Postcollisional High-Grade Metamorphism, Orogenic Collapse, and Differential Cooling of the East African Orogen of Northeast Mozambique
The postcollisional tectonic development of northeast Mozambique and subsequent cooling from high-temperature metamorphism is delineated with an extensive new set of U-Pb titanite, 40Ar/39Ar hornblende, and 40Ar/39Ar mica analyses. The complex data suggest a polyphase metamorphic history from the la...
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University of Chicago Press
2012
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Online Access: | https://hdl.handle.net/20.500.11937/40907 https://doi.org/10.1086/666876 |
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ftcurtin:oai:espace.curtin.edu.au:20.500.11937/40907 2023-06-11T04:05:16+02:00 Postcollisional High-Grade Metamorphism, Orogenic Collapse, and Differential Cooling of the East African Orogen of Northeast Mozambique Ueda, K. Jacobs, J. Thomas, R. Kosler, J. Horstwood, M. Wartho, J. Jourdan, Fred Emmel, B. Matola, R. 2012 fulltext https://hdl.handle.net/20.500.11937/40907 https://doi.org/10.1086/666876 unknown University of Chicago Press http://hdl.handle.net/20.500.11937/40907 doi:10.1086/666876 Journal Article 2012 ftcurtin https://doi.org/20.500.11937/4090710.1086/666876 2023-05-30T19:41:40Z The postcollisional tectonic development of northeast Mozambique and subsequent cooling from high-temperature metamorphism is delineated with an extensive new set of U-Pb titanite, 40Ar/39Ar hornblende, and 40Ar/39Ar mica analyses. The complex data suggest a polyphase metamorphic history from the late Neoproterozoic to the Ordovician within the East African–Antarctic Orogen (EAAO), with marked differences between the major constituent blocks. In all the data sets, samples from the basement south of the Lúrio Belt show generally younger ages than those from the north, resulting from a late metamorphic event and slow cooling between ca. 520 and 440 Ma. The ages north and south of the Lúrio Belt are consistently offset by ca. 30–70 Ma, a difference that is maintained and even appears to increase during cooling from very high temperatures to ca. 350 °C. Based on the first-order assumption that all the ages are cooling ages, cooling rates in the south are estimated at ca. 7–8 °C/Ma, while those north of the Lúrio Belt are faster at ca. 16 °C/Ma. The data are consistent with previous geochronological, petrographic, and field data and suggest a late high-temperature/low-pressure metamorphic event that affected only the basement rocks south of the Lurio Belt and portions of the latter. This late metamorphism and subsequent delayed, slower cooling agree well with a model of elevated heat flow following lithosphere delamination in the southern part of the orogen, which also explains the observed widespread granitoid magmatism, migmatization, and renewed deformation in the southern basement. Article in Journal/Newspaper Antarc* Antarctic Curtin University: espace Antarctic The Journal of Geology 120 5 507 530 |
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Curtin University: espace |
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ftcurtin |
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description |
The postcollisional tectonic development of northeast Mozambique and subsequent cooling from high-temperature metamorphism is delineated with an extensive new set of U-Pb titanite, 40Ar/39Ar hornblende, and 40Ar/39Ar mica analyses. The complex data suggest a polyphase metamorphic history from the late Neoproterozoic to the Ordovician within the East African–Antarctic Orogen (EAAO), with marked differences between the major constituent blocks. In all the data sets, samples from the basement south of the Lúrio Belt show generally younger ages than those from the north, resulting from a late metamorphic event and slow cooling between ca. 520 and 440 Ma. The ages north and south of the Lúrio Belt are consistently offset by ca. 30–70 Ma, a difference that is maintained and even appears to increase during cooling from very high temperatures to ca. 350 °C. Based on the first-order assumption that all the ages are cooling ages, cooling rates in the south are estimated at ca. 7–8 °C/Ma, while those north of the Lúrio Belt are faster at ca. 16 °C/Ma. The data are consistent with previous geochronological, petrographic, and field data and suggest a late high-temperature/low-pressure metamorphic event that affected only the basement rocks south of the Lurio Belt and portions of the latter. This late metamorphism and subsequent delayed, slower cooling agree well with a model of elevated heat flow following lithosphere delamination in the southern part of the orogen, which also explains the observed widespread granitoid magmatism, migmatization, and renewed deformation in the southern basement. |
format |
Article in Journal/Newspaper |
author |
Ueda, K. Jacobs, J. Thomas, R. Kosler, J. Horstwood, M. Wartho, J. Jourdan, Fred Emmel, B. Matola, R. |
spellingShingle |
Ueda, K. Jacobs, J. Thomas, R. Kosler, J. Horstwood, M. Wartho, J. Jourdan, Fred Emmel, B. Matola, R. Postcollisional High-Grade Metamorphism, Orogenic Collapse, and Differential Cooling of the East African Orogen of Northeast Mozambique |
author_facet |
Ueda, K. Jacobs, J. Thomas, R. Kosler, J. Horstwood, M. Wartho, J. Jourdan, Fred Emmel, B. Matola, R. |
author_sort |
Ueda, K. |
title |
Postcollisional High-Grade Metamorphism, Orogenic Collapse, and Differential Cooling of the East African Orogen of Northeast Mozambique |
title_short |
Postcollisional High-Grade Metamorphism, Orogenic Collapse, and Differential Cooling of the East African Orogen of Northeast Mozambique |
title_full |
Postcollisional High-Grade Metamorphism, Orogenic Collapse, and Differential Cooling of the East African Orogen of Northeast Mozambique |
title_fullStr |
Postcollisional High-Grade Metamorphism, Orogenic Collapse, and Differential Cooling of the East African Orogen of Northeast Mozambique |
title_full_unstemmed |
Postcollisional High-Grade Metamorphism, Orogenic Collapse, and Differential Cooling of the East African Orogen of Northeast Mozambique |
title_sort |
postcollisional high-grade metamorphism, orogenic collapse, and differential cooling of the east african orogen of northeast mozambique |
publisher |
University of Chicago Press |
publishDate |
2012 |
url |
https://hdl.handle.net/20.500.11937/40907 https://doi.org/10.1086/666876 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
http://hdl.handle.net/20.500.11937/40907 doi:10.1086/666876 |
op_doi |
https://doi.org/20.500.11937/4090710.1086/666876 |
container_title |
The Journal of Geology |
container_volume |
120 |
container_issue |
5 |
container_start_page |
507 |
op_container_end_page |
530 |
_version_ |
1768373526226534400 |