U-Pb ages of granitoid rocks in the northwestern Makkovik Province, Labrador: evidence for 175 million years of episodic synorogenic and postorogenic plutonism
New UPb zircon, titanite, and monazite ages reported here, along with existing age data, demonstrate that granitoid bodies in the northwestern segment of the Paleoproterozoic Makkovik Province, Labrador, are of three distinct ages. The redefined Island Harbour Bay plutonic suite consists of varied...
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crcansciencepubl:10.1139/e00-085 2024-03-03T08:46:25+00:00 U-Pb ages of granitoid rocks in the northwestern Makkovik Province, Labrador: evidence for 175 million years of episodic synorogenic and postorogenic plutonism Ketchum, John WF Barr, Sandra M Culshaw, Nicholas G White, Chris E 2001 http://dx.doi.org/10.1139/e00-085 http://www.nrcresearchpress.com/doi/pdf/10.1139/e00-085 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 38, issue 3, page 359-372 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 2001 crcansciencepubl https://doi.org/10.1139/e00-085 2024-02-07T10:53:39Z New UPb zircon, titanite, and monazite ages reported here, along with existing age data, demonstrate that granitoid bodies in the northwestern segment of the Paleoproterozoic Makkovik Province, Labrador, are of three distinct ages. The redefined Island Harbour Bay plutonic suite consists of varied dioritic to granitic units that were syntectonically emplaced into Archean crust of the Kaipokok domain between ca. 1895 Ma and 1870 ± 2 Ma. This plutonism occurred during the early stages of the Makkovikian Orogeny in an obliquely convergent, Andean continental margin setting. The Hares Islands and Drunken Harbour granites form smaller, discrete plutons that were emplaced in or adjacent to the Island Harbour Bay plutonic suite at 1805 ± 5 Ma and 1791 ± 2 Ma, respectively, during dextral strike-slip deformation that accompanied accretion of an outboard juvenile terrane. Magmatic activity during this period was preferentially sited along active structural zones, but also occurred outside of these zones. The undeformed Blacklers Bight A-type granite was emplaced in the Kaipokok domain at 1716 ± 1 Ma, late in the development of the orogen. A-type granites of this age form a significant component of the southeastern Makkovik Province, and their generation is linked to mafic underplating and heterogeneous regional extension. The new age data support the conclusion of earlier workers that crustal growth via synorogenic and postorogenic plutonism was episodic, and allow, along with field and geochemical data, inferences to be made regarding the tectonic setting of individual plutonic events. Article in Journal/Newspaper Makkovik Canadian Science Publishing Makkovik ENVELOPE(-59.178,-59.178,55.087,55.087) Harbour Bay ENVELOPE(-76.881,-76.881,69.618,69.618) Island Harbour ENVELOPE(70.067,70.067,-49.483,-49.483) Canadian Journal of Earth Sciences 38 3 359 372 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
General Earth and Planetary Sciences |
spellingShingle |
General Earth and Planetary Sciences Ketchum, John WF Barr, Sandra M Culshaw, Nicholas G White, Chris E U-Pb ages of granitoid rocks in the northwestern Makkovik Province, Labrador: evidence for 175 million years of episodic synorogenic and postorogenic plutonism |
topic_facet |
General Earth and Planetary Sciences |
description |
New UPb zircon, titanite, and monazite ages reported here, along with existing age data, demonstrate that granitoid bodies in the northwestern segment of the Paleoproterozoic Makkovik Province, Labrador, are of three distinct ages. The redefined Island Harbour Bay plutonic suite consists of varied dioritic to granitic units that were syntectonically emplaced into Archean crust of the Kaipokok domain between ca. 1895 Ma and 1870 ± 2 Ma. This plutonism occurred during the early stages of the Makkovikian Orogeny in an obliquely convergent, Andean continental margin setting. The Hares Islands and Drunken Harbour granites form smaller, discrete plutons that were emplaced in or adjacent to the Island Harbour Bay plutonic suite at 1805 ± 5 Ma and 1791 ± 2 Ma, respectively, during dextral strike-slip deformation that accompanied accretion of an outboard juvenile terrane. Magmatic activity during this period was preferentially sited along active structural zones, but also occurred outside of these zones. The undeformed Blacklers Bight A-type granite was emplaced in the Kaipokok domain at 1716 ± 1 Ma, late in the development of the orogen. A-type granites of this age form a significant component of the southeastern Makkovik Province, and their generation is linked to mafic underplating and heterogeneous regional extension. The new age data support the conclusion of earlier workers that crustal growth via synorogenic and postorogenic plutonism was episodic, and allow, along with field and geochemical data, inferences to be made regarding the tectonic setting of individual plutonic events. |
format |
Article in Journal/Newspaper |
author |
Ketchum, John WF Barr, Sandra M Culshaw, Nicholas G White, Chris E |
author_facet |
Ketchum, John WF Barr, Sandra M Culshaw, Nicholas G White, Chris E |
author_sort |
Ketchum, John WF |
title |
U-Pb ages of granitoid rocks in the northwestern Makkovik Province, Labrador: evidence for 175 million years of episodic synorogenic and postorogenic plutonism |
title_short |
U-Pb ages of granitoid rocks in the northwestern Makkovik Province, Labrador: evidence for 175 million years of episodic synorogenic and postorogenic plutonism |
title_full |
U-Pb ages of granitoid rocks in the northwestern Makkovik Province, Labrador: evidence for 175 million years of episodic synorogenic and postorogenic plutonism |
title_fullStr |
U-Pb ages of granitoid rocks in the northwestern Makkovik Province, Labrador: evidence for 175 million years of episodic synorogenic and postorogenic plutonism |
title_full_unstemmed |
U-Pb ages of granitoid rocks in the northwestern Makkovik Province, Labrador: evidence for 175 million years of episodic synorogenic and postorogenic plutonism |
title_sort |
u-pb ages of granitoid rocks in the northwestern makkovik province, labrador: evidence for 175 million years of episodic synorogenic and postorogenic plutonism |
publisher |
Canadian Science Publishing |
publishDate |
2001 |
url |
http://dx.doi.org/10.1139/e00-085 http://www.nrcresearchpress.com/doi/pdf/10.1139/e00-085 |
long_lat |
ENVELOPE(-59.178,-59.178,55.087,55.087) ENVELOPE(-76.881,-76.881,69.618,69.618) ENVELOPE(70.067,70.067,-49.483,-49.483) |
geographic |
Makkovik Harbour Bay Island Harbour |
geographic_facet |
Makkovik Harbour Bay Island Harbour |
genre |
Makkovik |
genre_facet |
Makkovik |
op_source |
Canadian Journal of Earth Sciences volume 38, issue 3, page 359-372 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e00-085 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
38 |
container_issue |
3 |
container_start_page |
359 |
op_container_end_page |
372 |
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1792502430807621632 |