Stable coexistence of grandiderite and kornerupine during medium pressure granulite facies metamorphism
<jats:title>Abstract</jats:title><jats:p>Petrological and mineral chemical data are presented for two new occurrences of co-existing borosilicate minerals in the Larsemann Hills, East Antarctica. The assemblages contain kornerupine and the rare borosilicate, grandidierite (Mg,Fe)A1...
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Mineralogical Society
1995
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Online Access: | http://hdl.handle.net/2440/13819 https://doi.org/10.1180/minmag.1995.059.395.16 |
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ftunivadelaidedl:oai:digital.library.adelaide.edu.au:2440/13819 2023-12-17T10:21:49+01:00 Stable coexistence of grandiderite and kornerupine during medium pressure granulite facies metamorphism Carson, C. Hand, M. Dirks, P. 1995 http://hdl.handle.net/2440/13819 https://doi.org/10.1180/minmag.1995.059.395.16 en eng Mineralogical Society Mineralogical Magazine, 1995; 59(395):327-339 0026-461X 1471-8022 http://hdl.handle.net/2440/13819 doi:10.1180/minmag.1995.059.395.16 Hand, M. [0000-0003-3743-9706] http://dx.doi.org/10.1180/minmag.1995.059.395.16 Journal article 1995 ftunivadelaidedl https://doi.org/10.1180/minmag.1995.059.395.16 2023-11-20T23:34:15Z <jats:title>Abstract</jats:title><jats:p>Petrological and mineral chemical data are presented for two new occurrences of co-existing borosilicate minerals in the Larsemann Hills, East Antarctica. The assemblages contain kornerupine and the rare borosilicate, grandidierite (Mg,Fe)A1<jats:sub>3</jats:sub>BSiO<jats:sub>9</jats:sub>. Two distinct associations occur: (1) At McCarthy Point, 1–10 mm thick tourmaline-kornerupine-grandidierite layers are hosted within quartzofeldspathic gneiss; and (2) Seal Cove, where coexisting kornerupine and grandidierite occur within coarse-grained, metamorphic segregations with Mg-rich cores of cordierite-garnet-spinel-biotite-ilmenite and variably developed plagioclase halos. The segregations are hosted within biotite-bearing, plagio-feldspathic gneiss. Textural relationships from these localities indicate the stability of co-existing kornerupine and grandidierite.</jats:p><jats:p>The grandidierite- and kornerupine-bearing segregations from Seal Cove largely postdate structures developed during a crustal thickening event (D<jats:sub>2</jats:sub>) which was coeval with peak metamorphism. At McCarthy Point, grandidierite, kornerupine and late-tourmaline growth predates, or is synchronous, with F<jats:sub>3</jats:sub> fold structures developed during a extensive granulite grade, normal shearing event (D<jats:sub>3</jats:sub>) which occurred prior to, and synchronous with, near-isothermal decompression. Average pressure calculations on assemblages that coexist with the borosilicates at Seal Cove, indicate the prevailing conditions were 5.2–5.5 kbar at ∼ 750°C for formation of the grandidierite-kornerupine assemblage.</jats:p> Article in Journal/Newspaper Antarc* Antarctica East Antarctica The University of Adelaide: Digital Library East Antarctica Larsemann Hills ENVELOPE(76.217,76.217,-69.400,-69.400) McCarthy ENVELOPE(66.543,66.543,-70.404,-70.404) McCarthy Point ENVELOPE(76.053,76.053,-69.464,-69.464) Seal Cove ENVELOPE(76.400,76.400,-69.385,-69.385) Mineralogical Magazine 59 395 327 339 |
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Open Polar |
collection |
The University of Adelaide: Digital Library |
op_collection_id |
ftunivadelaidedl |
language |
English |
description |
<jats:title>Abstract</jats:title><jats:p>Petrological and mineral chemical data are presented for two new occurrences of co-existing borosilicate minerals in the Larsemann Hills, East Antarctica. The assemblages contain kornerupine and the rare borosilicate, grandidierite (Mg,Fe)A1<jats:sub>3</jats:sub>BSiO<jats:sub>9</jats:sub>. Two distinct associations occur: (1) At McCarthy Point, 1–10 mm thick tourmaline-kornerupine-grandidierite layers are hosted within quartzofeldspathic gneiss; and (2) Seal Cove, where coexisting kornerupine and grandidierite occur within coarse-grained, metamorphic segregations with Mg-rich cores of cordierite-garnet-spinel-biotite-ilmenite and variably developed plagioclase halos. The segregations are hosted within biotite-bearing, plagio-feldspathic gneiss. Textural relationships from these localities indicate the stability of co-existing kornerupine and grandidierite.</jats:p><jats:p>The grandidierite- and kornerupine-bearing segregations from Seal Cove largely postdate structures developed during a crustal thickening event (D<jats:sub>2</jats:sub>) which was coeval with peak metamorphism. At McCarthy Point, grandidierite, kornerupine and late-tourmaline growth predates, or is synchronous, with F<jats:sub>3</jats:sub> fold structures developed during a extensive granulite grade, normal shearing event (D<jats:sub>3</jats:sub>) which occurred prior to, and synchronous with, near-isothermal decompression. Average pressure calculations on assemblages that coexist with the borosilicates at Seal Cove, indicate the prevailing conditions were 5.2–5.5 kbar at ∼ 750°C for formation of the grandidierite-kornerupine assemblage.</jats:p> |
format |
Article in Journal/Newspaper |
author |
Carson, C. Hand, M. Dirks, P. |
spellingShingle |
Carson, C. Hand, M. Dirks, P. Stable coexistence of grandiderite and kornerupine during medium pressure granulite facies metamorphism |
author_facet |
Carson, C. Hand, M. Dirks, P. |
author_sort |
Carson, C. |
title |
Stable coexistence of grandiderite and kornerupine during medium pressure granulite facies metamorphism |
title_short |
Stable coexistence of grandiderite and kornerupine during medium pressure granulite facies metamorphism |
title_full |
Stable coexistence of grandiderite and kornerupine during medium pressure granulite facies metamorphism |
title_fullStr |
Stable coexistence of grandiderite and kornerupine during medium pressure granulite facies metamorphism |
title_full_unstemmed |
Stable coexistence of grandiderite and kornerupine during medium pressure granulite facies metamorphism |
title_sort |
stable coexistence of grandiderite and kornerupine during medium pressure granulite facies metamorphism |
publisher |
Mineralogical Society |
publishDate |
1995 |
url |
http://hdl.handle.net/2440/13819 https://doi.org/10.1180/minmag.1995.059.395.16 |
long_lat |
ENVELOPE(76.217,76.217,-69.400,-69.400) ENVELOPE(66.543,66.543,-70.404,-70.404) ENVELOPE(76.053,76.053,-69.464,-69.464) ENVELOPE(76.400,76.400,-69.385,-69.385) |
geographic |
East Antarctica Larsemann Hills McCarthy McCarthy Point Seal Cove |
geographic_facet |
East Antarctica Larsemann Hills McCarthy McCarthy Point Seal Cove |
genre |
Antarc* Antarctica East Antarctica |
genre_facet |
Antarc* Antarctica East Antarctica |
op_source |
http://dx.doi.org/10.1180/minmag.1995.059.395.16 |
op_relation |
Mineralogical Magazine, 1995; 59(395):327-339 0026-461X 1471-8022 http://hdl.handle.net/2440/13819 doi:10.1180/minmag.1995.059.395.16 Hand, M. [0000-0003-3743-9706] |
op_doi |
https://doi.org/10.1180/minmag.1995.059.395.16 |
container_title |
Mineralogical Magazine |
container_volume |
59 |
container_issue |
395 |
container_start_page |
327 |
op_container_end_page |
339 |
_version_ |
1785539301423972352 |