Metamorphism and partial melting at UHP conditions revealed by microdiamonds and melt inclusions in metapelitic gneiss from Heia, Arctic Caledonides, Norway

地质学 片麻岩 变质作用 地球化学 部分熔融 熔融包裹体 北极的 岩石学 变质岩 结壳 地幔(地质学) 海洋学
作者
Marian Janák,Alessia Borghini,Iwona Klonowska,Kenta Yoshida,Viera Dujnič,Sergii Kurylo,Nikolaus Froitzheim,Igor Petrík,Jarosław Majka
出处
期刊:Journal of Petrology [Oxford University Press]
卷期号:65 (11) 被引量:1
标识
DOI:10.1093/petrology/egae114
摘要

Abstract Primary multiphase inclusions trapped in host minerals such as garnet may provide important information about the nature of fluids and melts and their crystallization products. The occurrence of melt and fluid inclusions in the same cluster suggests primary fluid-melt immiscibility during partial melting. Here we report the coexistence of diamond-bearing fluid inclusions with melt inclusions in metasedimentary UHP rocks of the Nordmannvik Nappe at Heia, in the Arctic Caledonides of Norway. Multiphase fluid inclusions (Type I) and primary melt inclusions (Type II) have been identified in garnet and studied in detail. Microscopic observations, Raman spectroscopy, FIB-SEM, and EDS analysis show that microdiamonds occur in situ, in multiphase fluid inclusions (Type I) distributed in clusters in the garnet mantle. The Raman spectra suggest partial transformation of diamond to disordered sp2-bonded carbon structure. Along with diamond, Type I inclusions contain (i) rutile and apatite as trapped solid phases, (ii) carbonates (magnesite-siderite) and Al-phyllosilicates (white mica, phlogopite, pyrophyllite) as daughter or step-daughter minerals, and (iii) CO2 as a residual fluid phase. Former melt inclusions (Type II) occur in the same microstructural position in the host garnet. They contain muscovite, paragonite, phlogopite, K-feldspar, plagioclase, albite and quartz as solid phases crystallized from a melt, and kyanite as accidentally trapped mineral. The occurrence of melt inclusions in the inner part of garnets thus suggests that garnet was growing in the presence of melt. Garnet is nearly homogeneous with respect to major elements Mg, Fe, Ca and Mn, expressed by pyrope (0.18–0.22 XPrp), grossular (0.09–0.12 XGrs), almandine (0.67–0.70 XAlm) and spessartine (0.01–0.03 XSps) except local Ca enrichment in the rim. Trace elements show decreasing HREE and Y patterns from the core to the mantle suggesting garnet growth according to the Rayleigh fractionation model. Phosphorus shows an elevated content in the core and mantle. A positive correlation between P and Na indicates a coupled NaPM2+−1Si−1 substitution in garnet. Minimum P–T conditions of 3.7 to 3.8 GPa and 840°C to 870°C for the peak metamorphic stage were estimated from garnet composition (XPrp = 0.22), zirconium-in rutile thermometry of rutile inclusions in garnet (747–977 ppm of Zr) and diamond/graphite stability boundary. Partial melting on a prograde P–T path was controlled by the decomposition of phengite in the presence of C–O–H fluid, producing peritectic garnet ± kyanite along with melt, in the diamond stability field. The coexistence of diamond-bearing multiphase fluid inclusions with melt inclusions suggests primary fluid-melt immiscibility at UHP conditions. During exhumation, the rock underwent decompression and second partial melting, leading to enrichment in Ca, Y, Cr and Sc of garnet rims. Microdiamonds found in metasedimentary crustal rocks at Heia provide new evidence of UHP metamorphism in the Nordmannvik Nappe of the Arctic Caledonides. The results favour a correlation with the pre-Scandian subduction and arc–continent collision events of the Caledonian Orogeny.
最长约 10秒,即可获得该文献文件

科研通智能强力驱动
Strongly Powered by AbleSci AI
更新
PDF的下载单位、IP信息已删除 (2025-6-4)

科研通是完全免费的文献互助平台,具备全网最快的应助速度,最高的求助完成率。 对每一个文献求助,科研通都将尽心尽力,给求助人一个满意的交代。
实时播报
量子星尘发布了新的文献求助10
1秒前
Minicoper发布了新的文献求助10
1秒前
背书强完成签到 ,获得积分10
2秒前
淡然以柳完成签到 ,获得积分10
4秒前
dolabmu完成签到 ,获得积分10
7秒前
崔崔完成签到 ,获得积分10
11秒前
SYLH应助xcxc采纳,获得10
12秒前
wp4455777完成签到,获得积分10
13秒前
十一完成签到,获得积分10
13秒前
ru完成签到 ,获得积分10
15秒前
慧木完成签到 ,获得积分10
15秒前
WW完成签到 ,获得积分10
16秒前
小高同学完成签到,获得积分10
17秒前
轻轻1完成签到,获得积分10
20秒前
21秒前
大橙子发布了新的文献求助10
25秒前
iuhgnor完成签到,获得积分10
28秒前
可夫司机完成签到 ,获得积分10
31秒前
yang完成签到,获得积分10
33秒前
一1完成签到 ,获得积分10
35秒前
jiaolulu完成签到,获得积分10
35秒前
量子星尘发布了新的文献求助10
37秒前
爆米花应助LiZhao采纳,获得10
37秒前
轻轻完成签到,获得积分10
40秒前
Orange应助jiaolulu采纳,获得10
40秒前
xcxc完成签到,获得积分10
42秒前
water应助科研通管家采纳,获得50
42秒前
42秒前
默存完成签到,获得积分10
45秒前
风中的金鱼完成签到 ,获得积分10
47秒前
橙汁完成签到,获得积分10
48秒前
普鲁卡因发布了新的文献求助10
51秒前
cora完成签到 ,获得积分10
57秒前
徐伟康完成签到 ,获得积分10
57秒前
Minicoper完成签到,获得积分10
1分钟前
科研通AI5应助普鲁卡因采纳,获得10
1分钟前
111完成签到 ,获得积分10
1分钟前
奥特曼完成签到 ,获得积分10
1分钟前
苏苏完成签到,获得积分10
1分钟前
大橙子完成签到,获得积分10
1分钟前
高分求助中
【提示信息,请勿应助】关于scihub 10000
Les Mantodea de Guyane: Insecta, Polyneoptera [The Mantids of French Guiana] 3000
徐淮辽南地区新元古代叠层石及生物地层 3000
The Mother of All Tableaux: Order, Equivalence, and Geometry in the Large-scale Structure of Optimality Theory 3000
Handbook of Industrial Diamonds.Vol2 1100
Global Eyelash Assessment scale (GEA) 1000
Picture Books with Same-sex Parented Families: Unintentional Censorship 550
热门求助领域 (近24小时)
化学 材料科学 医学 生物 工程类 有机化学 生物化学 物理 内科学 纳米技术 计算机科学 化学工程 复合材料 遗传学 基因 物理化学 催化作用 冶金 细胞生物学 免疫学
热门帖子
关注 科研通微信公众号,转发送积分 4038128
求助须知:如何正确求助?哪些是违规求助? 3575831
关于积分的说明 11373827
捐赠科研通 3305610
什么是DOI,文献DOI怎么找? 1819255
邀请新用户注册赠送积分活动 892655
科研通“疑难数据库(出版商)”最低求助积分说明 815022