Tab. 1+2: Representative electron-microprobe analyses of minerals from Du Toit Nunataks
An example of cordierite-bearing gneiss that is part of a high-grade gneiss-migmatite sequence is described from the Hatch Plain in the Read Mountains of the Shackleton Range, Antarctica, for the first time. The cordierite-bearing rocks constitute the more melanosomic portions of the metatectic and...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.763845 2023-05-15T13:55:14+02:00 Tab. 1+2: Representative electron-microprobe analyses of minerals from Du Toit Nunataks Schubert, Wolfgang Olesch, Martin LATITUDE: -80.766700 * LONGITUDE: -25.750000 2011-08-13 text/tab-separated-values, 321 data points https://doi.pangaea.de/10.1594/PANGAEA.763845 https://doi.org/10.1594/PANGAEA.763845 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.763845 https://doi.org/10.1594/PANGAEA.763845 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Schubert, Wolfgang; Olesch, Martin (1995): Cordierite in the Shackleton Range, Antarctica: first recorded occurrence. Polarforschung, 63(2/3), 153-164, hdl:10013/epic.29719.d001 - Aluminium Aluminium (IV) Aluminium (VI) Aluminium oxide Barium Barium oxide Calcium Calcium oxide Chromium Chromium(III) oxide Comment Du Toi Nunataks Read Group Shackleton Range Antarctia Geological sample GEOS Hatch_Plain Iron 2+ Iron 3+ Iron oxide FeO Magnesium Magnesium oxide Manganese Manganese oxide Microprobe Mineral name Number of oxygens Potassium Potassium oxide Sample code/label Silicon Silicon dioxide Sodium Sodium oxide Sum Titanium Titanium dioxide Dataset 2011 ftpangaea https://doi.org/10.1594/PANGAEA.763845 2023-01-20T08:52:36Z An example of cordierite-bearing gneiss that is part of a high-grade gneiss-migmatite sequence is described from the Hatch Plain in the Read Mountains of the Shackleton Range, Antarctica, for the first time. The cordierite-bearing rocks constitute the more melanosomic portions of the metatectic and migmatitic rocks that are associated with relict granulite facies rocks such as enderbitic granulite and enderbitic garnet granulite. The predominant mineral assemblage in the cordierite-bearing rocks is chemically homogeneous cordierite (XMg 0.61) and biotite (XMg 0.47), strongly zoned garnet (XMg 0.18-0.11), sillimanite, K-feldspar (Or81-94Ab5-18An0.6), plagioclase (An28), and quartz. Inclusions of sillimanite and biotite relics in both garnet and cordierite indicate that garnet and cordierite were produced by the coupled, discontinuous reaction biotite + sillimanite + quartz = cordierite + garnet + K-feldspar + H2O. Various garnet-biotite and garnet-cordierite geothermometers and sillimanite-quartz-plagioclase-garnet-cordierite geobarometers yield a continuous clockwise path in the P-T diagram. The P-T conditions for equilibrium between garnet core and cordierite and between garnet core and biotite during peak metamorphism and migmatization were estimated to be 690 °C at 5-6 kb. This was followed by cooling and unloading with continuously changing conditions down to 515 °C at 2-3 kb. This low-pressure re-equilibration correlates with the pressure conditions evaluated by SCHULZE (1989) for the widespread granitic gneisses of the Read Group in the Shackleton Range. The associated relict enderbitic granulites representing low-pressure type granulite (8 kb; 790 °C) are comparable to similar low-pressure granulites from the East Antarctic craton. They were either formed by under-accretion processes after collision (WELLS 1979, p. 217) or they are a product of remetamorphism at P-T conditions intermediate between granulite and amphibolite facies. A model of a multiple imbrication zone with crustal thickening (CUTHBERT et ... Dataset Antarc* Antarctic Antarctica Polarforschung PANGAEA - Data Publisher for Earth & Environmental Science Antarctic Du Toit Nunataks ENVELOPE(-25.831,-25.831,-80.719,-80.719) Hatch Plain ENVELOPE(-25.673,-25.673,-80.731,-80.731) Read Mountains ENVELOPE(-24.323,-24.323,-80.672,-80.672) Shackleton Shackleton Range ENVELOPE(-26.000,-26.000,-80.833,-80.833) ENVELOPE(-25.750000,-25.750000,-80.766700,-80.766700) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
- Aluminium Aluminium (IV) Aluminium (VI) Aluminium oxide Barium Barium oxide Calcium Calcium oxide Chromium Chromium(III) oxide Comment Du Toi Nunataks Read Group Shackleton Range Antarctia Geological sample GEOS Hatch_Plain Iron 2+ Iron 3+ Iron oxide FeO Magnesium Magnesium oxide Manganese Manganese oxide Microprobe Mineral name Number of oxygens Potassium Potassium oxide Sample code/label Silicon Silicon dioxide Sodium Sodium oxide Sum Titanium Titanium dioxide |
spellingShingle |
- Aluminium Aluminium (IV) Aluminium (VI) Aluminium oxide Barium Barium oxide Calcium Calcium oxide Chromium Chromium(III) oxide Comment Du Toi Nunataks Read Group Shackleton Range Antarctia Geological sample GEOS Hatch_Plain Iron 2+ Iron 3+ Iron oxide FeO Magnesium Magnesium oxide Manganese Manganese oxide Microprobe Mineral name Number of oxygens Potassium Potassium oxide Sample code/label Silicon Silicon dioxide Sodium Sodium oxide Sum Titanium Titanium dioxide Schubert, Wolfgang Olesch, Martin Tab. 1+2: Representative electron-microprobe analyses of minerals from Du Toit Nunataks |
topic_facet |
- Aluminium Aluminium (IV) Aluminium (VI) Aluminium oxide Barium Barium oxide Calcium Calcium oxide Chromium Chromium(III) oxide Comment Du Toi Nunataks Read Group Shackleton Range Antarctia Geological sample GEOS Hatch_Plain Iron 2+ Iron 3+ Iron oxide FeO Magnesium Magnesium oxide Manganese Manganese oxide Microprobe Mineral name Number of oxygens Potassium Potassium oxide Sample code/label Silicon Silicon dioxide Sodium Sodium oxide Sum Titanium Titanium dioxide |
description |
An example of cordierite-bearing gneiss that is part of a high-grade gneiss-migmatite sequence is described from the Hatch Plain in the Read Mountains of the Shackleton Range, Antarctica, for the first time. The cordierite-bearing rocks constitute the more melanosomic portions of the metatectic and migmatitic rocks that are associated with relict granulite facies rocks such as enderbitic granulite and enderbitic garnet granulite. The predominant mineral assemblage in the cordierite-bearing rocks is chemically homogeneous cordierite (XMg 0.61) and biotite (XMg 0.47), strongly zoned garnet (XMg 0.18-0.11), sillimanite, K-feldspar (Or81-94Ab5-18An0.6), plagioclase (An28), and quartz. Inclusions of sillimanite and biotite relics in both garnet and cordierite indicate that garnet and cordierite were produced by the coupled, discontinuous reaction biotite + sillimanite + quartz = cordierite + garnet + K-feldspar + H2O. Various garnet-biotite and garnet-cordierite geothermometers and sillimanite-quartz-plagioclase-garnet-cordierite geobarometers yield a continuous clockwise path in the P-T diagram. The P-T conditions for equilibrium between garnet core and cordierite and between garnet core and biotite during peak metamorphism and migmatization were estimated to be 690 °C at 5-6 kb. This was followed by cooling and unloading with continuously changing conditions down to 515 °C at 2-3 kb. This low-pressure re-equilibration correlates with the pressure conditions evaluated by SCHULZE (1989) for the widespread granitic gneisses of the Read Group in the Shackleton Range. The associated relict enderbitic granulites representing low-pressure type granulite (8 kb; 790 °C) are comparable to similar low-pressure granulites from the East Antarctic craton. They were either formed by under-accretion processes after collision (WELLS 1979, p. 217) or they are a product of remetamorphism at P-T conditions intermediate between granulite and amphibolite facies. A model of a multiple imbrication zone with crustal thickening (CUTHBERT et ... |
format |
Dataset |
author |
Schubert, Wolfgang Olesch, Martin |
author_facet |
Schubert, Wolfgang Olesch, Martin |
author_sort |
Schubert, Wolfgang |
title |
Tab. 1+2: Representative electron-microprobe analyses of minerals from Du Toit Nunataks |
title_short |
Tab. 1+2: Representative electron-microprobe analyses of minerals from Du Toit Nunataks |
title_full |
Tab. 1+2: Representative electron-microprobe analyses of minerals from Du Toit Nunataks |
title_fullStr |
Tab. 1+2: Representative electron-microprobe analyses of minerals from Du Toit Nunataks |
title_full_unstemmed |
Tab. 1+2: Representative electron-microprobe analyses of minerals from Du Toit Nunataks |
title_sort |
tab. 1+2: representative electron-microprobe analyses of minerals from du toit nunataks |
publisher |
PANGAEA |
publishDate |
2011 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.763845 https://doi.org/10.1594/PANGAEA.763845 |
op_coverage |
LATITUDE: -80.766700 * LONGITUDE: -25.750000 |
long_lat |
ENVELOPE(-25.831,-25.831,-80.719,-80.719) ENVELOPE(-25.673,-25.673,-80.731,-80.731) ENVELOPE(-24.323,-24.323,-80.672,-80.672) ENVELOPE(-26.000,-26.000,-80.833,-80.833) ENVELOPE(-25.750000,-25.750000,-80.766700,-80.766700) |
geographic |
Antarctic Du Toit Nunataks Hatch Plain Read Mountains Shackleton Shackleton Range |
geographic_facet |
Antarctic Du Toit Nunataks Hatch Plain Read Mountains Shackleton Shackleton Range |
genre |
Antarc* Antarctic Antarctica Polarforschung |
genre_facet |
Antarc* Antarctic Antarctica Polarforschung |
op_source |
Supplement to: Schubert, Wolfgang; Olesch, Martin (1995): Cordierite in the Shackleton Range, Antarctica: first recorded occurrence. Polarforschung, 63(2/3), 153-164, hdl:10013/epic.29719.d001 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.763845 https://doi.org/10.1594/PANGAEA.763845 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/PANGAEA.763845 |
_version_ |
1766261549516718080 |