An evaluation of Mesozoic rift-related magmatism on the margins of the Labrador Sea: Implications for rifting and passive margin asymmetry
The Labrador Sea is a small (∼900 km wide) ocean basin separating southwest Greenland from Labrador, Canada. It opened following a series of rifting events that began as early as the Late Triassic or Jurassic, culminating in a brief period of seafloor spreading commencing by polarity chron 27 (C27;...
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ftunivhullir:oai:hull-repository.worktribe.com:968226 2023-05-15T16:26:55+02:00 An evaluation of Mesozoic rift-related magmatism on the margins of the Labrador Sea: Implications for rifting and passive margin asymmetry Peace, Alexander McCaffrey, Ken Imber, Jonathan Phethean, Jordan Nowell, Geoff Gerdes, Keith Dempsey, Edward 2016-09-29 https://hull-repository.worktribe.com/output/968226 https://doi.org/10.1130/GES01341.1 unknown Geological Society of America https://hull-repository.worktribe.com/output/968226 Geosphere Volume 12 Issue 6 Pagination 1701-1724 doi:https://doi.org/10.1130/GES01341.1 1553-040X doi:10.1130/GES01341.1 Energy Environment and Sustainability Specialist Research - Other Journal Article 2016 ftunivhullir https://doi.org/10.1130/GES01341.1 2023-03-26T20:24:33Z The Labrador Sea is a small (∼900 km wide) ocean basin separating southwest Greenland from Labrador, Canada. It opened following a series of rifting events that began as early as the Late Triassic or Jurassic, culminating in a brief period of seafloor spreading commencing by polarity chron 27 (C27; Danian) and ending by C13 (Eocene-Oligocene boundary). Rift-related magmatism has been documented on both conjugate margins of the Labrador Sea. In southwest Greenland this magmatism formed a major coast-parallel dike swarm as well as other smaller dikes and intrusions. Evidence for rift-related magmatism on the conjugate Labrador margin is limited to igneous lithologies found in deep offshore exploration wells, mostly belonging to the Alexis Formation, along with a postulated Early Cretaceous nephelinite dike swarm (ca. 142 Ma) that crops out onshore, near Makkovik, Labrador. Our field observations of this Early Cretaceous nephelinite suite lead us to conclude that the early rift-related magmatism exposed around Makkovik is volumetrically and spatially limited compared to the contemporaneous magmatism on the conjugate southwest Greenland margin. This asymmetry in the spatial extent of the exposed onshore magmatism is consistent with other observations of asymmetry between the conjugate margins of the Labrador Sea, including the total sediment thickness in offshore basins, the crustal structure, and the bathymetric profile of the shelf width. We propose that the magmatic and structural asymmetry observed between these two conjugate margins is consistent with an early rifting phase dominated by simple shear rather than pure shear deformation. In such a setting Labrador would be the lower plate margin to the southwest Greenland upper plate. Article in Journal/Newspaper Greenland Labrador Sea Makkovik University of Hull: Repository@Hull Canada Greenland Makkovik ENVELOPE(-59.178,-59.178,55.087,55.087) Geosphere 12 6 1701 1724 |
institution |
Open Polar |
collection |
University of Hull: Repository@Hull |
op_collection_id |
ftunivhullir |
language |
unknown |
topic |
Energy Environment and Sustainability Specialist Research - Other |
spellingShingle |
Energy Environment and Sustainability Specialist Research - Other Peace, Alexander McCaffrey, Ken Imber, Jonathan Phethean, Jordan Nowell, Geoff Gerdes, Keith Dempsey, Edward An evaluation of Mesozoic rift-related magmatism on the margins of the Labrador Sea: Implications for rifting and passive margin asymmetry |
topic_facet |
Energy Environment and Sustainability Specialist Research - Other |
description |
The Labrador Sea is a small (∼900 km wide) ocean basin separating southwest Greenland from Labrador, Canada. It opened following a series of rifting events that began as early as the Late Triassic or Jurassic, culminating in a brief period of seafloor spreading commencing by polarity chron 27 (C27; Danian) and ending by C13 (Eocene-Oligocene boundary). Rift-related magmatism has been documented on both conjugate margins of the Labrador Sea. In southwest Greenland this magmatism formed a major coast-parallel dike swarm as well as other smaller dikes and intrusions. Evidence for rift-related magmatism on the conjugate Labrador margin is limited to igneous lithologies found in deep offshore exploration wells, mostly belonging to the Alexis Formation, along with a postulated Early Cretaceous nephelinite dike swarm (ca. 142 Ma) that crops out onshore, near Makkovik, Labrador. Our field observations of this Early Cretaceous nephelinite suite lead us to conclude that the early rift-related magmatism exposed around Makkovik is volumetrically and spatially limited compared to the contemporaneous magmatism on the conjugate southwest Greenland margin. This asymmetry in the spatial extent of the exposed onshore magmatism is consistent with other observations of asymmetry between the conjugate margins of the Labrador Sea, including the total sediment thickness in offshore basins, the crustal structure, and the bathymetric profile of the shelf width. We propose that the magmatic and structural asymmetry observed between these two conjugate margins is consistent with an early rifting phase dominated by simple shear rather than pure shear deformation. In such a setting Labrador would be the lower plate margin to the southwest Greenland upper plate. |
format |
Article in Journal/Newspaper |
author |
Peace, Alexander McCaffrey, Ken Imber, Jonathan Phethean, Jordan Nowell, Geoff Gerdes, Keith Dempsey, Edward |
author_facet |
Peace, Alexander McCaffrey, Ken Imber, Jonathan Phethean, Jordan Nowell, Geoff Gerdes, Keith Dempsey, Edward |
author_sort |
Peace, Alexander |
title |
An evaluation of Mesozoic rift-related magmatism on the margins of the Labrador Sea: Implications for rifting and passive margin asymmetry |
title_short |
An evaluation of Mesozoic rift-related magmatism on the margins of the Labrador Sea: Implications for rifting and passive margin asymmetry |
title_full |
An evaluation of Mesozoic rift-related magmatism on the margins of the Labrador Sea: Implications for rifting and passive margin asymmetry |
title_fullStr |
An evaluation of Mesozoic rift-related magmatism on the margins of the Labrador Sea: Implications for rifting and passive margin asymmetry |
title_full_unstemmed |
An evaluation of Mesozoic rift-related magmatism on the margins of the Labrador Sea: Implications for rifting and passive margin asymmetry |
title_sort |
evaluation of mesozoic rift-related magmatism on the margins of the labrador sea: implications for rifting and passive margin asymmetry |
publisher |
Geological Society of America |
publishDate |
2016 |
url |
https://hull-repository.worktribe.com/output/968226 https://doi.org/10.1130/GES01341.1 |
long_lat |
ENVELOPE(-59.178,-59.178,55.087,55.087) |
geographic |
Canada Greenland Makkovik |
geographic_facet |
Canada Greenland Makkovik |
genre |
Greenland Labrador Sea Makkovik |
genre_facet |
Greenland Labrador Sea Makkovik |
op_relation |
https://hull-repository.worktribe.com/output/968226 Geosphere Volume 12 Issue 6 Pagination 1701-1724 doi:https://doi.org/10.1130/GES01341.1 1553-040X doi:10.1130/GES01341.1 |
op_doi |
https://doi.org/10.1130/GES01341.1 |
container_title |
Geosphere |
container_volume |
12 |
container_issue |
6 |
container_start_page |
1701 |
op_container_end_page |
1724 |
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1766015931498102784 |