The southeastern Churchill Province: synthesis of a Paleoproterozoic transpressional orogen

The Paleoproterozoic southeastern Churchill Province (SECP) is located in the northeastern Canadian Shield of Labrador and Quebec. The SECP formed through the oblique collisions of the Archean Nain and Superior cratons with a third intervening Archean block, the core zone. The belt has a tripartite...

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Published in:Canadian Journal of Earth Sciences
Main Authors: Wardle, Richard J, James, Donald T, Scott, David J, Hall, Jeremy
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 2002
Subjects:
Online Access:http://dx.doi.org/10.1139/e02-004
http://www.nrcresearchpress.com/doi/pdf/10.1139/e02-004
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spelling crcansciencepubl:10.1139/e02-004 2024-09-15T18:19:02+00:00 The southeastern Churchill Province: synthesis of a Paleoproterozoic transpressional orogen Wardle, Richard J James, Donald T Scott, David J Hall, Jeremy 2002 http://dx.doi.org/10.1139/e02-004 http://www.nrcresearchpress.com/doi/pdf/10.1139/e02-004 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 39, issue 5, page 639-663 ISSN 0008-4077 1480-3313 journal-article 2002 crcansciencepubl https://doi.org/10.1139/e02-004 2024-09-05T04:11:17Z The Paleoproterozoic southeastern Churchill Province (SECP) is located in the northeastern Canadian Shield of Labrador and Quebec. The SECP formed through the oblique collisions of the Archean Nain and Superior cratons with a third intervening Archean block, the core zone. The belt has a tripartite structure, comprising the Torngat Orogen (TO) formed by Nain craton – core zone collision in the east, the core zone in the centre, and the New Quebec Orogen (NQO) formed by Superior craton – core zone collision in the west. The SECP thus records transpressional development on the flanks of the Superior and Nain cratons as they indented northwards to form the larger Trans-Hudson – Nagssugtoqidian orogenic belt to the north. Principal stages of tectonic development were (1) 2.2–2.1 Ga crustal rifting of Nain and Superior cratons; (2) ca. 1.9 Ga subduction under eastern Nain craton; (3) ca. 1.87–1.85 Ga collision of Nain craton and core zone to form the TO; (4) 1.845–1.820 Ga sinistral transpression in the TO, and subduction under the western core zone; and (5) 1.82–1.77 Ga collision of Superior craton and core zone to form the NQO, in association with dextral transpression. Crustal-scale cross sections of the SECP have been developed from reflection and refraction seismic data. The western part of the NQO is dominantly west-vergent and associated with an imbricate thick-skinned thrust stack that ramps from the base of the crust. The core zone is characterized by a 35–40 km thick crust and pervasive east-dipping fabrics related to westerly thrusting. The TO is a narrow, doubly vergent belt, associated with a 48 km thick crust that forms a crustal root with a Moho relief of 12 km. The root is interpreted to result from attempted subduction of the core zone under the Nain craton, possibly as a result of mid-crustal wedging by the Nain craton. The TO was the site of intense convergence that resulted in excision of juvenile crust, possibly including tectonic removal of the axial magmatic arc. As a result, the middle to ... Article in Journal/Newspaper Nain Canadian Science Publishing Canadian Journal of Earth Sciences 39 5 639 663
institution Open Polar
collection Canadian Science Publishing
op_collection_id crcansciencepubl
language English
description The Paleoproterozoic southeastern Churchill Province (SECP) is located in the northeastern Canadian Shield of Labrador and Quebec. The SECP formed through the oblique collisions of the Archean Nain and Superior cratons with a third intervening Archean block, the core zone. The belt has a tripartite structure, comprising the Torngat Orogen (TO) formed by Nain craton – core zone collision in the east, the core zone in the centre, and the New Quebec Orogen (NQO) formed by Superior craton – core zone collision in the west. The SECP thus records transpressional development on the flanks of the Superior and Nain cratons as they indented northwards to form the larger Trans-Hudson – Nagssugtoqidian orogenic belt to the north. Principal stages of tectonic development were (1) 2.2–2.1 Ga crustal rifting of Nain and Superior cratons; (2) ca. 1.9 Ga subduction under eastern Nain craton; (3) ca. 1.87–1.85 Ga collision of Nain craton and core zone to form the TO; (4) 1.845–1.820 Ga sinistral transpression in the TO, and subduction under the western core zone; and (5) 1.82–1.77 Ga collision of Superior craton and core zone to form the NQO, in association with dextral transpression. Crustal-scale cross sections of the SECP have been developed from reflection and refraction seismic data. The western part of the NQO is dominantly west-vergent and associated with an imbricate thick-skinned thrust stack that ramps from the base of the crust. The core zone is characterized by a 35–40 km thick crust and pervasive east-dipping fabrics related to westerly thrusting. The TO is a narrow, doubly vergent belt, associated with a 48 km thick crust that forms a crustal root with a Moho relief of 12 km. The root is interpreted to result from attempted subduction of the core zone under the Nain craton, possibly as a result of mid-crustal wedging by the Nain craton. The TO was the site of intense convergence that resulted in excision of juvenile crust, possibly including tectonic removal of the axial magmatic arc. As a result, the middle to ...
format Article in Journal/Newspaper
author Wardle, Richard J
James, Donald T
Scott, David J
Hall, Jeremy
spellingShingle Wardle, Richard J
James, Donald T
Scott, David J
Hall, Jeremy
The southeastern Churchill Province: synthesis of a Paleoproterozoic transpressional orogen
author_facet Wardle, Richard J
James, Donald T
Scott, David J
Hall, Jeremy
author_sort Wardle, Richard J
title The southeastern Churchill Province: synthesis of a Paleoproterozoic transpressional orogen
title_short The southeastern Churchill Province: synthesis of a Paleoproterozoic transpressional orogen
title_full The southeastern Churchill Province: synthesis of a Paleoproterozoic transpressional orogen
title_fullStr The southeastern Churchill Province: synthesis of a Paleoproterozoic transpressional orogen
title_full_unstemmed The southeastern Churchill Province: synthesis of a Paleoproterozoic transpressional orogen
title_sort southeastern churchill province: synthesis of a paleoproterozoic transpressional orogen
publisher Canadian Science Publishing
publishDate 2002
url http://dx.doi.org/10.1139/e02-004
http://www.nrcresearchpress.com/doi/pdf/10.1139/e02-004
genre Nain
genre_facet Nain
op_source Canadian Journal of Earth Sciences
volume 39, issue 5, page 639-663
ISSN 0008-4077 1480-3313
op_rights http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining
op_doi https://doi.org/10.1139/e02-004
container_title Canadian Journal of Earth Sciences
container_volume 39
container_issue 5
container_start_page 639
op_container_end_page 663
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