Metamorphism of the Mullerneset Formation, St. Jonsfjorden, Svalbard
The metamorphism of upper greenschist facies metasediments exposed in the extreme southwestern portion of St. Jonsjorden, Svalbard, is described. The rocks form part of the Miillerneset Formation of the late Precambrian age Kongsvegen Group and constitute a portion of the central-western Spitsbergen...
Published in: | Polar Research |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Norwegian Polar Institute
1985
|
Subjects: | |
Online Access: | https://polarresearch.net/index.php/polar/article/view/2514 https://doi.org/10.3402/polar.v3i1.6941 |
id |
ftjpolarres:oai:journals.openacademia.net:article/2514 |
---|---|
record_format |
openpolar |
spelling |
ftjpolarres:oai:journals.openacademia.net:article/2514 2023-05-15T18:02:40+02:00 Metamorphism of the Mullerneset Formation, St. Jonsfjorden, Svalbard Ague, Jay James Morris, Alan Paul 1985-01-02 application/pdf https://polarresearch.net/index.php/polar/article/view/2514 https://doi.org/10.3402/polar.v3i1.6941 eng eng Norwegian Polar Institute https://polarresearch.net/index.php/polar/article/view/2514/5765 https://polarresearch.net/index.php/polar/article/view/2514 doi:10.3402/polar.v3i1.6941 Copyright (c) 2018 Polar Research Polar Research; Vol. 3 No. 1 (1985); 93-106 1751-8369 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 1985 ftjpolarres https://doi.org/10.3402/polar.v3i1.6941 2021-11-11T19:12:57Z The metamorphism of upper greenschist facies metasediments exposed in the extreme southwestern portion of St. Jonsjorden, Svalbard, is described. The rocks form part of the Miillerneset Formation of the late Precambrian age Kongsvegen Group and constitute a portion of the central-western Spitsbergen Caledonides. Four deformations (DI-D~) and two metamorphic episodes (MI and Mz) have affected the rocks of the Miillerneset area. MI was a prograde event which was initiated prior to the onset of the D1 and continued through this deformation. Pre-DI metamorphism reached biotite grade whereas garnet grade was attained syn-DI. MZ was a lower-middle greenschist facies metamorphism associated with Dz. The results of quantitative geothermometry in the pelitic rocks show that peak MI metamorphic temperatures decrease southwards across the field area from about 540°C to 510°C. Geobarometry and estimates of depth of burial indicate that MI pressures were in the range of 5-7kb. The data are consistent with geothermal gradients in the range of 21 f 4"C/km to 24 f S"C/km. MZ metamorphic conditions are not precisely determinable but temperatures and pressures were probably less than those attained during MI. It is suggested that the rocks of central-western Spitsbergen were originally deposited in an aulacogen before the initiation of Caledonian diastrophism. Article in Journal/Newspaper Polar Research Svalbard Spitsbergen Polar Research (E-Journal) Kongsvegen ENVELOPE(12.657,12.657,78.854,78.854) Mullerneset ENVELOPE(13.967,13.967,79.800,79.800) Svalbard Polar Research 3 1 93 106 |
institution |
Open Polar |
collection |
Polar Research (E-Journal) |
op_collection_id |
ftjpolarres |
language |
English |
description |
The metamorphism of upper greenschist facies metasediments exposed in the extreme southwestern portion of St. Jonsjorden, Svalbard, is described. The rocks form part of the Miillerneset Formation of the late Precambrian age Kongsvegen Group and constitute a portion of the central-western Spitsbergen Caledonides. Four deformations (DI-D~) and two metamorphic episodes (MI and Mz) have affected the rocks of the Miillerneset area. MI was a prograde event which was initiated prior to the onset of the D1 and continued through this deformation. Pre-DI metamorphism reached biotite grade whereas garnet grade was attained syn-DI. MZ was a lower-middle greenschist facies metamorphism associated with Dz. The results of quantitative geothermometry in the pelitic rocks show that peak MI metamorphic temperatures decrease southwards across the field area from about 540°C to 510°C. Geobarometry and estimates of depth of burial indicate that MI pressures were in the range of 5-7kb. The data are consistent with geothermal gradients in the range of 21 f 4"C/km to 24 f S"C/km. MZ metamorphic conditions are not precisely determinable but temperatures and pressures were probably less than those attained during MI. It is suggested that the rocks of central-western Spitsbergen were originally deposited in an aulacogen before the initiation of Caledonian diastrophism. |
format |
Article in Journal/Newspaper |
author |
Ague, Jay James Morris, Alan Paul |
spellingShingle |
Ague, Jay James Morris, Alan Paul Metamorphism of the Mullerneset Formation, St. Jonsfjorden, Svalbard |
author_facet |
Ague, Jay James Morris, Alan Paul |
author_sort |
Ague, Jay James |
title |
Metamorphism of the Mullerneset Formation, St. Jonsfjorden, Svalbard |
title_short |
Metamorphism of the Mullerneset Formation, St. Jonsfjorden, Svalbard |
title_full |
Metamorphism of the Mullerneset Formation, St. Jonsfjorden, Svalbard |
title_fullStr |
Metamorphism of the Mullerneset Formation, St. Jonsfjorden, Svalbard |
title_full_unstemmed |
Metamorphism of the Mullerneset Formation, St. Jonsfjorden, Svalbard |
title_sort |
metamorphism of the mullerneset formation, st. jonsfjorden, svalbard |
publisher |
Norwegian Polar Institute |
publishDate |
1985 |
url |
https://polarresearch.net/index.php/polar/article/view/2514 https://doi.org/10.3402/polar.v3i1.6941 |
long_lat |
ENVELOPE(12.657,12.657,78.854,78.854) ENVELOPE(13.967,13.967,79.800,79.800) |
geographic |
Kongsvegen Mullerneset Svalbard |
geographic_facet |
Kongsvegen Mullerneset Svalbard |
genre |
Polar Research Svalbard Spitsbergen |
genre_facet |
Polar Research Svalbard Spitsbergen |
op_source |
Polar Research; Vol. 3 No. 1 (1985); 93-106 1751-8369 |
op_relation |
https://polarresearch.net/index.php/polar/article/view/2514/5765 https://polarresearch.net/index.php/polar/article/view/2514 doi:10.3402/polar.v3i1.6941 |
op_rights |
Copyright (c) 2018 Polar Research |
op_doi |
https://doi.org/10.3402/polar.v3i1.6941 |
container_title |
Polar Research |
container_volume |
3 |
container_issue |
1 |
container_start_page |
93 |
op_container_end_page |
106 |
_version_ |
1766173105748705280 |