Shock metamorphism of quartz at the submarine Mjølnir impact crater, Barents Sea
Abstract— Shock metamorphosed quartz grains have been discovered in a drill core from the central peak of the Late Jurassic, marine Mjølnir structure; this finding further corroborates the impact origin of Mjølnir. The intersected strata represent the Upper Jurassic Hekkingen Formation and underlyin...
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crwiley:10.1111/j.1945-5100.2005.tb00407.x 2023-12-03T10:20:09+01:00 Shock metamorphism of quartz at the submarine Mjølnir impact crater, Barents Sea Sandbakken, Pål T. Langenhorst, Falko Dypvik, Henning 2005 http://dx.doi.org/10.1111/j.1945-5100.2005.tb00407.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1945-5100.2005.tb00407.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1945-5100.2005.tb00407.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Meteoritics & Planetary Science volume 40, issue 9-10, page 1363-1375 ISSN 1086-9379 1945-5100 Space and Planetary Science Geophysics journal-article 2005 crwiley https://doi.org/10.1111/j.1945-5100.2005.tb00407.x 2023-11-09T13:15:38Z Abstract— Shock metamorphosed quartz grains have been discovered in a drill core from the central peak of the Late Jurassic, marine Mjølnir structure; this finding further corroborates the impact origin of Mjølnir. The intersected strata represent the Upper Jurassic Hekkingen Formation and underlying Jurassic and Upper Triassic formations. The appearance, orientation, and origin of shock features in quartz grains and their stratigraphic distribution within the core units have been studied by optical and transmission electron microscopy. The quartz grains contain planar fractures (PFs), planar deformation features (PDFs), and mechanical Brazil twins. The formation of PFs is the predominant shock effect and is attributed to the large impedance differences between the water‐rich pores and constituent minerals in target sediments. This situation may have strengthened tensional/extensional and shear movements during shock compression and decompression. The combination of various shock effects indicates possible shock pressures between 5 and at least 20 GPa for three core units with a total thickness of 86 m (from 74.00 m to 171.09 m core depth). Crater‐fill material from the lower part of the core typically shows the least pressures, whereas the uppermost part of the allochthonous crater deposits displays the highest pressures. The orientations of PFs in studied quartz grains seem to become more diverse as the pressure rises from predominantly (0001) PFs to a combination of (0001), , and orientations. However, the lack of experimental data on porous sedimentary rocks does not allow us to further constrain the shock conditions on the basis of PF orientations. Article in Journal/Newspaper Barents Sea Wiley Online Library (via Crossref) Barents Sea Hekkingen ENVELOPE(17.832,17.832,69.597,69.597) Meteoritics & Planetary Science 40 9-10 1363 1375 |
institution |
Open Polar |
collection |
Wiley Online Library (via Crossref) |
op_collection_id |
crwiley |
language |
English |
topic |
Space and Planetary Science Geophysics |
spellingShingle |
Space and Planetary Science Geophysics Sandbakken, Pål T. Langenhorst, Falko Dypvik, Henning Shock metamorphism of quartz at the submarine Mjølnir impact crater, Barents Sea |
topic_facet |
Space and Planetary Science Geophysics |
description |
Abstract— Shock metamorphosed quartz grains have been discovered in a drill core from the central peak of the Late Jurassic, marine Mjølnir structure; this finding further corroborates the impact origin of Mjølnir. The intersected strata represent the Upper Jurassic Hekkingen Formation and underlying Jurassic and Upper Triassic formations. The appearance, orientation, and origin of shock features in quartz grains and their stratigraphic distribution within the core units have been studied by optical and transmission electron microscopy. The quartz grains contain planar fractures (PFs), planar deformation features (PDFs), and mechanical Brazil twins. The formation of PFs is the predominant shock effect and is attributed to the large impedance differences between the water‐rich pores and constituent minerals in target sediments. This situation may have strengthened tensional/extensional and shear movements during shock compression and decompression. The combination of various shock effects indicates possible shock pressures between 5 and at least 20 GPa for three core units with a total thickness of 86 m (from 74.00 m to 171.09 m core depth). Crater‐fill material from the lower part of the core typically shows the least pressures, whereas the uppermost part of the allochthonous crater deposits displays the highest pressures. The orientations of PFs in studied quartz grains seem to become more diverse as the pressure rises from predominantly (0001) PFs to a combination of (0001), , and orientations. However, the lack of experimental data on porous sedimentary rocks does not allow us to further constrain the shock conditions on the basis of PF orientations. |
format |
Article in Journal/Newspaper |
author |
Sandbakken, Pål T. Langenhorst, Falko Dypvik, Henning |
author_facet |
Sandbakken, Pål T. Langenhorst, Falko Dypvik, Henning |
author_sort |
Sandbakken, Pål T. |
title |
Shock metamorphism of quartz at the submarine Mjølnir impact crater, Barents Sea |
title_short |
Shock metamorphism of quartz at the submarine Mjølnir impact crater, Barents Sea |
title_full |
Shock metamorphism of quartz at the submarine Mjølnir impact crater, Barents Sea |
title_fullStr |
Shock metamorphism of quartz at the submarine Mjølnir impact crater, Barents Sea |
title_full_unstemmed |
Shock metamorphism of quartz at the submarine Mjølnir impact crater, Barents Sea |
title_sort |
shock metamorphism of quartz at the submarine mjølnir impact crater, barents sea |
publisher |
Wiley |
publishDate |
2005 |
url |
http://dx.doi.org/10.1111/j.1945-5100.2005.tb00407.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1945-5100.2005.tb00407.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1945-5100.2005.tb00407.x |
long_lat |
ENVELOPE(17.832,17.832,69.597,69.597) |
geographic |
Barents Sea Hekkingen |
geographic_facet |
Barents Sea Hekkingen |
genre |
Barents Sea |
genre_facet |
Barents Sea |
op_source |
Meteoritics & Planetary Science volume 40, issue 9-10, page 1363-1375 ISSN 1086-9379 1945-5100 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1945-5100.2005.tb00407.x |
container_title |
Meteoritics & Planetary Science |
container_volume |
40 |
container_issue |
9-10 |
container_start_page |
1363 |
op_container_end_page |
1375 |
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1784267568180101120 |