The Donkerhuk batholith, Namibia: A giant S-type granite emplaced in the mid crust, in a fore-arc setting
The mainly S-type Donkerhuk batholith intruded the accretionary prism in the Pan-African Damara Belt of Namibia. The batholith is elongate parallel to the regional SW–NE structural grain and the Okahandja Lineament Zone, which forms the accretionary prism backstop and the magma feeder zone. Over 500...
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ftdatacite:10.6084/m9.figshare.c.3470880 2023-05-15T17:04:42+02:00 The Donkerhuk batholith, Namibia: A giant S-type granite emplaced in the mid crust, in a fore-arc setting J.D. Clemens I.S. Buick A.F.M. Kisters 2016 https://dx.doi.org/10.6084/m9.figshare.c.3470880 https://figshare.com/collections/The_Donkerhuk_batholith_Namibia_A_giant_S-type_granite_emplaced_in_the_mid_crust_in_a_fore-arc_setting/3470880 unknown Figshare https://dx.doi.org/10.1144/jgs2016-028 CC-BY https://creativecommons.org/licenses/by/4.0 CC-BY Geology FOS Earth and related environmental sciences Collection article 2016 ftdatacite https://doi.org/10.6084/m9.figshare.c.3470880 https://doi.org/10.1144/jgs2016-028 2021-11-05T12:55:41Z The mainly S-type Donkerhuk batholith intruded the accretionary prism in the Pan-African Damara Belt of Namibia. The batholith is elongate parallel to the regional SW–NE structural grain and the Okahandja Lineament Zone, which forms the accretionary prism backstop and the magma feeder zone. Over 5000 km 3 of granitic magmas were emplaced as thousands of sheets, over perhaps 20 myr, with sheet orientations determined by the regional stress field and wall-rock anisotropies. Some of the magma source rocks are inferred to have been cordierite-bearing, suggesting an upper pressure limit of 600 MPa (6 kbar). Calculated phase relations suggest magma emplacement at 450 MPa (4.5 kbar), corroborated by pseudosection modelling of the phase assemblage in a migmatitic wall rock. The magmas were initially highly H 2 O undersaturated and at around 850°C, indicating fluid-absent conditions in the source rocks. This suggests intraplating of mantle magmas to provide heat and that the granitic magmas ascended only to the mid crust. The late-tectonic emplacement in a forearc shares similarities with younger and similarly large batholiths such as the Cretaceous Kodiak batholith in Alaska, but the internal architecture and age structure of the batholiths differ markedly, suggesting that different processes can trigger voluminous near-trench plutonism. Article in Journal/Newspaper Kodiak Alaska DataCite Metadata Store (German National Library of Science and Technology) |
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Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
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language |
unknown |
topic |
Geology FOS Earth and related environmental sciences |
spellingShingle |
Geology FOS Earth and related environmental sciences J.D. Clemens I.S. Buick A.F.M. Kisters The Donkerhuk batholith, Namibia: A giant S-type granite emplaced in the mid crust, in a fore-arc setting |
topic_facet |
Geology FOS Earth and related environmental sciences |
description |
The mainly S-type Donkerhuk batholith intruded the accretionary prism in the Pan-African Damara Belt of Namibia. The batholith is elongate parallel to the regional SW–NE structural grain and the Okahandja Lineament Zone, which forms the accretionary prism backstop and the magma feeder zone. Over 5000 km 3 of granitic magmas were emplaced as thousands of sheets, over perhaps 20 myr, with sheet orientations determined by the regional stress field and wall-rock anisotropies. Some of the magma source rocks are inferred to have been cordierite-bearing, suggesting an upper pressure limit of 600 MPa (6 kbar). Calculated phase relations suggest magma emplacement at 450 MPa (4.5 kbar), corroborated by pseudosection modelling of the phase assemblage in a migmatitic wall rock. The magmas were initially highly H 2 O undersaturated and at around 850°C, indicating fluid-absent conditions in the source rocks. This suggests intraplating of mantle magmas to provide heat and that the granitic magmas ascended only to the mid crust. The late-tectonic emplacement in a forearc shares similarities with younger and similarly large batholiths such as the Cretaceous Kodiak batholith in Alaska, but the internal architecture and age structure of the batholiths differ markedly, suggesting that different processes can trigger voluminous near-trench plutonism. |
format |
Article in Journal/Newspaper |
author |
J.D. Clemens I.S. Buick A.F.M. Kisters |
author_facet |
J.D. Clemens I.S. Buick A.F.M. Kisters |
author_sort |
J.D. Clemens |
title |
The Donkerhuk batholith, Namibia: A giant S-type granite emplaced in the mid crust, in a fore-arc setting |
title_short |
The Donkerhuk batholith, Namibia: A giant S-type granite emplaced in the mid crust, in a fore-arc setting |
title_full |
The Donkerhuk batholith, Namibia: A giant S-type granite emplaced in the mid crust, in a fore-arc setting |
title_fullStr |
The Donkerhuk batholith, Namibia: A giant S-type granite emplaced in the mid crust, in a fore-arc setting |
title_full_unstemmed |
The Donkerhuk batholith, Namibia: A giant S-type granite emplaced in the mid crust, in a fore-arc setting |
title_sort |
donkerhuk batholith, namibia: a giant s-type granite emplaced in the mid crust, in a fore-arc setting |
publisher |
Figshare |
publishDate |
2016 |
url |
https://dx.doi.org/10.6084/m9.figshare.c.3470880 https://figshare.com/collections/The_Donkerhuk_batholith_Namibia_A_giant_S-type_granite_emplaced_in_the_mid_crust_in_a_fore-arc_setting/3470880 |
genre |
Kodiak Alaska |
genre_facet |
Kodiak Alaska |
op_relation |
https://dx.doi.org/10.1144/jgs2016-028 |
op_rights |
CC-BY https://creativecommons.org/licenses/by/4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.6084/m9.figshare.c.3470880 https://doi.org/10.1144/jgs2016-028 |
_version_ |
1766059023657861120 |