Petrography and field relationships of impact lithologies at the Gardnos impact structure, Norway
Jaret, Steven J. ; Hyde, William R. LU
and Shteynman, Leah
(2025)
In Meteoritics and Planetary Science
- Abstract
New mapping and laboratory studies of the impactites at the Gardnos impact structure (Norway) show a variety of impact-deformed rocks. Our mapping and petrographic analyses have subdivided these breccias into three distinct categories: (a) melt-bearing sueivitic breccias, melt-bearing polymict breccias; (b) melt-free, polymict lithic impact breccias; and (c) monomict lithic impact breccias. This illustrates the dynamic nature of crater floor processes where mixing occurs in multiple ways. Feldspar grains exhibit evidence of intense shear, micro-faults, and alternate twin deformation in feldspar. We also observe the development of additional, amphibole-like planar elements (or cleavage) in biotite. Melt-bearing breccias contain carbon... (More)
New mapping and laboratory studies of the impactites at the Gardnos impact structure (Norway) show a variety of impact-deformed rocks. Our mapping and petrographic analyses have subdivided these breccias into three distinct categories: (a) melt-bearing sueivitic breccias, melt-bearing polymict breccias; (b) melt-free, polymict lithic impact breccias; and (c) monomict lithic impact breccias. This illustrates the dynamic nature of crater floor processes where mixing occurs in multiple ways. Feldspar grains exhibit evidence of intense shear, micro-faults, and alternate twin deformation in feldspar. We also observe the development of additional, amphibole-like planar elements (or cleavage) in biotite. Melt-bearing breccias contain carbon concentrations up to an order of magnitude higher than the target rocks. Unusual textures of carbon petrographically associated with shock and post-shock features in feldspars suggest significant postimpact hydrothermal mobilization of carbon within these rocks. Gardnos, therefore, represents an important terrestrial analog for understanding a suite of impact- and postimpact geologic processes.
(Less)
- author
- Jaret, Steven J.
; Hyde, William R.
LU
and Shteynman, Leah
- organization
- publishing date
- 2025
- type
- Contribution to journal
- publication status
- epub
- subject
- in
- Meteoritics and Planetary Science
- pages
- 19 pages
- publisher
- Wiley-Blackwell
- external identifiers
-
- scopus:105004766786
- ISSN
- 1086-9379
- DOI
- 10.1111/maps.14354
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2025 The Meteoritical Society.
- id
- 32238fd3-dbf5-418d-b4fe-5f69de8d6bbc
- date added to LUP
- 2025-05-28 12:51:35
- date last changed
- 2025-06-02 16:46:19
@article{32238fd3-dbf5-418d-b4fe-5f69de8d6bbc,
abstract = {{<p>New mapping and laboratory studies of the impactites at the Gardnos impact structure (Norway) show a variety of impact-deformed rocks. Our mapping and petrographic analyses have subdivided these breccias into three distinct categories: (a) melt-bearing sueivitic breccias, melt-bearing polymict breccias; (b) melt-free, polymict lithic impact breccias; and (c) monomict lithic impact breccias. This illustrates the dynamic nature of crater floor processes where mixing occurs in multiple ways. Feldspar grains exhibit evidence of intense shear, micro-faults, and alternate twin deformation in feldspar. We also observe the development of additional, amphibole-like planar elements (or cleavage) in biotite. Melt-bearing breccias contain carbon concentrations up to an order of magnitude higher than the target rocks. Unusual textures of carbon petrographically associated with shock and post-shock features in feldspars suggest significant postimpact hydrothermal mobilization of carbon within these rocks. Gardnos, therefore, represents an important terrestrial analog for understanding a suite of impact- and postimpact geologic processes.</p>}},
author = {{Jaret, Steven J. and Hyde, William R. and Shteynman, Leah}},
issn = {{1086-9379}},
language = {{eng}},
publisher = {{Wiley-Blackwell}},
series = {{Meteoritics and Planetary Science}},
title = {{Petrography and field relationships of impact lithologies at the Gardnos impact structure, Norway}},
url = {{http://dx.doi.org/10.1111/maps.14354}},
doi = {{10.1111/maps.14354}},
year = {{2025}},
}