Shocked quartz grains from the Malingen structure, Sweden-Evidence for a twin crater of the Lockne impact structure
(2014) In Meteoritics and Planetary Science 49(6). p.1076-1082- Abstract
- The Malingen structure in Sweden has for a long time been suspected to be the result of an impact; however, no hard evidence, i.e., shock metamorphic features or traces of the impactor, has so far been presented. Here we show that quartz grains displaying planar deformation features (PDFs) oriented along crystallographic planes typical for shock metamorphism are present in drill core samples from the structure. The shocked material was recovered from basement breccias, below the sediment infill, and the distribution of the orientation of the shock-produced PDFs indicates that the studied material experienced low shock pressures. Based on our findings, we can exclude that the material is transported from the nearby Lockne impact structure,... (More)
- The Malingen structure in Sweden has for a long time been suspected to be the result of an impact; however, no hard evidence, i.e., shock metamorphic features or traces of the impactor, has so far been presented. Here we show that quartz grains displaying planar deformation features (PDFs) oriented along crystallographic planes typical for shock metamorphism are present in drill core samples from the structure. The shocked material was recovered from basement breccias, below the sediment infill, and the distribution of the orientation of the shock-produced PDFs indicates that the studied material experienced low shock pressures. Based on our findings, we can exclude that the material is transported from the nearby Lockne impact structure, which means that the Malingen structure is a separate impact structure, the seventh confirmed impact structure in Sweden. Furthermore, sedimentological and biostratigraphic aspects of the deposits that fill the depression at Malingen are very similar to features at the Lockne impact structure. This implies a coeval formation age and thus also the confirmation of the first known marine target doublet impact craters on Earth (i.e., the Lockne-Malingen pair). (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/4609676
- author
- Alwmark, Carl LU ; Alwmark, Sanna LU ; Ormoe, J. and Sturkell, E.
- organization
- publishing date
- 2014
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Meteoritics and Planetary Science
- volume
- 49
- issue
- 6
- pages
- 1076 - 1082
- publisher
- Wiley-Blackwell
- external identifiers
-
- wos:000337625200009
- scopus:84902280765
- ISSN
- 1086-9379
- DOI
- 10.1111/maps.12314
- language
- English
- LU publication?
- yes
- id
- c6c248bc-3301-484c-bcf9-edee240a4c22 (old id 4609676)
- date added to LUP
- 2016-04-01 14:49:03
- date last changed
- 2022-03-29 22:58:13
@article{c6c248bc-3301-484c-bcf9-edee240a4c22,
abstract = {{The Malingen structure in Sweden has for a long time been suspected to be the result of an impact; however, no hard evidence, i.e., shock metamorphic features or traces of the impactor, has so far been presented. Here we show that quartz grains displaying planar deformation features (PDFs) oriented along crystallographic planes typical for shock metamorphism are present in drill core samples from the structure. The shocked material was recovered from basement breccias, below the sediment infill, and the distribution of the orientation of the shock-produced PDFs indicates that the studied material experienced low shock pressures. Based on our findings, we can exclude that the material is transported from the nearby Lockne impact structure, which means that the Malingen structure is a separate impact structure, the seventh confirmed impact structure in Sweden. Furthermore, sedimentological and biostratigraphic aspects of the deposits that fill the depression at Malingen are very similar to features at the Lockne impact structure. This implies a coeval formation age and thus also the confirmation of the first known marine target doublet impact craters on Earth (i.e., the Lockne-Malingen pair).}},
author = {{Alwmark, Carl and Alwmark, Sanna and Ormoe, J. and Sturkell, E.}},
issn = {{1086-9379}},
language = {{eng}},
number = {{6}},
pages = {{1076--1082}},
publisher = {{Wiley-Blackwell}},
series = {{Meteoritics and Planetary Science}},
title = {{Shocked quartz grains from the Malingen structure, Sweden-Evidence for a twin crater of the Lockne impact structure}},
url = {{http://dx.doi.org/10.1111/maps.12314}},
doi = {{10.1111/maps.12314}},
volume = {{49}},
year = {{2014}},
}