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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ftunivtasmania:oai:eprints.utas.edu.au:6557 2023-05-15T13:36:46+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 2007-08 application/pdf https://eprints.utas.edu.au/6557/ https://eprints.utas.edu.au/6557/1/Halpin_et_al_2007b.pdf https://onlinelibrary.wiley.com/doi/full/10.1111/j.1525-1314.2007.00723.x en eng https://eprints.utas.edu.au/6557/1/Halpin_et_al_2007b.pdf Halpin, JA, Clarke, GL, White, RW and Kelsey, DE 2007 , 'Contrasting P–T–t paths for Neoproterozoic metamorphism in MacRobertson and Kemp Lands, east Antarctica' , Journal of Metamorphic Geology, vol. 25, no. 6 , pp. 683-701 , doi:10.1111/j.1525-1314.2007.00723.x <http://dx.doi.org/10.1111/j.1525-1314.2007.00723.x>. cc_utas 260100 Geology electron microprobe monazite dating granulite NCKFMASHTO pseudosection Rayner Complex Article PeerReviewed 2007 ftunivtasmania https://doi.org/10.1111/j.1525-1314.2007.00723.x 2020-05-30T07:20:22Z 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 ºC and 5.6–6.2 kbar at Cape Bruce, and 900 ºC 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. Article in Journal/Newspaper Antarc* Antarctica Antarctica Journal East Antarctica Kemp Land MacRobertson Land University of Tasmania: UTas ePrints 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) Journal of Metamorphic Geology 25 6 683 701 |
institution |
Open Polar |
collection |
University of Tasmania: UTas ePrints |
op_collection_id |
ftunivtasmania |
language |
English |
topic |
260100 Geology electron microprobe monazite dating granulite NCKFMASHTO pseudosection Rayner Complex |
spellingShingle |
260100 Geology electron microprobe monazite dating granulite NCKFMASHTO pseudosection Rayner Complex 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 |
260100 Geology electron microprobe monazite dating granulite NCKFMASHTO pseudosection Rayner Complex |
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 ºC and 5.6–6.2 kbar at Cape Bruce, and 900 ºC 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. |
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 |
publishDate |
2007 |
url |
https://eprints.utas.edu.au/6557/ https://eprints.utas.edu.au/6557/1/Halpin_et_al_2007b.pdf https://onlinelibrary.wiley.com/doi/full/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) |
geographic |
East Antarctica Forbes Rayner Kemp Land MacRobertson Land Forbes Glacier Cape Bruce |
geographic_facet |
East Antarctica Forbes Rayner Kemp Land MacRobertson Land Forbes Glacier Cape Bruce |
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 |
https://eprints.utas.edu.au/6557/1/Halpin_et_al_2007b.pdf Halpin, JA, Clarke, GL, White, RW and Kelsey, DE 2007 , 'Contrasting P–T–t paths for Neoproterozoic metamorphism in MacRobertson and Kemp Lands, east Antarctica' , Journal of Metamorphic Geology, vol. 25, no. 6 , pp. 683-701 , doi:10.1111/j.1525-1314.2007.00723.x <http://dx.doi.org/10.1111/j.1525-1314.2007.00723.x>. |
op_rights |
cc_utas |
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 |
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1766083812837556224 |