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The Finnefjeld domain, Maniitsoq structure, West Greenland: Differential rheological features and mechanical homogenisation in response to impacting?

Garde, Adam A.; Dyck, Brendan; Esbensen, Kim H.; Johansson, Leif LU and Möller, Charlotte LU (2014) In Precambrian Research 255. p.791-808
Abstract
The 35 by 50 km large, Mesoarchaean Finnefjeld domain near Maniitsoq in the North Atlantic craton of southern West Greenland constitutes the central part of the previously proposed, deeply eroded Maniitsoq impact structure with an age of 3.0 Ga. The Finnefjeld domain is an exceedingly homogeneous, quartzo-feldspathic rock mass which superficially appears to be a late-orogenic, deep-crustal, intrusive granitoid pluton, and which was described as such for decades. However, new observations confirm and qualify the first observations from 1962 of these rocks as 'cataclastic'. The Finnefjeld domain is characterised by a highly unusual, mixed rheological behaviour. Plagioclase displays brittle behaviour with cataclasis, quartz was ductilely... (More)
The 35 by 50 km large, Mesoarchaean Finnefjeld domain near Maniitsoq in the North Atlantic craton of southern West Greenland constitutes the central part of the previously proposed, deeply eroded Maniitsoq impact structure with an age of 3.0 Ga. The Finnefjeld domain is an exceedingly homogeneous, quartzo-feldspathic rock mass which superficially appears to be a late-orogenic, deep-crustal, intrusive granitoid pluton, and which was described as such for decades. However, new observations confirm and qualify the first observations from 1962 of these rocks as 'cataclastic'. The Finnefjeld domain is characterised by a highly unusual, mixed rheological behaviour. Plagioclase displays brittle behaviour with cataclasis, quartz was ductilely deformed, and K-feldspar was melted. The deformation and homogenisation of the Finnefjeld domain was caused by an intense event of heating and deformation, which was coseismic in nature and comprised numerous increments of pure shear strain. This type of intense, brittle, regional deformation and concomitant direct mineral melting in the deep crust is unknown from endogenic orogenic events and is ascribed to deep-crustal effects of impacting. (C) 2014 Elsevier B.V. All rights reserved. (Less)
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Contribution to journal
publication status
published
subject
keywords
Mixed theological behaviour, Maniitsoq impact structure, Cataclasis, Direct mineral melting
in
Precambrian Research
volume
255
pages
791 - 808
publisher
Elsevier
external identifiers
  • wos:000347660600003
  • scopus:84919385297
ISSN
0301-9268
DOI
10.1016/j.precamres.2014.06.022
language
English
LU publication?
yes
id
7022b2b2-0a6b-48cb-a90d-5855286a2fdf (old id 5195118)
date added to LUP
2015-03-27 11:20:24
date last changed
2017-02-19 03:06:28
@article{7022b2b2-0a6b-48cb-a90d-5855286a2fdf,
  abstract     = {The 35 by 50 km large, Mesoarchaean Finnefjeld domain near Maniitsoq in the North Atlantic craton of southern West Greenland constitutes the central part of the previously proposed, deeply eroded Maniitsoq impact structure with an age of 3.0 Ga. The Finnefjeld domain is an exceedingly homogeneous, quartzo-feldspathic rock mass which superficially appears to be a late-orogenic, deep-crustal, intrusive granitoid pluton, and which was described as such for decades. However, new observations confirm and qualify the first observations from 1962 of these rocks as 'cataclastic'. The Finnefjeld domain is characterised by a highly unusual, mixed rheological behaviour. Plagioclase displays brittle behaviour with cataclasis, quartz was ductilely deformed, and K-feldspar was melted. The deformation and homogenisation of the Finnefjeld domain was caused by an intense event of heating and deformation, which was coseismic in nature and comprised numerous increments of pure shear strain. This type of intense, brittle, regional deformation and concomitant direct mineral melting in the deep crust is unknown from endogenic orogenic events and is ascribed to deep-crustal effects of impacting. (C) 2014 Elsevier B.V. All rights reserved.},
  author       = {Garde, Adam A. and Dyck, Brendan and Esbensen, Kim H. and Johansson, Leif and Möller, Charlotte},
  issn         = {0301-9268},
  keyword      = {Mixed theological behaviour,Maniitsoq impact structure,Cataclasis,Direct mineral melting},
  language     = {eng},
  pages        = {791--808},
  publisher    = {Elsevier},
  series       = {Precambrian Research},
  title        = {The Finnefjeld domain, Maniitsoq structure, West Greenland: Differential rheological features and mechanical homogenisation in response to impacting?},
  url          = {http://dx.doi.org/10.1016/j.precamres.2014.06.022},
  volume       = {255},
  year         = {2014},
}