Contrasting P-T-t paths for neoproterozoic metamorphism in MacRobertson and Kemp lands, east Antarctica
The definitive version is available at onlinelibrary.wiley.com Mineral equilibria modelling and electron microprobe chemical dating of monazite in granulite facies metapelitic assemblages from the MacRobertson Land coastline, Rayner Complex, east Antarctica, are consistent with an ‘anticlockwise’ Ne...
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Blackwell Publishing Ltd
2007
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Online Access: | http://hdl.handle.net/2440/44143 https://doi.org/10.1111/j.1525-1314.2007.00723.x |
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ftunivadelaidedl:oai:digital.library.adelaide.edu.au:2440/44143 2023-12-24T10:11:05+01:00 Contrasting P-T-t paths for neoproterozoic metamorphism in MacRobertson and Kemp lands, east Antarctica Halpin, J. Clarke, G. White, R. Kelsey, D. 2007 http://hdl.handle.net/2440/44143 https://doi.org/10.1111/j.1525-1314.2007.00723.x en eng Blackwell Publishing Ltd Journal of Metamorphic Geology, 2007; 25(6):683-701 0263-4929 1525-1314 http://hdl.handle.net/2440/44143 doi:10.1111/j.1525-1314.2007.00723.x http://dx.doi.org/10.1111/j.1525-1314.2007.00723.x Journal article 2007 ftunivadelaidedl https://doi.org/10.1111/j.1525-1314.2007.00723.x 2023-11-27T23:20:58Z The definitive version is available at onlinelibrary.wiley.com Mineral equilibria modelling and electron microprobe chemical dating of monazite in granulite facies metapelitic assemblages from the MacRobertson Land coastline, Rayner Complex, east Antarctica, are consistent with an ‘anticlockwise’ Neoproterozoic P–T–t path. Metamorphism occurred at c. 990–970 Ma, achieving peak conditions of 850 °C and 5.6–6.2 kbar at Cape Bruce, and 900 °C and 5.4–6.2 kbar at the Forbes Glacier 50 km to the east. These peak metamorphic conditions preceded the emplacement of regionally extensive syntectonic charnockite. High temperature conditions are likely to have been sustained for 80 Myr by lithospheric thinning and repeated pluton emplacement; advection was accompanied by crustal thickening to maximum pressures of 6–7 kbar, followed by near-isobaric cooling. This P–T–t path is distinct from that of rocks in adjacent Kemp Land, 50 km to the west, where a ‘clockwise’ P–T–t path from higher-P conditions at c. 940 Ma may reflect the response of a cratonic margin displaced from the main magma flux. In this scenario, crustal shortening was initially accommodated in younger, fertile crust (MacRobertson Land) involving metasediments and felsic plutons with the transfer of strain to adjacent older crust (Kemp Land) subsequent to charnockite emplacement. J. A. Halpin, G. L. Clarke, R. W. White, D. E. Kelsey Article in Journal/Newspaper Antarc* Antarctica East Antarctica Kemp Land MacRobertson Land The University of Adelaide: Digital Library East Antarctica Forbes ENVELOPE(-66.550,-66.550,-67.783,-67.783) Rayner ENVELOPE(-45.166,-45.166,-60.650,-60.650) Kemp Land ENVELOPE(57.500,57.500,-67.500,-67.500) MacRobertson Land ENVELOPE(65.000,65.000,-70.000,-70.000) Forbes Glacier ENVELOPE(62.350,62.350,-67.633,-67.633) Cape Bruce ENVELOPE(60.795,60.795,-67.427,-67.427) Kelsey ENVELOPE(-22.306,-22.306,-80.448,-80.448) Journal of Metamorphic Geology 25 6 683 701 |
institution |
Open Polar |
collection |
The University of Adelaide: Digital Library |
op_collection_id |
ftunivadelaidedl |
language |
English |
description |
The definitive version is available at onlinelibrary.wiley.com Mineral equilibria modelling and electron microprobe chemical dating of monazite in granulite facies metapelitic assemblages from the MacRobertson Land coastline, Rayner Complex, east Antarctica, are consistent with an ‘anticlockwise’ Neoproterozoic P–T–t path. Metamorphism occurred at c. 990–970 Ma, achieving peak conditions of 850 °C and 5.6–6.2 kbar at Cape Bruce, and 900 °C and 5.4–6.2 kbar at the Forbes Glacier 50 km to the east. These peak metamorphic conditions preceded the emplacement of regionally extensive syntectonic charnockite. High temperature conditions are likely to have been sustained for 80 Myr by lithospheric thinning and repeated pluton emplacement; advection was accompanied by crustal thickening to maximum pressures of 6–7 kbar, followed by near-isobaric cooling. This P–T–t path is distinct from that of rocks in adjacent Kemp Land, 50 km to the west, where a ‘clockwise’ P–T–t path from higher-P conditions at c. 940 Ma may reflect the response of a cratonic margin displaced from the main magma flux. In this scenario, crustal shortening was initially accommodated in younger, fertile crust (MacRobertson Land) involving metasediments and felsic plutons with the transfer of strain to adjacent older crust (Kemp Land) subsequent to charnockite emplacement. J. A. Halpin, G. L. Clarke, R. W. White, D. E. Kelsey |
format |
Article in Journal/Newspaper |
author |
Halpin, J. Clarke, G. White, R. Kelsey, D. |
spellingShingle |
Halpin, J. Clarke, G. White, R. Kelsey, D. Contrasting P-T-t paths for neoproterozoic metamorphism in MacRobertson and Kemp lands, east Antarctica |
author_facet |
Halpin, J. Clarke, G. White, R. Kelsey, D. |
author_sort |
Halpin, J. |
title |
Contrasting P-T-t paths for neoproterozoic metamorphism in MacRobertson and Kemp lands, east Antarctica |
title_short |
Contrasting P-T-t paths for neoproterozoic metamorphism in MacRobertson and Kemp lands, east Antarctica |
title_full |
Contrasting P-T-t paths for neoproterozoic metamorphism in MacRobertson and Kemp lands, east Antarctica |
title_fullStr |
Contrasting P-T-t paths for neoproterozoic metamorphism in MacRobertson and Kemp lands, east Antarctica |
title_full_unstemmed |
Contrasting P-T-t paths for neoproterozoic metamorphism in MacRobertson and Kemp lands, east Antarctica |
title_sort |
contrasting p-t-t paths for neoproterozoic metamorphism in macrobertson and kemp lands, east antarctica |
publisher |
Blackwell Publishing Ltd |
publishDate |
2007 |
url |
http://hdl.handle.net/2440/44143 https://doi.org/10.1111/j.1525-1314.2007.00723.x |
long_lat |
ENVELOPE(-66.550,-66.550,-67.783,-67.783) ENVELOPE(-45.166,-45.166,-60.650,-60.650) ENVELOPE(57.500,57.500,-67.500,-67.500) ENVELOPE(65.000,65.000,-70.000,-70.000) ENVELOPE(62.350,62.350,-67.633,-67.633) ENVELOPE(60.795,60.795,-67.427,-67.427) ENVELOPE(-22.306,-22.306,-80.448,-80.448) |
geographic |
East Antarctica Forbes Rayner Kemp Land MacRobertson Land Forbes Glacier Cape Bruce Kelsey |
geographic_facet |
East Antarctica Forbes Rayner Kemp Land MacRobertson Land Forbes Glacier Cape Bruce Kelsey |
genre |
Antarc* Antarctica East Antarctica Kemp Land MacRobertson Land |
genre_facet |
Antarc* Antarctica East Antarctica Kemp Land MacRobertson Land |
op_source |
http://dx.doi.org/10.1111/j.1525-1314.2007.00723.x |
op_relation |
Journal of Metamorphic Geology, 2007; 25(6):683-701 0263-4929 1525-1314 http://hdl.handle.net/2440/44143 doi:10.1111/j.1525-1314.2007.00723.x |
op_doi |
https://doi.org/10.1111/j.1525-1314.2007.00723.x |
container_title |
Journal of Metamorphic Geology |
container_volume |
25 |
container_issue |
6 |
container_start_page |
683 |
op_container_end_page |
701 |
_version_ |
1786160305175265280 |