Oblique nonvolcanic seafloor spreading in Lena Trough, Arctic Ocean
Passive rifting and the early non-volcanic formation of ocean basins are fundamental aspects of the plate tectonic cycle. Cenozoic plate margins where this has occurred are rare. Here we present new observations from Lena Trough in the Arctic Ocean that bear on the early phase of oceanic spreading i...
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Online Access: | https://digitalcommons.lsu.edu/geo_pubs/980 https://doi.org/10.1029/2011GC003768 https://digitalcommons.lsu.edu/context/geo_pubs/article/1979/viewcontent/980.pdf |
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ftlouisianastuir:oai:digitalcommons.lsu.edu:geo_pubs-1979 2023-06-11T04:09:18+02:00 Oblique nonvolcanic seafloor spreading in Lena Trough, Arctic Ocean Snow, Jonathan E. Hellebrand, Eric Von Der Handt, Anette Nauret, Francois Gao, Yongjun Schenke, Hans Werner 2011-10-01T07:00:00Z application/pdf https://digitalcommons.lsu.edu/geo_pubs/980 https://doi.org/10.1029/2011GC003768 https://digitalcommons.lsu.edu/context/geo_pubs/article/1979/viewcontent/980.pdf unknown LSU Digital Commons https://digitalcommons.lsu.edu/geo_pubs/980 doi:10.1029/2011GC003768 https://digitalcommons.lsu.edu/context/geo_pubs/article/1979/viewcontent/980.pdf Faculty Publications continental rift mantle exposure mid-ocean ridge seafloor spreading text 2011 ftlouisianastuir https://doi.org/10.1029/2011GC003768 2023-05-28T18:24:17Z Passive rifting and the early non-volcanic formation of ocean basins are fundamental aspects of the plate tectonic cycle. Cenozoic plate margins where this has occurred are rare. Here we present new observations from Lena Trough in the Arctic Ocean that bear on the early phase of oceanic spreading in such rifts. Lena Trough is an oblique seafloor rift system bounding the North American and Eurasian plates, and connecting neighboring Gakkel Ridge with the rest of the global mid-ocean ridge system. Mapping and sampling show widespread mantle outcrop along two parallel basement ridges bounded by steeply dipping normal faults. Volcanism is limited to the intersection with Gakkel Ridge and to minor eruption of strongly potassic alkali basalts in a single location. Non-eruptive magmatism is shown by an increase in plagioclase-and vein-bearing lithologies over residual peridotite in the center of Lena Trough. Normal mid-ocean ridge stairstep geometry and obvious low-angle detachments as seen at other ridges are absent. Lena Trough thus is an example of a young nonvolcanic continental rift that is just now beginning the transition to oblique nonvolcanic seafloor spreading. This style of oblique rifting, without the formation of striated large-scale low-angle detachments appears to be a major mode of crust formation on ultraslow spreading ridges. The sharp transition from the continental margins on either side to nonvolcanic rifting, with mantle slab exhumation in the rift may provide a model for the early evolution of oblique continental rifts, such as the Cote d'Ivoire/NE Brazil conjugate margins. Copyright 2011 by the American Geophysical Union. Text Arctic Arctic Ocean LSU Digital Commons (Louisiana State University) Arctic Arctic Ocean Gakkel Ridge ENVELOPE(90.000,90.000,87.000,87.000) Geochemistry, Geophysics, Geosystems 12 10 n/a n/a |
institution |
Open Polar |
collection |
LSU Digital Commons (Louisiana State University) |
op_collection_id |
ftlouisianastuir |
language |
unknown |
topic |
continental rift mantle exposure mid-ocean ridge seafloor spreading |
spellingShingle |
continental rift mantle exposure mid-ocean ridge seafloor spreading Snow, Jonathan E. Hellebrand, Eric Von Der Handt, Anette Nauret, Francois Gao, Yongjun Schenke, Hans Werner Oblique nonvolcanic seafloor spreading in Lena Trough, Arctic Ocean |
topic_facet |
continental rift mantle exposure mid-ocean ridge seafloor spreading |
description |
Passive rifting and the early non-volcanic formation of ocean basins are fundamental aspects of the plate tectonic cycle. Cenozoic plate margins where this has occurred are rare. Here we present new observations from Lena Trough in the Arctic Ocean that bear on the early phase of oceanic spreading in such rifts. Lena Trough is an oblique seafloor rift system bounding the North American and Eurasian plates, and connecting neighboring Gakkel Ridge with the rest of the global mid-ocean ridge system. Mapping and sampling show widespread mantle outcrop along two parallel basement ridges bounded by steeply dipping normal faults. Volcanism is limited to the intersection with Gakkel Ridge and to minor eruption of strongly potassic alkali basalts in a single location. Non-eruptive magmatism is shown by an increase in plagioclase-and vein-bearing lithologies over residual peridotite in the center of Lena Trough. Normal mid-ocean ridge stairstep geometry and obvious low-angle detachments as seen at other ridges are absent. Lena Trough thus is an example of a young nonvolcanic continental rift that is just now beginning the transition to oblique nonvolcanic seafloor spreading. This style of oblique rifting, without the formation of striated large-scale low-angle detachments appears to be a major mode of crust formation on ultraslow spreading ridges. The sharp transition from the continental margins on either side to nonvolcanic rifting, with mantle slab exhumation in the rift may provide a model for the early evolution of oblique continental rifts, such as the Cote d'Ivoire/NE Brazil conjugate margins. Copyright 2011 by the American Geophysical Union. |
format |
Text |
author |
Snow, Jonathan E. Hellebrand, Eric Von Der Handt, Anette Nauret, Francois Gao, Yongjun Schenke, Hans Werner |
author_facet |
Snow, Jonathan E. Hellebrand, Eric Von Der Handt, Anette Nauret, Francois Gao, Yongjun Schenke, Hans Werner |
author_sort |
Snow, Jonathan E. |
title |
Oblique nonvolcanic seafloor spreading in Lena Trough, Arctic Ocean |
title_short |
Oblique nonvolcanic seafloor spreading in Lena Trough, Arctic Ocean |
title_full |
Oblique nonvolcanic seafloor spreading in Lena Trough, Arctic Ocean |
title_fullStr |
Oblique nonvolcanic seafloor spreading in Lena Trough, Arctic Ocean |
title_full_unstemmed |
Oblique nonvolcanic seafloor spreading in Lena Trough, Arctic Ocean |
title_sort |
oblique nonvolcanic seafloor spreading in lena trough, arctic ocean |
publisher |
LSU Digital Commons |
publishDate |
2011 |
url |
https://digitalcommons.lsu.edu/geo_pubs/980 https://doi.org/10.1029/2011GC003768 https://digitalcommons.lsu.edu/context/geo_pubs/article/1979/viewcontent/980.pdf |
long_lat |
ENVELOPE(90.000,90.000,87.000,87.000) |
geographic |
Arctic Arctic Ocean Gakkel Ridge |
geographic_facet |
Arctic Arctic Ocean Gakkel Ridge |
genre |
Arctic Arctic Ocean |
genre_facet |
Arctic Arctic Ocean |
op_source |
Faculty Publications |
op_relation |
https://digitalcommons.lsu.edu/geo_pubs/980 doi:10.1029/2011GC003768 https://digitalcommons.lsu.edu/context/geo_pubs/article/1979/viewcontent/980.pdf |
op_doi |
https://doi.org/10.1029/2011GC003768 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
12 |
container_issue |
10 |
container_start_page |
n/a |
op_container_end_page |
n/a |
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1768383085910425600 |