪穹隆经历了高绿片岩相的巴罗式变质作用.

Abstract

This is an article in the field of earth sciences.To reveal the mineral chemistry characteristics and metamorphic temperature of garnet in the Liwu Group due to core of Jianglang dome,the major,trace and rare earth elements of garnet were analyzed at different locations in this paper.The results show that the major-element composition of garnet in schist from the Jianglang dome is mainly Alm.ICP-MS(average content 85.82％)and LA-ICP-MS(average content 83.51％)is basically consistent within the error range of the Alm content obtained.The total content of rare earth elements(REE)is high,and show obvious LREE-depleted and HREE-enriched left-declined REE distribution patterns,with unobvious Eu anomalies and negative Ce anomalies,Enriched in large ionic strength elements(U,Ta,Hf)and depleted high field lithophile elements(K,Sr,Ba).In addition,the formation temperature of garnet in schist from the Jianglang dome is 512～583 ℃,and the formed metamorphic pressure is relatively low.It is a negative correlation between the metamorphic temperature and the distance to the Xinhuoshan granite.In conclusion,the Jianglang dome experienced"Barrovian-type"metamorphism of high greenschist facies.

关键词

地球科学/石榴子石/矿物化学/里伍岩群/江浪穹隆

Key words

Earth sciences/Garnet/Mineral chemistry/Liwu Group-complex/Jianglang dome

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基金项目

国家自然科学基金项目(41603034)

中国地质调查局项目(DD20221697)

出版年

2024

矿产综合利用

中国地质科学院矿产综合利用研究所

矿产综合利用

CSTPCD

影响因子：0.643

ISSN：1000-6532

参考文献量35

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