Jurassic failed rift system below the Filchner-Ronne-Shelf, Antarctica: New evidence from geophysical data
During the austral summer of 1994/95, reasonable ice conditions in the Weddell Sea allowed the acquisition of new high quality seismic refraction data parallel to the Filchner-Ronne Ice Shelf (FRS), Antarctica. Although pack ice conditions resulted in some data gaps, the final velocity-depth/2D-dens...
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ftawi:oai:epic.awi.de:41698 2024-09-15T17:41:09+00:00 Jurassic failed rift system below the Filchner-Ronne-Shelf, Antarctica: New evidence from geophysical data Jokat, Wilfried Herter, Ulrich 2016-09-14 https://epic.awi.de/id/eprint/41698/ https://hdl.handle.net/10013/epic.48627 unknown ELSEVIER SCIENCE BV Jokat, W. orcid:0000-0002-7793-5854 and Herter, U. (2016) Jurassic failed rift system below the Filchner-Ronne-Shelf, Antarctica: New evidence from geophysical data , Tectonophysics, 688 , pp. 65-83 . doi:10.1016/j.tecto.2016.09.018 <https://doi.org/10.1016/j.tecto.2016.09.018> , hdl:10013/epic.48627 EPIC3Tectonophysics, ELSEVIER SCIENCE BV, 688, pp. 65-83, ISSN: 0040-1951 Article isiRev 2016 ftawi https://doi.org/10.1016/j.tecto.2016.09.018 2024-06-24T04:15:36Z During the austral summer of 1994/95, reasonable ice conditions in the Weddell Sea allowed the acquisition of new high quality seismic refraction data parallel to the Filchner-Ronne Ice Shelf (FRS), Antarctica. Although pack ice conditions resulted in some data gaps, the final velocity-depth/2D-density models cover the entire FRS in E-W direction using all available deep seismic data/picks from this remote area. The velocity-depth model shows a sedimentary basin with a thickness up to 12 km and a large velocity inversion in the lowermost sedimentary unit. The crustal thickness reaches a maximum of 40 km along the basin’s margins in the Antarctic Peninsula and East Antarctica. In the central shelf area, numerous interfering seismic phases occur from the crust-mantle boundary at decreasing distances indicating a thinning of the crust. Here, the modelled velocities and densities reveal a thickness of 20 km for the igneous crust. This corridor of overthickened oceanic or close to oceanic crust is 160 km wide. The corridor is characterized by weak, but in general continuous magnetic anomalies, which we interpret as isochrons developed during the rifting or the initial formation of oceanic crust. If the crustal composition represents an old stripe of oceanic crust, a minimum estimate for the early formation of the oceanic crust is 145/148 Ma (Late Jurassic). However, based on the velocity of rift propagation during the initial opening of the adjacent Weddell Sea the oceanic crust is likely to have formed around 160 Ma. The onset of rifting and development of a thick igneous crust can be related to stresses developed between the interior and the southwestern paleo-Pacific subduction margin of the fragmenting Gondwana supercontinent in combination with additional melt supply from a deeper mantle source that arrived and spread in the period 183-155 Ma. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctica East Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Shelf Ronne Ice Shelf Weddell Sea Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Tectonophysics 688 65 83 |
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Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
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ftawi |
language |
unknown |
description |
During the austral summer of 1994/95, reasonable ice conditions in the Weddell Sea allowed the acquisition of new high quality seismic refraction data parallel to the Filchner-Ronne Ice Shelf (FRS), Antarctica. Although pack ice conditions resulted in some data gaps, the final velocity-depth/2D-density models cover the entire FRS in E-W direction using all available deep seismic data/picks from this remote area. The velocity-depth model shows a sedimentary basin with a thickness up to 12 km and a large velocity inversion in the lowermost sedimentary unit. The crustal thickness reaches a maximum of 40 km along the basin’s margins in the Antarctic Peninsula and East Antarctica. In the central shelf area, numerous interfering seismic phases occur from the crust-mantle boundary at decreasing distances indicating a thinning of the crust. Here, the modelled velocities and densities reveal a thickness of 20 km for the igneous crust. This corridor of overthickened oceanic or close to oceanic crust is 160 km wide. The corridor is characterized by weak, but in general continuous magnetic anomalies, which we interpret as isochrons developed during the rifting or the initial formation of oceanic crust. If the crustal composition represents an old stripe of oceanic crust, a minimum estimate for the early formation of the oceanic crust is 145/148 Ma (Late Jurassic). However, based on the velocity of rift propagation during the initial opening of the adjacent Weddell Sea the oceanic crust is likely to have formed around 160 Ma. The onset of rifting and development of a thick igneous crust can be related to stresses developed between the interior and the southwestern paleo-Pacific subduction margin of the fragmenting Gondwana supercontinent in combination with additional melt supply from a deeper mantle source that arrived and spread in the period 183-155 Ma. |
format |
Article in Journal/Newspaper |
author |
Jokat, Wilfried Herter, Ulrich |
spellingShingle |
Jokat, Wilfried Herter, Ulrich Jurassic failed rift system below the Filchner-Ronne-Shelf, Antarctica: New evidence from geophysical data |
author_facet |
Jokat, Wilfried Herter, Ulrich |
author_sort |
Jokat, Wilfried |
title |
Jurassic failed rift system below the Filchner-Ronne-Shelf, Antarctica: New evidence from geophysical data |
title_short |
Jurassic failed rift system below the Filchner-Ronne-Shelf, Antarctica: New evidence from geophysical data |
title_full |
Jurassic failed rift system below the Filchner-Ronne-Shelf, Antarctica: New evidence from geophysical data |
title_fullStr |
Jurassic failed rift system below the Filchner-Ronne-Shelf, Antarctica: New evidence from geophysical data |
title_full_unstemmed |
Jurassic failed rift system below the Filchner-Ronne-Shelf, Antarctica: New evidence from geophysical data |
title_sort |
jurassic failed rift system below the filchner-ronne-shelf, antarctica: new evidence from geophysical data |
publisher |
ELSEVIER SCIENCE BV |
publishDate |
2016 |
url |
https://epic.awi.de/id/eprint/41698/ https://hdl.handle.net/10013/epic.48627 |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica East Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Shelf Ronne Ice Shelf Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica East Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Shelf Ronne Ice Shelf Weddell Sea |
op_source |
EPIC3Tectonophysics, ELSEVIER SCIENCE BV, 688, pp. 65-83, ISSN: 0040-1951 |
op_relation |
Jokat, W. orcid:0000-0002-7793-5854 and Herter, U. (2016) Jurassic failed rift system below the Filchner-Ronne-Shelf, Antarctica: New evidence from geophysical data , Tectonophysics, 688 , pp. 65-83 . doi:10.1016/j.tecto.2016.09.018 <https://doi.org/10.1016/j.tecto.2016.09.018> , hdl:10013/epic.48627 |
op_doi |
https://doi.org/10.1016/j.tecto.2016.09.018 |
container_title |
Tectonophysics |
container_volume |
688 |
container_start_page |
65 |
op_container_end_page |
83 |
_version_ |
1810487266239315968 |