View in EDS

The timing of stabilisation and the exhumation rate for ultra-high pressure rocks in the Western Gneiss Region of Norway.

Saved in:
Bibliographic Details
Title: The timing of stabilisation and the exhumation rate for ultra-high pressure rocks in the Western Gneiss Region of Norway.
Authors: Carswell, D. A.1, Brueckner, H. K.2,3, Cuthbert, S. J.4, Mehta, K.2, O'Brien, P. J.5
Source: Journal of Metamorphic Geology. Aug2003, Vol. 21 Issue 6, p601-612. 12p.
Subjects: Rocks, Petrology, Geology, Environmental sciences
Geographic Terms: Norway
Abstract: Abstract New petrographic evidence and a review of the latest radiometric age data are taken to indicate that formation of the ultra-high pressure (UHP) eclogites within the Western Gneiss Region of Norway probably occurred within the 400–410 Ma time frame. Thus, this event took place significantly later than the previous, widely accepted age of c. 425 Ma for the timing of the high pressure metamorphism in this part of the Scandinavian Caledonides. Garnet growth under UHP (coesite-stable) conditions is recognised as a discrete, younger event following on from earlier garnet formed under firstly amphibolite facies then quartz-stable, eclogite facies conditions. Currently, the best constrained and most precise age, specifically for UHP mineral growth, is the 402 ± 2 Ma U–Pb age for metamorphic zircon (some of which retain coesite inclusions) from the Hareidland eclogite. Exhumation must have followed shortly thereafter and, based on synoptic pressure–temperature and depth–time curves, must have been very fast. Our data and those of others indicate an initial fast exhumation to about 35 km depth by about 395 Ma at a mean rate of about 10 mm a-1 . This rapid exhumation rate may have been driven by the appreciable residual buoyancy of the deeply subducted continental crustal slab due to incomplete eclogitization of the dominant Proterozoic orthogneisses during the short-lived UHP event. Subsequent exhumation to 8–10 km depth by about 375 Ma occurred at a much slower mean rate of about 1.3 mm a-1 with the late-stage extensional collapse of the Caledonian orogen playing an increasingly important role, especially in the final unroofing of the Western Gneiss Region with some remarkably preserved UHP rocks. [ABSTRACT FROM AUTHOR]
Copyright of Journal of Metamorphic Geology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
FullText Text:
  Availability: 0
Header DbId: egs
DbLabel: Engineering Source
An: 10390267
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: The timing of stabilisation and the exhumation rate for ultra-high pressure rocks in the Western Gneiss Region of Norway.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Carswell%2C+D%2E+A%2E%22">Carswell, D. A.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Brueckner%2C+H%2E+K%2E%22">Brueckner, H. K.</searchLink><relatesTo>2,3</relatesTo><br /><searchLink fieldCode="AR" term="%22Cuthbert%2C+S%2E+J%2E%22">Cuthbert, S. J.</searchLink><relatesTo>4</relatesTo><br /><searchLink fieldCode="AR" term="%22Mehta%2C+K%2E%22">Mehta, K.</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22O'Brien%2C+P%2E+J%2E%22">O'Brien, P. J.</searchLink><relatesTo>5</relatesTo>
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Journal+of+Metamorphic+Geology%22">Journal of Metamorphic Geology</searchLink>. Aug2003, Vol. 21 Issue 6, p601-612. 12p.
– Name: Subject
  Label: Subjects
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Rocks%22">Rocks</searchLink><br /><searchLink fieldCode="DE" term="%22Petrology%22">Petrology</searchLink><br /><searchLink fieldCode="DE" term="%22Geology%22">Geology</searchLink><br /><searchLink fieldCode="DE" term="%22Environmental+sciences%22">Environmental sciences</searchLink>
– Name: SubjectGeographic
  Label: Geographic Terms
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Norway%22">Norway</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: Abstract New petrographic evidence and a review of the latest radiometric age data are taken to indicate that formation of the ultra-high pressure (UHP) eclogites within the Western Gneiss Region of Norway probably occurred within the 400–410 Ma time frame. Thus, this event took place significantly later than the previous, widely accepted age of c. 425 Ma for the timing of the high pressure metamorphism in this part of the Scandinavian Caledonides. Garnet growth under UHP (coesite-stable) conditions is recognised as a discrete, younger event following on from earlier garnet formed under firstly amphibolite facies then quartz-stable, eclogite facies conditions. Currently, the best constrained and most precise age, specifically for UHP mineral growth, is the 402 ± 2 Ma U–Pb age for metamorphic zircon (some of which retain coesite inclusions) from the Hareidland eclogite. Exhumation must have followed shortly thereafter and, based on synoptic pressure–temperature and depth–time curves, must have been very fast. Our data and those of others indicate an initial fast exhumation to about 35 km depth by about 395 Ma at a mean rate of about 10 mm a-1 . This rapid exhumation rate may have been driven by the appreciable residual buoyancy of the deeply subducted continental crustal slab due to incomplete eclogitization of the dominant Proterozoic orthogneisses during the short-lived UHP event. Subsequent exhumation to 8–10 km depth by about 375 Ma occurred at a much slower mean rate of about 1.3 mm a-1 with the late-stage extensional collapse of the Caledonian orogen playing an increasingly important role, especially in the final unroofing of the Western Gneiss Region with some remarkably preserved UHP rocks. [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: <i>Copyright of Journal of Metamorphic Geology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=10390267
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1046/j.1525-1314.2003.00467.x
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 12
        StartPage: 601
    Subjects:
      – SubjectFull: Rocks
        Type: general
      – SubjectFull: Petrology
        Type: general
      – SubjectFull: Geology
        Type: general
      – SubjectFull: Environmental sciences
        Type: general
      – SubjectFull: Norway
        Type: general
    Titles:
      – TitleFull: The timing of stabilisation and the exhumation rate for ultra-high pressure rocks in the Western Gneiss Region of Norway.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Carswell, D. A.
      – PersonEntity:
          Name:
            NameFull: Brueckner, H. K.
      – PersonEntity:
          Name:
            NameFull: Cuthbert, S. J.
      – PersonEntity:
          Name:
            NameFull: Mehta, K.
      – PersonEntity:
          Name:
            NameFull: O'Brien, P. J.
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 08
              Text: Aug2003
              Type: published
              Y: 2003
          Identifiers:
            – Type: issn-print
              Value: 02634929
          Numbering:
            – Type: volume
              Value: 21
            – Type: issue
              Value: 6
          Titles:
            – TitleFull: Journal of Metamorphic Geology
              Type: main
ResultId 1