Osumilite and a spinel + quartz association in garnet-sillimanite gneiss from Rundvågshetta, Lützow-Holm Complex, East Antarctica

Toshisuke Kawasaki, Nobuhiko Nakano, Yasuhito Osanai

研究成果: ジャーナルへの寄稿記事

31 引用 (Scopus)

抄録

This is the first report of osumilite occurring as fine isolated inclusions within garnet porphyroblasts, as observed in garnet-sillimanite gneiss from Rundvågshetta, Lützow-Holm Complex, East Antarctica. The osumilite is characterized by high Si content (10.60 and 10.95 atoms based on 30 oxygens per formula unit), low Al content (2.99 and 3.82), a high content of M site-occupying cations (2.51 and 3.03), and high XMg values (about 0.81). We also report a spinel+quartz association found as inclusions within garnet porphyroblasts. Spinel grains, which are in direct contact with quartz and are spatially associated with sillimanite, show extremely high Zn contents (XZn Spl=0.33-0.46) and high XMg values (0.45-0.54). The garnet is rimmed by sillimanite, K-feldspar, plagioclase, and quartz. Biotite and cordierite are found only as inclusions within garnet porphyroblasts, where biotite coexists with spinel-quartz or with rutile. Porphyroblastic garnet contains rutile needles and has low XMg values (about 0.36). The sillimanite contains a high Fe content (about 1.2wt.% Fe2O3).The occurrence of osumilite and spinel + quartz indicates a clockwise pressure-temperature path of ultrahigh-temperature metamorphism, involving the following events: (1) the Rundvågshetta granulites suffered prograde metamorphism within the kyanite and sapphirine. + quartz fields; (2) subsequent retrograde metamorphism, involving near-isothermal decompression, occurred in the orthopyroxene + sillimanite + quartz field; (3) the granulites passed through the garnet + cordierite + sillimanite + quartz field during decreasing temperature; (4) the granulites entered the osumilite stability field at around 8. kbar and 950 °C; and (5) the granulites retain a final record of retrograde metamorphism within the biotite + sillimanite + K-feldspar and quartz field at 6.1. kbar and about 830 °C.

元の言語英語
ページ(範囲)430-445
ページ数16
ジャーナルGondwana Research
19
発行部数2
DOI
出版物ステータス出版済み - 3 1 2011

Fingerprint

sillimanite
spinel
gneiss
garnet
quartz
porphyroblast
biotite
retrograde metamorphism
cordierite
rutile
feldspar
ultrahigh temperature metamorphism
sapphirine
Antarctica
prograde metamorphism
kyanite
decompression
orthopyroxene
plagioclase
cation

All Science Journal Classification (ASJC) codes

  • Geology

これを引用

Osumilite and a spinel + quartz association in garnet-sillimanite gneiss from Rundvågshetta, Lützow-Holm Complex, East Antarctica. / Kawasaki, Toshisuke; Nakano, Nobuhiko; Osanai, Yasuhito.

:: Gondwana Research, 巻 19, 番号 2, 01.03.2011, p. 430-445.

研究成果: ジャーナルへの寄稿記事

@article{21812547e3c84956b44ec47d5a660801,
title = "Osumilite and a spinel + quartz association in garnet-sillimanite gneiss from Rundv{\aa}gshetta, L{\"u}tzow-Holm Complex, East Antarctica",
abstract = "This is the first report of osumilite occurring as fine isolated inclusions within garnet porphyroblasts, as observed in garnet-sillimanite gneiss from Rundv{\aa}gshetta, L{\"u}tzow-Holm Complex, East Antarctica. The osumilite is characterized by high Si content (10.60 and 10.95 atoms based on 30 oxygens per formula unit), low Al content (2.99 and 3.82), a high content of M site-occupying cations (2.51 and 3.03), and high XMg values (about 0.81). We also report a spinel+quartz association found as inclusions within garnet porphyroblasts. Spinel grains, which are in direct contact with quartz and are spatially associated with sillimanite, show extremely high Zn contents (XZn Spl=0.33-0.46) and high XMg values (0.45-0.54). The garnet is rimmed by sillimanite, K-feldspar, plagioclase, and quartz. Biotite and cordierite are found only as inclusions within garnet porphyroblasts, where biotite coexists with spinel-quartz or with rutile. Porphyroblastic garnet contains rutile needles and has low XMg values (about 0.36). The sillimanite contains a high Fe content (about 1.2wt.{\%} Fe2O3).The occurrence of osumilite and spinel + quartz indicates a clockwise pressure-temperature path of ultrahigh-temperature metamorphism, involving the following events: (1) the Rundv{\aa}gshetta granulites suffered prograde metamorphism within the kyanite and sapphirine. + quartz fields; (2) subsequent retrograde metamorphism, involving near-isothermal decompression, occurred in the orthopyroxene + sillimanite + quartz field; (3) the granulites passed through the garnet + cordierite + sillimanite + quartz field during decreasing temperature; (4) the granulites entered the osumilite stability field at around 8. kbar and 950 °C; and (5) the granulites retain a final record of retrograde metamorphism within the biotite + sillimanite + K-feldspar and quartz field at 6.1. kbar and about 830 °C.",
author = "Toshisuke Kawasaki and Nobuhiko Nakano and Yasuhito Osanai",
year = "2011",
month = "3",
day = "1",
doi = "10.1016/j.gr.2010.07.008",
language = "English",
volume = "19",
pages = "430--445",
journal = "Gondwana Research",
issn = "1342-937X",
publisher = "Elsevier Inc.",
number = "2",

}

TY - JOUR

T1 - Osumilite and a spinel + quartz association in garnet-sillimanite gneiss from Rundvågshetta, Lützow-Holm Complex, East Antarctica

AU - Kawasaki, Toshisuke

AU - Nakano, Nobuhiko

AU - Osanai, Yasuhito

PY - 2011/3/1

Y1 - 2011/3/1

N2 - This is the first report of osumilite occurring as fine isolated inclusions within garnet porphyroblasts, as observed in garnet-sillimanite gneiss from Rundvågshetta, Lützow-Holm Complex, East Antarctica. The osumilite is characterized by high Si content (10.60 and 10.95 atoms based on 30 oxygens per formula unit), low Al content (2.99 and 3.82), a high content of M site-occupying cations (2.51 and 3.03), and high XMg values (about 0.81). We also report a spinel+quartz association found as inclusions within garnet porphyroblasts. Spinel grains, which are in direct contact with quartz and are spatially associated with sillimanite, show extremely high Zn contents (XZn Spl=0.33-0.46) and high XMg values (0.45-0.54). The garnet is rimmed by sillimanite, K-feldspar, plagioclase, and quartz. Biotite and cordierite are found only as inclusions within garnet porphyroblasts, where biotite coexists with spinel-quartz or with rutile. Porphyroblastic garnet contains rutile needles and has low XMg values (about 0.36). The sillimanite contains a high Fe content (about 1.2wt.% Fe2O3).The occurrence of osumilite and spinel + quartz indicates a clockwise pressure-temperature path of ultrahigh-temperature metamorphism, involving the following events: (1) the Rundvågshetta granulites suffered prograde metamorphism within the kyanite and sapphirine. + quartz fields; (2) subsequent retrograde metamorphism, involving near-isothermal decompression, occurred in the orthopyroxene + sillimanite + quartz field; (3) the granulites passed through the garnet + cordierite + sillimanite + quartz field during decreasing temperature; (4) the granulites entered the osumilite stability field at around 8. kbar and 950 °C; and (5) the granulites retain a final record of retrograde metamorphism within the biotite + sillimanite + K-feldspar and quartz field at 6.1. kbar and about 830 °C.

AB - This is the first report of osumilite occurring as fine isolated inclusions within garnet porphyroblasts, as observed in garnet-sillimanite gneiss from Rundvågshetta, Lützow-Holm Complex, East Antarctica. The osumilite is characterized by high Si content (10.60 and 10.95 atoms based on 30 oxygens per formula unit), low Al content (2.99 and 3.82), a high content of M site-occupying cations (2.51 and 3.03), and high XMg values (about 0.81). We also report a spinel+quartz association found as inclusions within garnet porphyroblasts. Spinel grains, which are in direct contact with quartz and are spatially associated with sillimanite, show extremely high Zn contents (XZn Spl=0.33-0.46) and high XMg values (0.45-0.54). The garnet is rimmed by sillimanite, K-feldspar, plagioclase, and quartz. Biotite and cordierite are found only as inclusions within garnet porphyroblasts, where biotite coexists with spinel-quartz or with rutile. Porphyroblastic garnet contains rutile needles and has low XMg values (about 0.36). The sillimanite contains a high Fe content (about 1.2wt.% Fe2O3).The occurrence of osumilite and spinel + quartz indicates a clockwise pressure-temperature path of ultrahigh-temperature metamorphism, involving the following events: (1) the Rundvågshetta granulites suffered prograde metamorphism within the kyanite and sapphirine. + quartz fields; (2) subsequent retrograde metamorphism, involving near-isothermal decompression, occurred in the orthopyroxene + sillimanite + quartz field; (3) the granulites passed through the garnet + cordierite + sillimanite + quartz field during decreasing temperature; (4) the granulites entered the osumilite stability field at around 8. kbar and 950 °C; and (5) the granulites retain a final record of retrograde metamorphism within the biotite + sillimanite + K-feldspar and quartz field at 6.1. kbar and about 830 °C.

UR - http://www.scopus.com/inward/record.url?scp=78751704193&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=78751704193&partnerID=8YFLogxK

U2 - 10.1016/j.gr.2010.07.008

DO - 10.1016/j.gr.2010.07.008

M3 - Article

AN - SCOPUS:78751704193

VL - 19

SP - 430

EP - 445

JO - Gondwana Research

JF - Gondwana Research

SN - 1342-937X

IS - 2

ER -