U-Pb zircon ages of the host rocks of the Juomasuo Au-Co-Cu deposit, northeastern Finland

IF 1.3 4区 地球科学 Q2 GEOLOGY
P. Nikkola, I. Mänttäri, O. T. Rämö
{"title":"U-Pb zircon ages of the host rocks of the Juomasuo Au-Co-Cu deposit, northeastern Finland","authors":"P. Nikkola, I. Mänttäri, O. T. Rämö","doi":"10.17741/BGSF/89.1.002","DOIUrl":null,"url":null,"abstract":"U–Pb zircon single grain dating using the LA-MC-ICP-MS technique was utilized to determine the age of the host rocks of the Juomasuo Au–Co–Cu deposit located in the late Archean Kuusamo supracrustal belt. Even though the dated samples have diverse geochemical signatures that imply felsic volcanic and sedimentary precursors, the U–Pb data revealed heterogeneous detrital zircon populations for all samples. The host rocks are thus considered to belong to reworked sedimentary/volcano-sedimentary sequences. The maximun depositional ages of the samples fall in the 2.75–2.65 Ga age window, and no Paleoproterozoic ages were recovered in the examined zircon grains (151 analytical spots in total). In addition, a younger population (2.65–2.60 Ga) of internally featureless, BSE-pale/CL-dark zircon and zircon domains, was found in the mineralized sequences. These homogenized zircon grains resemble zircon formed in postmagmatic solid–state processes, in which zircon is recrystallized in metamorphic– hydrothermal conditions. This metamorphic-hydrothermal event most probably occurred in the original provenance area of the metasedimentary rocks.","PeriodicalId":55302,"journal":{"name":"Bulletin of the Geological Society of Finland","volume":null,"pages":null},"PeriodicalIF":1.3000,"publicationDate":"2017-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin of the Geological Society of Finland","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.17741/BGSF/89.1.002","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOLOGY","Score":null,"Total":0}
引用次数: 0

Abstract

U–Pb zircon single grain dating using the LA-MC-ICP-MS technique was utilized to determine the age of the host rocks of the Juomasuo Au–Co–Cu deposit located in the late Archean Kuusamo supracrustal belt. Even though the dated samples have diverse geochemical signatures that imply felsic volcanic and sedimentary precursors, the U–Pb data revealed heterogeneous detrital zircon populations for all samples. The host rocks are thus considered to belong to reworked sedimentary/volcano-sedimentary sequences. The maximun depositional ages of the samples fall in the 2.75–2.65 Ga age window, and no Paleoproterozoic ages were recovered in the examined zircon grains (151 analytical spots in total). In addition, a younger population (2.65–2.60 Ga) of internally featureless, BSE-pale/CL-dark zircon and zircon domains, was found in the mineralized sequences. These homogenized zircon grains resemble zircon formed in postmagmatic solid–state processes, in which zircon is recrystallized in metamorphic– hydrothermal conditions. This metamorphic-hydrothermal event most probably occurred in the original provenance area of the metasedimentary rocks.
芬兰东北部Juomasuo Au-Co-Cu矿床寄主岩U-Pb锆石年龄
采用LA-MC-ICP-MS技术对古萨莫上地壳带晚太古宙巨马索金钴铜矿床主岩年龄进行了U-Pb锆石单粒测年。尽管测年样品具有不同的地球化学特征,暗示了长英质火山和沉积前体,但U-Pb数据显示所有样品的碎屑锆石种群均不均匀。因此,寄主岩被认为属于改造后的沉积/火山-沉积层序。样品的最大沉积年龄落在2.75 ~ 2.65 Ga的年龄窗内,所测锆石颗粒(共151个分析点)未测得古元古代年龄。此外,在矿化层序中发现了较年轻(2.65 ~ 2.60 Ga)的内部无特征的BSE-pale/CL-dark锆石和锆石域。这些均质锆石颗粒类似于变质热液条件下锆石再结晶形成的岩浆后固态过程。此次变质热液事件极有可能发生在变质沉积岩原物源区。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
CiteScore
1.30
自引率
0.00%
发文量
5
审稿时长
>12 weeks
期刊介绍: Bulletin of the Geological Society of Finland (BGSF) publishes research articles and short communications in all branches of geosciences. Contributions from outside Finland are welcome, provided that they contain material relevant to Finnish geology or are of general interest.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信