Palaeomagnetism of the Skinner Cove Formation of Western Newfoundland and the birth of the Iapetus Ocean
The 550 Ma Skinner Cove Formation is a structural unit within the Humber Arm Allochthon of western Newfoundland, occurring as an alkali volcanic suite affected only by zeolite facies metamorphism. At 10 sites from its flows and dykes a magnetite-borne, stable characteristic 'A' remanence d...
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Memorial University of Newfoundland
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ftmemorialuniv:oai:research.library.mun.ca:6554 2023-10-01T03:57:34+02:00 Palaeomagnetism of the Skinner Cove Formation of Western Newfoundland and the birth of the Iapetus Ocean McCausland, Philip John Albert 1998 application/pdf https://research.library.mun.ca/6554/ https://research.library.mun.ca/6554/1/PhilipJohnAlbertMcCausland.pdf https://research.library.mun.ca/6554/3/PhilipJohnAlbertMcCausland.pdf en eng Memorial University of Newfoundland https://research.library.mun.ca/6554/1/PhilipJohnAlbertMcCausland.pdf https://research.library.mun.ca/6554/3/PhilipJohnAlbertMcCausland.pdf McCausland, Philip John Albert <https://research.library.mun.ca/view/creator_az/McCausland=3APhilip_John_Albert=3A=3A.html> (1998) Palaeomagnetism of the Skinner Cove Formation of Western Newfoundland and the birth of the Iapetus Ocean. Masters thesis, Memorial University of Newfoundland. thesis_license Thesis NonPeerReviewed 1998 ftmemorialuniv 2023-09-03T06:45:57Z The 550 Ma Skinner Cove Formation is a structural unit within the Humber Arm Allochthon of western Newfoundland, occurring as an alkali volcanic suite affected only by zeolite facies metamorphism. At 10 sites from its flows and dykes a magnetite-borne, stable characteristic 'A' remanence direction (tilt-corrected mean D=144°, I=31.5°; α₉₅=10.8°, k=21.1) is recognized and shown to be a primary thermal remanence by an intraformational conglomerate test. The palaeolatitude calculated for the Skinner Cove Formation from its ten 'A' site virtual geomagnetic poles is 18.6°S ±9°. -- An original relation between the Skinner Cove Formation and the Iapetan margin of Laurentia is suggested by several lines of evidence: As a structural slice it occupies a lower, less transported position in the Humber Arm Allochthon, implying an original adjacency to underlying slices of Laurentian margin sediments. The Skinner Cove volcanics have a within plate trace element geochemistry with enriched light rare earth elements (LREE), shared with other alkali volcanics of the northeastern Appalachians Humber Zone. Also, the ~550 Ma Skinner Cove volcanics are of similar age to alkali magmatic activity of Laurentia's Iapetan margin, marked by the ~554 Ma Tibbit Hill metavolcanics of Quebec and the ~555 Ma Lady Slipper Pluton of west Newfoundland. Hence, the 18.6°S palaeolatitude of the Skinner Cove Formation constrains Laurentia to an equatorial position at ~550 Ma. -- Comparison with other palaeomagnetically determined high southerly palaeolatitudes for ~570 Ma implies a large rapid northward drift of ~34 cm/yr for Laurentia during the latest Neoproterozoic. The start of Laurentia's rapid northward movement at ~570 Ma may mark the beginning of Iapetus sea-floor spreading, consistent with Laurentian geological data if thermally-delayed subsidence of the Laurentian margin is assumed. Further well-constrained palaeomagnetic results of ~580 ~550 Ma age from Laurentia and especially its suspected conjugate margins Amazonia and Rio de la Plata ... Thesis Newfoundland Memorial University of Newfoundland: Research Repository Skinner Cove ENVELOPE(-54.398,-54.398,49.667,49.667) |
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Open Polar |
collection |
Memorial University of Newfoundland: Research Repository |
op_collection_id |
ftmemorialuniv |
language |
English |
description |
The 550 Ma Skinner Cove Formation is a structural unit within the Humber Arm Allochthon of western Newfoundland, occurring as an alkali volcanic suite affected only by zeolite facies metamorphism. At 10 sites from its flows and dykes a magnetite-borne, stable characteristic 'A' remanence direction (tilt-corrected mean D=144°, I=31.5°; α₉₅=10.8°, k=21.1) is recognized and shown to be a primary thermal remanence by an intraformational conglomerate test. The palaeolatitude calculated for the Skinner Cove Formation from its ten 'A' site virtual geomagnetic poles is 18.6°S ±9°. -- An original relation between the Skinner Cove Formation and the Iapetan margin of Laurentia is suggested by several lines of evidence: As a structural slice it occupies a lower, less transported position in the Humber Arm Allochthon, implying an original adjacency to underlying slices of Laurentian margin sediments. The Skinner Cove volcanics have a within plate trace element geochemistry with enriched light rare earth elements (LREE), shared with other alkali volcanics of the northeastern Appalachians Humber Zone. Also, the ~550 Ma Skinner Cove volcanics are of similar age to alkali magmatic activity of Laurentia's Iapetan margin, marked by the ~554 Ma Tibbit Hill metavolcanics of Quebec and the ~555 Ma Lady Slipper Pluton of west Newfoundland. Hence, the 18.6°S palaeolatitude of the Skinner Cove Formation constrains Laurentia to an equatorial position at ~550 Ma. -- Comparison with other palaeomagnetically determined high southerly palaeolatitudes for ~570 Ma implies a large rapid northward drift of ~34 cm/yr for Laurentia during the latest Neoproterozoic. The start of Laurentia's rapid northward movement at ~570 Ma may mark the beginning of Iapetus sea-floor spreading, consistent with Laurentian geological data if thermally-delayed subsidence of the Laurentian margin is assumed. Further well-constrained palaeomagnetic results of ~580 ~550 Ma age from Laurentia and especially its suspected conjugate margins Amazonia and Rio de la Plata ... |
format |
Thesis |
author |
McCausland, Philip John Albert |
spellingShingle |
McCausland, Philip John Albert Palaeomagnetism of the Skinner Cove Formation of Western Newfoundland and the birth of the Iapetus Ocean |
author_facet |
McCausland, Philip John Albert |
author_sort |
McCausland, Philip John Albert |
title |
Palaeomagnetism of the Skinner Cove Formation of Western Newfoundland and the birth of the Iapetus Ocean |
title_short |
Palaeomagnetism of the Skinner Cove Formation of Western Newfoundland and the birth of the Iapetus Ocean |
title_full |
Palaeomagnetism of the Skinner Cove Formation of Western Newfoundland and the birth of the Iapetus Ocean |
title_fullStr |
Palaeomagnetism of the Skinner Cove Formation of Western Newfoundland and the birth of the Iapetus Ocean |
title_full_unstemmed |
Palaeomagnetism of the Skinner Cove Formation of Western Newfoundland and the birth of the Iapetus Ocean |
title_sort |
palaeomagnetism of the skinner cove formation of western newfoundland and the birth of the iapetus ocean |
publisher |
Memorial University of Newfoundland |
publishDate |
1998 |
url |
https://research.library.mun.ca/6554/ https://research.library.mun.ca/6554/1/PhilipJohnAlbertMcCausland.pdf https://research.library.mun.ca/6554/3/PhilipJohnAlbertMcCausland.pdf |
long_lat |
ENVELOPE(-54.398,-54.398,49.667,49.667) |
geographic |
Skinner Cove |
geographic_facet |
Skinner Cove |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_relation |
https://research.library.mun.ca/6554/1/PhilipJohnAlbertMcCausland.pdf https://research.library.mun.ca/6554/3/PhilipJohnAlbertMcCausland.pdf McCausland, Philip John Albert <https://research.library.mun.ca/view/creator_az/McCausland=3APhilip_John_Albert=3A=3A.html> (1998) Palaeomagnetism of the Skinner Cove Formation of Western Newfoundland and the birth of the Iapetus Ocean. Masters thesis, Memorial University of Newfoundland. |
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thesis_license |
_version_ |
1778529109172813824 |