Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Transition from fracturing to viscous flow in granulite facies perthitic feldspar (Lofoten, Norway)
Show others and affiliations
2013 (English)In: Journal of Structural Geology, ISSN 0191-8141, E-ISSN 1873-1201, Vol. 48, p. 95-112Article in journal (Refereed) Published
Abstract [en]

Recrystallization of perthites in granulite fades (T = 700-730 degrees C, P = 0.65-0.8 GPa) shear zones in mangerite-charnockite rocks from Lofoten (Norway) is localized along intracrystalline bands parallel to fractures. Fracturing preferentially occurred along the cleavage planes (010) and (001). EBSD analysis of perthite porphyroclasts indicates a very low degree of internal misorientation (within 5 degrees) and the lack of recovery features. Recrystallized grains show coarsening with increasing width of the bands, and chemical changes with respect to the host grains. Crystallographic orientation of the new grains does not show a host-control relation to the parent perthite grains. In summary, the microstructure and CPO data consistently indicate intragranular redystallization by nucleation and growth from fractured grains. Perthite porphyroclasts are surrounded by a matrix of recrystallized plagioclase + K-feldspar +/- amphibole +/- biotite. There is extensive evidence of syndeformational nucleation of new phases and of phase boundary migration in the matrix, with plagioclase grains forming bulges and protrusions towards K-feldspar. The spatial distribution of K-feldspar and plagioclase in the recrystallized matrix is characterized by the predominance of phase boundaries over grain boundaries. All these observations are consistent with diffusion creep as the dominant deformation mechanism in the matrix, associated with grain boundary sliding. Accordingly, recrystallized plagioclase and K-feldspar show a very weak crystallographic preferred orientation, which is interpreted in terms of oriented growth during diffusion creep. Fracturing of perthites promoted extensive grain size reduction, recrystallization, fluid infiltration, and operation of grain-size sensitive creep, resulting in strain localization.

Place, publisher, year, edition, pages
2013. Vol. 48, p. 95-112
Keywords [en]
Fracturing, Recrystallization, Perthites, Diffusion creep, Spatial distribution of phases, Electron backscatter diffraction (EBSD), Deformation of the lower crust
National Category
Geosciences, Multidisciplinary
Identifiers
URN: urn:nbn:se:su:diva-88989DOI: 10.1016/j.jsg.2012.12.004ISI: 000315843400009OAI: oai:DiVA.org:su-88989DiVA, id: diva2:615439
Note

AuthorCount:5;

Available from: 2013-04-10 Created: 2013-04-08 Last updated: 2017-12-06Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text
By organisation
Department of Geological Sciences
In the same journal
Journal of Structural Geology
Geosciences, Multidisciplinary

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 37 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf