Peak to post-peak thermal history of the Saglek Block of Labrador: A multiphase and multi-instrumental approach to geochronology

The Saglek Block of coastal Labrador forms the western margin of the North Atlantic Craton, where Archean gneisses and granulites have been reworked during the Paleoproterozoic. Previous work has established that the block is a composite of Eoarchean to Mesoarchean protoliths metamorphosed to upper...

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Main Authors: Kusiak, M., Dunkley, Daniel, Whitehouse, M., Wilde, Simon, Salacinska, A., Konecný, P., Szopa, K., Gaweda, A., Chew, D.
Format: Journal Article
Published: Elsevier Science BV 2017
Online Access:http://hdl.handle.net/20.500.11937/60715
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author Kusiak, M.
Dunkley, Daniel
Whitehouse, M.
Wilde, Simon
Salacinska, A.
Konecný, P.
Szopa, K.
Gaweda, A.
Chew, D.
author_facet Kusiak, M.
Dunkley, Daniel
Whitehouse, M.
Wilde, Simon
Salacinska, A.
Konecný, P.
Szopa, K.
Gaweda, A.
Chew, D.
author_sort Kusiak, M.
building Curtin Institutional Repository
collection Online Access
description The Saglek Block of coastal Labrador forms the western margin of the North Atlantic Craton, where Archean gneisses and granulites have been reworked during the Paleoproterozoic. Previous work has established that the block is a composite of Eoarchean to Mesoarchean protoliths metamorphosed to upper amphibolite and granulite facies at around 2.8-2.7. Ga. New in-situ microbeam dating of accessory minerals in granoblastic gneisses reveals a complex peak to post-peak thermal history. Zircon growth at ca. 3.7-3.6. Ga provides the age of formation of the tonalitic protoliths to the gneisses. Further zircon growth in syn-tectonic granitic gneiss and monazite growth in a variety of orthogneisses confirm peak metamorphic conditions at ca. 2.7. Ga, but also reveal high-temperature conditions at ca. 2.6. Ga and 2.5. Ga. The former is interpreted as the waning stages of the 2.7. Ga granulite event, whereas the latter is associated with a younger phase of granitic magmatism. In addition, apatite ages of ca. 2.2. Ga may represent either cooling associated with the 2.5. Ga event or a previously unrecognized greenschist-facies metamorphism event that predates the Torngat Orogeny.
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institution Curtin University Malaysia
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last_indexed 2025-11-14T10:18:49Z
publishDate 2017
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spelling curtin-20.500.11937-607152018-07-31T04:38:24Z Peak to post-peak thermal history of the Saglek Block of Labrador: A multiphase and multi-instrumental approach to geochronology Kusiak, M. Dunkley, Daniel Whitehouse, M. Wilde, Simon Salacinska, A. Konecný, P. Szopa, K. Gaweda, A. Chew, D. The Saglek Block of coastal Labrador forms the western margin of the North Atlantic Craton, where Archean gneisses and granulites have been reworked during the Paleoproterozoic. Previous work has established that the block is a composite of Eoarchean to Mesoarchean protoliths metamorphosed to upper amphibolite and granulite facies at around 2.8-2.7. Ga. New in-situ microbeam dating of accessory minerals in granoblastic gneisses reveals a complex peak to post-peak thermal history. Zircon growth at ca. 3.7-3.6. Ga provides the age of formation of the tonalitic protoliths to the gneisses. Further zircon growth in syn-tectonic granitic gneiss and monazite growth in a variety of orthogneisses confirm peak metamorphic conditions at ca. 2.7. Ga, but also reveal high-temperature conditions at ca. 2.6. Ga and 2.5. Ga. The former is interpreted as the waning stages of the 2.7. Ga granulite event, whereas the latter is associated with a younger phase of granitic magmatism. In addition, apatite ages of ca. 2.2. Ga may represent either cooling associated with the 2.5. Ga event or a previously unrecognized greenschist-facies metamorphism event that predates the Torngat Orogeny. 2017 Journal Article http://hdl.handle.net/20.500.11937/60715 10.1016/j.chemgeo.2017.10.033 Elsevier Science BV restricted
spellingShingle Kusiak, M.
Dunkley, Daniel
Whitehouse, M.
Wilde, Simon
Salacinska, A.
Konecný, P.
Szopa, K.
Gaweda, A.
Chew, D.
Peak to post-peak thermal history of the Saglek Block of Labrador: A multiphase and multi-instrumental approach to geochronology
title Peak to post-peak thermal history of the Saglek Block of Labrador: A multiphase and multi-instrumental approach to geochronology
title_full Peak to post-peak thermal history of the Saglek Block of Labrador: A multiphase and multi-instrumental approach to geochronology
title_fullStr Peak to post-peak thermal history of the Saglek Block of Labrador: A multiphase and multi-instrumental approach to geochronology
title_full_unstemmed Peak to post-peak thermal history of the Saglek Block of Labrador: A multiphase and multi-instrumental approach to geochronology
title_short Peak to post-peak thermal history of the Saglek Block of Labrador: A multiphase and multi-instrumental approach to geochronology
title_sort peak to post-peak thermal history of the saglek block of labrador: a multiphase and multi-instrumental approach to geochronology
url http://hdl.handle.net/20.500.11937/60715