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Has the tectonic regime of the Baltic Shield always remained the same?

Lindh, Anders LU (2022) In GFF 144(1). p.59-70
Abstract

Recent theories on the growth of continental crust stress its formation in pre-Archean and Archean times with minor additions at later times. The Earth has gone through a unidirectional evolution including surface changes, the genesis of life and an important loss of energy. The energy loss drives tectonic processes, but at a rate declining with available energy and thus with time. Semiquantitative modelling of energy-changes and transport indicates important differences between today’s Earth and the Paleoproterozoic Earth. Actualistic but non-uniformitarian arguments suggest that principal tectonic processes have changed over time. The Baltic Shield displays a fundamental difference in conditions between the c. 0.9 Ga high-pressure... (More)

Recent theories on the growth of continental crust stress its formation in pre-Archean and Archean times with minor additions at later times. The Earth has gone through a unidirectional evolution including surface changes, the genesis of life and an important loss of energy. The energy loss drives tectonic processes, but at a rate declining with available energy and thus with time. Semiquantitative modelling of energy-changes and transport indicates important differences between today’s Earth and the Paleoproterozoic Earth. Actualistic but non-uniformitarian arguments suggest that principal tectonic processes have changed over time. The Baltic Shield displays a fundamental difference in conditions between the c. 0.9 Ga high-pressure metamorphism including the occurrence of eclogite in the western Sveconorwegian Orogen and c. 2 Ga low-pressure metamorphism in the eastern Svecokarelian Orogen. This suggests that modern platetectonic processes were operative at c. 0.9 Ga but leaves the question whether it was active during the Svecokarelian orogeny open. The lack of eclogite in the Svecokarelian Orogen is explained with a change with time of the geotherm slope. The occurrence of two generations of granitic rocks of different compositions in the Svecokarelian is easily explained by an increased mantle heat flow in a stratified continental crust. In contrast to calc-alkaline platetectonic compositions, alkali-calcic rocks occur in a quarter-circle around the Svecokarelian core. The question arises whether modern plate-processes successively replaced proto-plate processes during Paleo- and Mesoproterozoic times.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Baltic Shield, crustal growth, energy loss, Mylonite Zone, proto-plate processes, Svecokarelian, Sveconorwegian, Temperature modelling
in
GFF
volume
144
issue
1
pages
59 - 70
publisher
Taylor & Francis
external identifiers
  • scopus:85124951158
ISSN
1103-5897
DOI
10.1080/11035897.2021.1993453
language
English
LU publication?
yes
id
17c3c6f4-fdf4-45fd-ad66-d5357a04b4a0
date added to LUP
2022-05-19 13:18:45
date last changed
2022-06-29 12:59:32
@article{17c3c6f4-fdf4-45fd-ad66-d5357a04b4a0,
  abstract     = {{<p>Recent theories on the growth of continental crust stress its formation in pre-Archean and Archean times with minor additions at later times. The Earth has gone through a unidirectional evolution including surface changes, the genesis of life and an important loss of energy. The energy loss drives tectonic processes, but at a rate declining with available energy and thus with time. Semiquantitative modelling of energy-changes and transport indicates important differences between today’s Earth and the Paleoproterozoic Earth. Actualistic but non-uniformitarian arguments suggest that principal tectonic processes have changed over time. The Baltic Shield displays a fundamental difference in conditions between the c. 0.9 Ga high-pressure metamorphism including the occurrence of eclogite in the western Sveconorwegian Orogen and c. 2 Ga low-pressure metamorphism in the eastern Svecokarelian Orogen. This suggests that modern platetectonic processes were operative at c. 0.9 Ga but leaves the question whether it was active during the Svecokarelian orogeny open. The lack of eclogite in the Svecokarelian Orogen is explained with a change with time of the geotherm slope. The occurrence of two generations of granitic rocks of different compositions in the Svecokarelian is easily explained by an increased mantle heat flow in a stratified continental crust. In contrast to calc-alkaline platetectonic compositions, alkali-calcic rocks occur in a quarter-circle around the Svecokarelian core. The question arises whether modern plate-processes successively replaced proto-plate processes during Paleo- and Mesoproterozoic times.</p>}},
  author       = {{Lindh, Anders}},
  issn         = {{1103-5897}},
  keywords     = {{Baltic Shield; crustal growth; energy loss; Mylonite Zone; proto-plate processes; Svecokarelian; Sveconorwegian; Temperature modelling}},
  language     = {{eng}},
  month        = {{02}},
  number       = {{1}},
  pages        = {{59--70}},
  publisher    = {{Taylor & Francis}},
  series       = {{GFF}},
  title        = {{Has the tectonic regime of the Baltic Shield always remained the same?}},
  url          = {{http://dx.doi.org/10.1080/11035897.2021.1993453}},
  doi          = {{10.1080/11035897.2021.1993453}},
  volume       = {{144}},
  year         = {{2022}},
}