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Putative fossil life in a hydrothermal system of the Dellen impact structure, Sweden

Lindgren, Paula LU ; Ivarsson, Magnus LU ; Neubeck, Anna; Broman, Curt; Henkel, Herbert and Holm, Nils G. (2010) In International Journal of Astrobiology 9(3). p.137-146
Abstract

Impact-generated hydrothermal systems are commonly proposed as good candidates for hosting primitive life on early Earth and Mars. However, evidence of fossil microbial colonization in impact-generated hydrothermal systems is rarely reported in the literature. Here we present the occurrence of putative fossil microorganisms in a hydrothermal system of the 89 Ma Dellen impact structure, Sweden. We found the putative fossilized microorganisms hosted in a fine-grained matrix of hydrothermal alteration minerals set in interlinked fractures of an impact breccia. The putative fossils appear as semi-straight to twirled filaments, with a thickness of 1-2 m, and a length between 10 and 100 m. They have an internal structure with segmentation,... (More)

Impact-generated hydrothermal systems are commonly proposed as good candidates for hosting primitive life on early Earth and Mars. However, evidence of fossil microbial colonization in impact-generated hydrothermal systems is rarely reported in the literature. Here we present the occurrence of putative fossil microorganisms in a hydrothermal system of the 89 Ma Dellen impact structure, Sweden. We found the putative fossilized microorganisms hosted in a fine-grained matrix of hydrothermal alteration minerals set in interlinked fractures of an impact breccia. The putative fossils appear as semi-straight to twirled filaments, with a thickness of 1-2 m, and a length between 10 and 100 m. They have an internal structure with segmentation, and branching of filaments occurs frequently. Their composition varies between an outer and an inner layer of a filament, where the inner layer is more iron rich. Our results indicate that hydrothermal systems in impact craters could potentially be capable of supporting microbial life. This could have played an important role for the evolution of life on early Earth and Mars.

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author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Early Earth, early Mars, hydrothermal system, impact structure, microfossils
in
International Journal of Astrobiology
volume
9
issue
3
pages
10 pages
publisher
Cambridge University Press
external identifiers
  • scopus:77954564047
ISSN
1473-5504
DOI
10.1017/S147355041000011X
language
English
LU publication?
no
id
0bce0ffb-daaf-4714-8b85-c74af12fec8b
date added to LUP
2017-06-26 09:56:18
date last changed
2018-05-29 10:54:58
@article{0bce0ffb-daaf-4714-8b85-c74af12fec8b,
  abstract     = {<p>Impact-generated hydrothermal systems are commonly proposed as good candidates for hosting primitive life on early Earth and Mars. However, evidence of fossil microbial colonization in impact-generated hydrothermal systems is rarely reported in the literature. Here we present the occurrence of putative fossil microorganisms in a hydrothermal system of the 89 Ma Dellen impact structure, Sweden. We found the putative fossilized microorganisms hosted in a fine-grained matrix of hydrothermal alteration minerals set in interlinked fractures of an impact breccia. The putative fossils appear as semi-straight to twirled filaments, with a thickness of 1-2 m, and a length between 10 and 100 m. They have an internal structure with segmentation, and branching of filaments occurs frequently. Their composition varies between an outer and an inner layer of a filament, where the inner layer is more iron rich. Our results indicate that hydrothermal systems in impact craters could potentially be capable of supporting microbial life. This could have played an important role for the evolution of life on early Earth and Mars.</p>},
  author       = {Lindgren, Paula and Ivarsson, Magnus and Neubeck, Anna and Broman, Curt and Henkel, Herbert and Holm, Nils G.},
  issn         = {1473-5504},
  keyword      = {Early Earth,early Mars,hydrothermal system,impact structure,microfossils},
  language     = {eng},
  number       = {3},
  pages        = {137--146},
  publisher    = {Cambridge University Press},
  series       = {International Journal of Astrobiology},
  title        = {Putative fossil life in a hydrothermal system of the Dellen impact structure, Sweden},
  url          = {http://dx.doi.org/10.1017/S147355041000011X},
  volume       = {9},
  year         = {2010},
}