Contrasting P-T-t paths for Neoproterozoic metamorphism in MacRobertson and Kemp Lands, east Antarctica
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....
Published in: | Journal of Metamorphic Geology |
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Online Access: | https://doi.org/10.1111/j.1525-1314.2007.00723.x http://ecite.utas.edu.au/75908 |
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ftunivtasecite:oai:ecite.utas.edu.au:75908 2023-05-15T14:02:30+02:00 Contrasting P-T-t paths for Neoproterozoic metamorphism in MacRobertson and Kemp Lands, east Antarctica Halpin, JA Clarke, GL White, RW Kelsey, DE 2007 application/pdf https://doi.org/10.1111/j.1525-1314.2007.00723.x http://ecite.utas.edu.au/75908 en eng Blackwell Publishing Ltd http://ecite.utas.edu.au/75908/1/Halpin_et_al_2007b.pdf http://dx.doi.org/10.1111/j.1525-1314.2007.00723.x Halpin, JA and Clarke, GL and White, RW and Kelsey, DE, Contrasting P-T-t paths for Neoproterozoic metamorphism in MacRobertson and Kemp Lands, east Antarctica, Journal of Metamorphic Geology, 25, (6) pp. 683-701. ISSN 0263-4929 (2007) [Refereed Article] http://ecite.utas.edu.au/75908 Earth Sciences Geology Igneous and Metamorphic Petrology Refereed Article PeerReviewed 2007 ftunivtasecite https://doi.org/10.1111/j.1525-1314.2007.00723.x 2019-12-13T21:42:25Z 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. 2007 Blackwell Publishing Ltd. Article in Journal/Newspaper Antarc* Antarctica Antarctica Journal East Antarctica Kemp Land MacRobertson Land eCite UTAS (University of Tasmania) Cape Bruce ENVELOPE(60.795,60.795,-67.427,-67.427) East Antarctica Forbes ENVELOPE(-66.550,-66.550,-67.783,-67.783) Forbes Glacier ENVELOPE(62.350,62.350,-67.633,-67.633) Kemp Land ENVELOPE(57.500,57.500,-67.500,-67.500) MacRobertson Land ENVELOPE(65.000,65.000,-70.000,-70.000) Rayner ENVELOPE(-45.166,-45.166,-60.650,-60.650) Journal of Metamorphic Geology 25 6 683 701 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Geology Igneous and Metamorphic Petrology |
spellingShingle |
Earth Sciences Geology Igneous and Metamorphic Petrology Halpin, JA Clarke, GL White, RW Kelsey, DE Contrasting P-T-t paths for Neoproterozoic metamorphism in MacRobertson and Kemp Lands, east Antarctica |
topic_facet |
Earth Sciences Geology Igneous and Metamorphic Petrology |
description |
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. 2007 Blackwell Publishing Ltd. |
format |
Article in Journal/Newspaper |
author |
Halpin, JA Clarke, GL White, RW Kelsey, DE |
author_facet |
Halpin, JA Clarke, GL White, RW Kelsey, DE |
author_sort |
Halpin, JA |
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 |
https://doi.org/10.1111/j.1525-1314.2007.00723.x http://ecite.utas.edu.au/75908 |
long_lat |
ENVELOPE(60.795,60.795,-67.427,-67.427) ENVELOPE(-66.550,-66.550,-67.783,-67.783) ENVELOPE(62.350,62.350,-67.633,-67.633) ENVELOPE(57.500,57.500,-67.500,-67.500) ENVELOPE(65.000,65.000,-70.000,-70.000) ENVELOPE(-45.166,-45.166,-60.650,-60.650) |
geographic |
Cape Bruce East Antarctica Forbes Forbes Glacier Kemp Land MacRobertson Land Rayner |
geographic_facet |
Cape Bruce East Antarctica Forbes Forbes Glacier Kemp Land MacRobertson Land Rayner |
genre |
Antarc* Antarctica Antarctica Journal East Antarctica Kemp Land MacRobertson Land |
genre_facet |
Antarc* Antarctica Antarctica Journal East Antarctica Kemp Land MacRobertson Land |
op_relation |
http://ecite.utas.edu.au/75908/1/Halpin_et_al_2007b.pdf http://dx.doi.org/10.1111/j.1525-1314.2007.00723.x Halpin, JA and Clarke, GL and White, RW and Kelsey, DE, Contrasting P-T-t paths for Neoproterozoic metamorphism in MacRobertson and Kemp Lands, east Antarctica, Journal of Metamorphic Geology, 25, (6) pp. 683-701. ISSN 0263-4929 (2007) [Refereed Article] http://ecite.utas.edu.au/75908 |
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_ |
1766272784198008832 |