The Mings Bight Ophiolite Complex, Newfoundland: Appalachian oceanic crust and mantle
The Mings Bight Ophiolite Complex, of probable early Ordovician age, is disposed in four major thrust sheets with an eastward vergence at the northern end of the Baie Verte Lineament. This narrow ophiolitic belt, and (to the south) an adjacent zone of early Devonian volcanic rocks and sediments, wer...
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crcansciencepubl:10.1139/e78-084 2023-12-17T10:27:39+01:00 The Mings Bight Ophiolite Complex, Newfoundland: Appalachian oceanic crust and mantle Kidd, W. S. F. Dewey, John F. Bird, John M. 1978 http://dx.doi.org/10.1139/e78-084 http://www.nrcresearchpress.com/doi/pdf/10.1139/e78-084 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 15, issue 5, page 781-804 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 1978 crcansciencepubl https://doi.org/10.1139/e78-084 2023-11-19T13:39:35Z The Mings Bight Ophiolite Complex, of probable early Ordovician age, is disposed in four major thrust sheets with an eastward vergence at the northern end of the Baie Verte Lineament. This narrow ophiolitic belt, and (to the south) an adjacent zone of early Devonian volcanic rocks and sediments, were affected by a strong Acadian (Middle Devonian?) deformation between more resistant blocks consisting mainly of rocks that were deformed and regionally metamorphosed, prior to the development of the ophiolites and overlying mafic sediments and volcanic rocks, probably in Late Cambrian to earliest Ordovician. The ophiolite sequence and conformably overlying sedimentary and volcanic sequence define an overturned synclinal structure with an eastward vergence; the three western thrust sheets contain an inverted sequence, the eastern sheet is upright. The thick mafic volcaniclastic and pillow lava sequence overlying the ophiolite complex suggests that the ophiolite complex was generated as the the floor of a small rear-arc or intra-arc basin. The ophiolite complex, although dissected by faults, consists of an ordered sequence from non-cumulate tectonite harzburgite through cumulate ultramafic rocks, gabbro and sheeted dike complex to pillow lavas. The continuous, coastal exposures show the relationships between the lithologies of the ophiolite complex unusually clearly, and these are described in some detail. In particular, the relationships between the sheeted dikes and both the homogeneous upper gabbro and the pillow lavas, and the intrusive complexities and the high-temperature deformation in the layered gabbros and ultramafics, are very clearly displayed. An ocean floor fault containing diapiric serpentinite is preserved in one thrust sheet. Two new formations are proposed, for the mafic volcaniclastic sediments (Big Head Formation) and for the overlying pillow lavas (Barry–Cunningham Formation) above the ophiolite complex. Article in Journal/Newspaper Baie Verte Newfoundland Canadian Science Publishing (via Crossref) Verte ENVELOPE(141.192,141.192,-66.740,-66.740) Baie Verte ENVELOPE(-56.182,-56.182,49.933,49.933) Big Head ENVELOPE(-55.081,-55.081,49.517,49.517) Canadian Journal of Earth Sciences 15 5 781 804 |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
General Earth and Planetary Sciences |
spellingShingle |
General Earth and Planetary Sciences Kidd, W. S. F. Dewey, John F. Bird, John M. The Mings Bight Ophiolite Complex, Newfoundland: Appalachian oceanic crust and mantle |
topic_facet |
General Earth and Planetary Sciences |
description |
The Mings Bight Ophiolite Complex, of probable early Ordovician age, is disposed in four major thrust sheets with an eastward vergence at the northern end of the Baie Verte Lineament. This narrow ophiolitic belt, and (to the south) an adjacent zone of early Devonian volcanic rocks and sediments, were affected by a strong Acadian (Middle Devonian?) deformation between more resistant blocks consisting mainly of rocks that were deformed and regionally metamorphosed, prior to the development of the ophiolites and overlying mafic sediments and volcanic rocks, probably in Late Cambrian to earliest Ordovician. The ophiolite sequence and conformably overlying sedimentary and volcanic sequence define an overturned synclinal structure with an eastward vergence; the three western thrust sheets contain an inverted sequence, the eastern sheet is upright. The thick mafic volcaniclastic and pillow lava sequence overlying the ophiolite complex suggests that the ophiolite complex was generated as the the floor of a small rear-arc or intra-arc basin. The ophiolite complex, although dissected by faults, consists of an ordered sequence from non-cumulate tectonite harzburgite through cumulate ultramafic rocks, gabbro and sheeted dike complex to pillow lavas. The continuous, coastal exposures show the relationships between the lithologies of the ophiolite complex unusually clearly, and these are described in some detail. In particular, the relationships between the sheeted dikes and both the homogeneous upper gabbro and the pillow lavas, and the intrusive complexities and the high-temperature deformation in the layered gabbros and ultramafics, are very clearly displayed. An ocean floor fault containing diapiric serpentinite is preserved in one thrust sheet. Two new formations are proposed, for the mafic volcaniclastic sediments (Big Head Formation) and for the overlying pillow lavas (Barry–Cunningham Formation) above the ophiolite complex. |
format |
Article in Journal/Newspaper |
author |
Kidd, W. S. F. Dewey, John F. Bird, John M. |
author_facet |
Kidd, W. S. F. Dewey, John F. Bird, John M. |
author_sort |
Kidd, W. S. F. |
title |
The Mings Bight Ophiolite Complex, Newfoundland: Appalachian oceanic crust and mantle |
title_short |
The Mings Bight Ophiolite Complex, Newfoundland: Appalachian oceanic crust and mantle |
title_full |
The Mings Bight Ophiolite Complex, Newfoundland: Appalachian oceanic crust and mantle |
title_fullStr |
The Mings Bight Ophiolite Complex, Newfoundland: Appalachian oceanic crust and mantle |
title_full_unstemmed |
The Mings Bight Ophiolite Complex, Newfoundland: Appalachian oceanic crust and mantle |
title_sort |
mings bight ophiolite complex, newfoundland: appalachian oceanic crust and mantle |
publisher |
Canadian Science Publishing |
publishDate |
1978 |
url |
http://dx.doi.org/10.1139/e78-084 http://www.nrcresearchpress.com/doi/pdf/10.1139/e78-084 |
long_lat |
ENVELOPE(141.192,141.192,-66.740,-66.740) ENVELOPE(-56.182,-56.182,49.933,49.933) ENVELOPE(-55.081,-55.081,49.517,49.517) |
geographic |
Verte Baie Verte Big Head |
geographic_facet |
Verte Baie Verte Big Head |
genre |
Baie Verte Newfoundland |
genre_facet |
Baie Verte Newfoundland |
op_source |
Canadian Journal of Earth Sciences volume 15, issue 5, page 781-804 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e78-084 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
15 |
container_issue |
5 |
container_start_page |
781 |
op_container_end_page |
804 |
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1785579559600521216 |