Provenance Response to Rifting and Separation at the Jan Mayen Microcontinent Margin
The Eocene-Miocene successions recovered at DSDP sites on the Jan Mayen Ridge (NE Atlantic) and on the adjacent East Greenland margin provide a sedimentary record of the rifting and separation of the Jan Mayen Microcontinent from East Greenland. A combination of palynology, conventional heavy minera...
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ftmdpi:oai:mdpi.com:/2076-3263/12/9/326/ 2023-08-20T04:06:12+02:00 Provenance Response to Rifting and Separation at the Jan Mayen Microcontinent Margin Andrew Morton David W. Jolley Adam G. Szulc Andrew G. Whitham Dominic P. Strogen C. Mark Fanning Sidney R. Hemming agris 2022-08-29 application/pdf https://doi.org/10.3390/geosciences12090326 EN eng Multidisciplinary Digital Publishing Institute Sedimentology, Stratigraphy and Palaeontology https://dx.doi.org/10.3390/geosciences12090326 https://creativecommons.org/licenses/by/4.0/ Geosciences; Volume 12; Issue 9; Pages: 326 East Greenland Jan Mayen North Atlantic rifting provenance Eocene Oligocene Text 2022 ftmdpi https://doi.org/10.3390/geosciences12090326 2023-08-01T06:16:12Z The Eocene-Miocene successions recovered at DSDP sites on the Jan Mayen Ridge (NE Atlantic) and on the adjacent East Greenland margin provide a sedimentary record of the rifting and separation of the Jan Mayen Microcontinent from East Greenland. A combination of palynology, conventional heavy mineral analysis, single-grain major and trace element geochemistry and radiometric dating of amphibole and zircon has revealed a major change in sediment provenance took place at the Early/Late Oligocene boundary corresponding to a prominent seismic reflector termed JA. During the Eocene and Early Oligocene, lateral variations in provenance character indicate multiple, small-scale transport systems. Site 349 and Kap Brewster were predominantly supplied from magmatic sources (Kap Brewster having a stronger subalkaline signature compared with Site 349), whereas Site 346 received almost exclusively metasedimentary detritus. By contrast, Late Oligocene provenance characteristics are closely comparable at the two Jan Mayen sites, the most distinctive feature being the abundance of reworked Carboniferous, Jurassic, Cretaceous and Eocene palynomorphs. The Site 349 succession documents an evolution in the nature of the magmatic provenance component. Supply from evolved alkaline magmatic rocks, such as syenites, was important in the Middle Eocene and lower part of the Early Oligocene, but was superseded in the later Early Oligocene by mafic magmatic sources. In the latest Early Oligocene, the presence of evolved clinopyroxenes provides evidence for prolonged magmatic fractionation. Initial low degrees of partial melting led to generation of alkaline (syenitic) magmas. The extent of partial melting increased during the Early Oligocene, generating basaltic rocks with both subalkaline and alkaline compositions. Towards the end of the Early Oligocene, the amount of partial melting and magma supply rates decreased. In the Late Oligocene, there is no evidence for contemporaneous igneous activity, with scarce magmatic indicator minerals. ... Text East Greenland Greenland Jan Mayen Kap Brewster North Atlantic MDPI Open Access Publishing Greenland Jan Mayen Kap ENVELOPE(23.567,23.567,65.533,65.533) Brewster ENVELOPE(169.383,169.383,-72.950,-72.950) Jan Mayen Ridge ENVELOPE(-8.000,-8.000,69.000,69.000) Kap Brewster ENVELOPE(-22.060,-22.060,70.152,70.152) Geosciences 12 9 326 |
institution |
Open Polar |
collection |
MDPI Open Access Publishing |
op_collection_id |
ftmdpi |
language |
English |
topic |
East Greenland Jan Mayen North Atlantic rifting provenance Eocene Oligocene |
spellingShingle |
East Greenland Jan Mayen North Atlantic rifting provenance Eocene Oligocene Andrew Morton David W. Jolley Adam G. Szulc Andrew G. Whitham Dominic P. Strogen C. Mark Fanning Sidney R. Hemming Provenance Response to Rifting and Separation at the Jan Mayen Microcontinent Margin |
topic_facet |
East Greenland Jan Mayen North Atlantic rifting provenance Eocene Oligocene |
description |
The Eocene-Miocene successions recovered at DSDP sites on the Jan Mayen Ridge (NE Atlantic) and on the adjacent East Greenland margin provide a sedimentary record of the rifting and separation of the Jan Mayen Microcontinent from East Greenland. A combination of palynology, conventional heavy mineral analysis, single-grain major and trace element geochemistry and radiometric dating of amphibole and zircon has revealed a major change in sediment provenance took place at the Early/Late Oligocene boundary corresponding to a prominent seismic reflector termed JA. During the Eocene and Early Oligocene, lateral variations in provenance character indicate multiple, small-scale transport systems. Site 349 and Kap Brewster were predominantly supplied from magmatic sources (Kap Brewster having a stronger subalkaline signature compared with Site 349), whereas Site 346 received almost exclusively metasedimentary detritus. By contrast, Late Oligocene provenance characteristics are closely comparable at the two Jan Mayen sites, the most distinctive feature being the abundance of reworked Carboniferous, Jurassic, Cretaceous and Eocene palynomorphs. The Site 349 succession documents an evolution in the nature of the magmatic provenance component. Supply from evolved alkaline magmatic rocks, such as syenites, was important in the Middle Eocene and lower part of the Early Oligocene, but was superseded in the later Early Oligocene by mafic magmatic sources. In the latest Early Oligocene, the presence of evolved clinopyroxenes provides evidence for prolonged magmatic fractionation. Initial low degrees of partial melting led to generation of alkaline (syenitic) magmas. The extent of partial melting increased during the Early Oligocene, generating basaltic rocks with both subalkaline and alkaline compositions. Towards the end of the Early Oligocene, the amount of partial melting and magma supply rates decreased. In the Late Oligocene, there is no evidence for contemporaneous igneous activity, with scarce magmatic indicator minerals. ... |
format |
Text |
author |
Andrew Morton David W. Jolley Adam G. Szulc Andrew G. Whitham Dominic P. Strogen C. Mark Fanning Sidney R. Hemming |
author_facet |
Andrew Morton David W. Jolley Adam G. Szulc Andrew G. Whitham Dominic P. Strogen C. Mark Fanning Sidney R. Hemming |
author_sort |
Andrew Morton |
title |
Provenance Response to Rifting and Separation at the Jan Mayen Microcontinent Margin |
title_short |
Provenance Response to Rifting and Separation at the Jan Mayen Microcontinent Margin |
title_full |
Provenance Response to Rifting and Separation at the Jan Mayen Microcontinent Margin |
title_fullStr |
Provenance Response to Rifting and Separation at the Jan Mayen Microcontinent Margin |
title_full_unstemmed |
Provenance Response to Rifting and Separation at the Jan Mayen Microcontinent Margin |
title_sort |
provenance response to rifting and separation at the jan mayen microcontinent margin |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2022 |
url |
https://doi.org/10.3390/geosciences12090326 |
op_coverage |
agris |
long_lat |
ENVELOPE(23.567,23.567,65.533,65.533) ENVELOPE(169.383,169.383,-72.950,-72.950) ENVELOPE(-8.000,-8.000,69.000,69.000) ENVELOPE(-22.060,-22.060,70.152,70.152) |
geographic |
Greenland Jan Mayen Kap Brewster Jan Mayen Ridge Kap Brewster |
geographic_facet |
Greenland Jan Mayen Kap Brewster Jan Mayen Ridge Kap Brewster |
genre |
East Greenland Greenland Jan Mayen Kap Brewster North Atlantic |
genre_facet |
East Greenland Greenland Jan Mayen Kap Brewster North Atlantic |
op_source |
Geosciences; Volume 12; Issue 9; Pages: 326 |
op_relation |
Sedimentology, Stratigraphy and Palaeontology https://dx.doi.org/10.3390/geosciences12090326 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/geosciences12090326 |
container_title |
Geosciences |
container_volume |
12 |
container_issue |
9 |
container_start_page |
326 |
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1774717140935376896 |