Initial tectonothermal evolution within the Scandinavian Caledonide Accretionary Prism: constraints from 40 Ar/ 39 Ar mineral ages within the Seve Nappe Complex, Sarek Mountains, Sweden
In the Caledonide orogen of northern Sweden, the Seve Nappe Complex is dominated by rift facies sedimentary and mafic rocks derived from the Late Proterozoic Baltoscandian miogeocline and offshore‐continent–Iapetus transition. Metamorphic breaks and structural inversions characterize the nappe compl...
Published in: | Journal of Metamorphic Geology |
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Online Access: | http://dx.doi.org/10.1111/j.1525-1314.1991.tb00515.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1525-1314.1991.tb00515.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1525-1314.1991.tb00515.x |
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crwiley:10.1111/j.1525-1314.1991.tb00515.x 2024-06-02T08:12:14+00:00 Initial tectonothermal evolution within the Scandinavian Caledonide Accretionary Prism: constraints from 40 Ar/ 39 Ar mineral ages within the Seve Nappe Complex, Sarek Mountains, Sweden DALLMEYER, R. D. ANDRÉASSON, P. G. SVENNINGSEN, O. 1991 http://dx.doi.org/10.1111/j.1525-1314.1991.tb00515.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1525-1314.1991.tb00515.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1525-1314.1991.tb00515.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Journal of Metamorphic Geology volume 9, issue 2, page 203-218 ISSN 0263-4929 1525-1314 journal-article 1991 crwiley https://doi.org/10.1111/j.1525-1314.1991.tb00515.x 2024-05-03T11:39:02Z In the Caledonide orogen of northern Sweden, the Seve Nappe Complex is dominated by rift facies sedimentary and mafic rocks derived from the Late Proterozoic Baltoscandian miogeocline and offshore‐continent–Iapetus transition. Metamorphic breaks and structural inversions characterize the nappe complex. Within the Sarek Mountains, the Sarektjåkkå Nappe is composed of c. 600‐Ma‐old dolerites with subordinate screens of sedimentary rocks. These lithological elements preserve parageneses which record contact metamorphism at shallow crustal levels. The Sarektjåkkå Nappe is situated between eclogite‐bearing nappes (Mikka and Tsäkkok nappes) which underwent high‐ P metamorphism at c. 500 Ma during westward subduction of the Baltoscandian margin. 40 Ar/ 39 Ar mineral ages of c. 520–500 Ma are recorded by hornblende within variably foliated amphibolite derived from mafic dyke protoliths within the Sarektjåkkå Nappe. Plateau ages of 500 Ma are displayed by muscovite within the basal thrust of the nappe and are consistent with metamorphic evidence which indicates that the nappe escaped crustal depression as a result of detachment at an early stage of subduction. Cooling ages recorded by hornblende from variably retrogressed eclogites in the entire region are in the range of c. 510–490 Ma and suggest that imbrication of the subducting miogeocline was followed by differential exhumation of the various imbricate sheets. Hornblende cooling ages of 470–460 Ma are recorded from massive dyke protoliths within the Sarektjåkkå Nappe. These are similar to ages reported from the Seve Nappe Complex in the central Scandinavian Caledonides. Probably these date imbrication and uplift related to Early Ordovician arrival of outboard terranes (e.g. island‐arc sequences represented by structurally lower horizons of the Köli Nappes). Metamorphic contrasts and the distinct grouping of mineral cooling ages suggest that the various Seve structural units are themselves internally imbricated, and were individually tectonically uplifted through ... Article in Journal/Newspaper Northern Sweden Wiley Online Library Sarek ENVELOPE(17.500,17.500,67.350,67.350) Sarektjåkkå ENVELOPE(17.721,17.721,67.433,67.433) Tsäkkok ENVELOPE(16.783,16.783,67.067,67.067) Journal of Metamorphic Geology 9 2 203 218 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
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In the Caledonide orogen of northern Sweden, the Seve Nappe Complex is dominated by rift facies sedimentary and mafic rocks derived from the Late Proterozoic Baltoscandian miogeocline and offshore‐continent–Iapetus transition. Metamorphic breaks and structural inversions characterize the nappe complex. Within the Sarek Mountains, the Sarektjåkkå Nappe is composed of c. 600‐Ma‐old dolerites with subordinate screens of sedimentary rocks. These lithological elements preserve parageneses which record contact metamorphism at shallow crustal levels. The Sarektjåkkå Nappe is situated between eclogite‐bearing nappes (Mikka and Tsäkkok nappes) which underwent high‐ P metamorphism at c. 500 Ma during westward subduction of the Baltoscandian margin. 40 Ar/ 39 Ar mineral ages of c. 520–500 Ma are recorded by hornblende within variably foliated amphibolite derived from mafic dyke protoliths within the Sarektjåkkå Nappe. Plateau ages of 500 Ma are displayed by muscovite within the basal thrust of the nappe and are consistent with metamorphic evidence which indicates that the nappe escaped crustal depression as a result of detachment at an early stage of subduction. Cooling ages recorded by hornblende from variably retrogressed eclogites in the entire region are in the range of c. 510–490 Ma and suggest that imbrication of the subducting miogeocline was followed by differential exhumation of the various imbricate sheets. Hornblende cooling ages of 470–460 Ma are recorded from massive dyke protoliths within the Sarektjåkkå Nappe. These are similar to ages reported from the Seve Nappe Complex in the central Scandinavian Caledonides. Probably these date imbrication and uplift related to Early Ordovician arrival of outboard terranes (e.g. island‐arc sequences represented by structurally lower horizons of the Köli Nappes). Metamorphic contrasts and the distinct grouping of mineral cooling ages suggest that the various Seve structural units are themselves internally imbricated, and were individually tectonically uplifted through ... |
format |
Article in Journal/Newspaper |
author |
DALLMEYER, R. D. ANDRÉASSON, P. G. SVENNINGSEN, O. |
spellingShingle |
DALLMEYER, R. D. ANDRÉASSON, P. G. SVENNINGSEN, O. Initial tectonothermal evolution within the Scandinavian Caledonide Accretionary Prism: constraints from 40 Ar/ 39 Ar mineral ages within the Seve Nappe Complex, Sarek Mountains, Sweden |
author_facet |
DALLMEYER, R. D. ANDRÉASSON, P. G. SVENNINGSEN, O. |
author_sort |
DALLMEYER, R. D. |
title |
Initial tectonothermal evolution within the Scandinavian Caledonide Accretionary Prism: constraints from 40 Ar/ 39 Ar mineral ages within the Seve Nappe Complex, Sarek Mountains, Sweden |
title_short |
Initial tectonothermal evolution within the Scandinavian Caledonide Accretionary Prism: constraints from 40 Ar/ 39 Ar mineral ages within the Seve Nappe Complex, Sarek Mountains, Sweden |
title_full |
Initial tectonothermal evolution within the Scandinavian Caledonide Accretionary Prism: constraints from 40 Ar/ 39 Ar mineral ages within the Seve Nappe Complex, Sarek Mountains, Sweden |
title_fullStr |
Initial tectonothermal evolution within the Scandinavian Caledonide Accretionary Prism: constraints from 40 Ar/ 39 Ar mineral ages within the Seve Nappe Complex, Sarek Mountains, Sweden |
title_full_unstemmed |
Initial tectonothermal evolution within the Scandinavian Caledonide Accretionary Prism: constraints from 40 Ar/ 39 Ar mineral ages within the Seve Nappe Complex, Sarek Mountains, Sweden |
title_sort |
initial tectonothermal evolution within the scandinavian caledonide accretionary prism: constraints from 40 ar/ 39 ar mineral ages within the seve nappe complex, sarek mountains, sweden |
publisher |
Wiley |
publishDate |
1991 |
url |
http://dx.doi.org/10.1111/j.1525-1314.1991.tb00515.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1525-1314.1991.tb00515.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1525-1314.1991.tb00515.x |
long_lat |
ENVELOPE(17.500,17.500,67.350,67.350) ENVELOPE(17.721,17.721,67.433,67.433) ENVELOPE(16.783,16.783,67.067,67.067) |
geographic |
Sarek Sarektjåkkå Tsäkkok |
geographic_facet |
Sarek Sarektjåkkå Tsäkkok |
genre |
Northern Sweden |
genre_facet |
Northern Sweden |
op_source |
Journal of Metamorphic Geology volume 9, issue 2, page 203-218 ISSN 0263-4929 1525-1314 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1525-1314.1991.tb00515.x |
container_title |
Journal of Metamorphic Geology |
container_volume |
9 |
container_issue |
2 |
container_start_page |
203 |
op_container_end_page |
218 |
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1800758609839128576 |