Characterization of sills associated with the U reflection on the Newfoundland margin : evidence for widespread early post-rift magmatism on a magma-poor rifted margin
Author Posting. © The Authors, 2010. This article is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Geophysical Journal International 182 (2010): 113-136, doi:10.1111/j.1365-246X.2010.04635.x. Drilling during ODP L...
Published in: | Geophysical Journal International |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
John Wiley & Sons
2010
|
Subjects: | |
Online Access: | https://hdl.handle.net/1912/3698 |
id |
ftwhoas:oai:darchive.mblwhoilibrary.org:1912/3698 |
---|---|
record_format |
openpolar |
spelling |
ftwhoas:oai:darchive.mblwhoilibrary.org:1912/3698 2023-05-15T17:21:35+02:00 Characterization of sills associated with the U reflection on the Newfoundland margin : evidence for widespread early post-rift magmatism on a magma-poor rifted margin Peron-Pinvidic, Gwenn Shillington, Donna J. Tucholke, Brian E. 2010-05-25 application/pdf https://hdl.handle.net/1912/3698 en_US eng John Wiley & Sons https://doi.org/10.1111/j.1365-246X.2010.04635.x Geophysical Journal International 182 (2010): 113-136 https://hdl.handle.net/1912/3698 doi:10.1111/j.1365-246X.2010.04635.x Geophysical Journal International 182 (2010): 113-136 doi:10.1111/j.1365-246X.2010.04635.x Ocean drilling Continental margins: divergent Hotspots Atlantic Ocean Article 2010 ftwhoas https://doi.org/10.1111/j.1365-246X.2010.04635.x 2022-05-28T22:58:02Z Author Posting. © The Authors, 2010. This article is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Geophysical Journal International 182 (2010): 113-136, doi:10.1111/j.1365-246X.2010.04635.x. Drilling during ODP Leg 210 penetrated two post-rift sills (dated as ∼105.3 and ∼97.8 Ma) in the deep sediments overlying basement of the continent–ocean transition zone on the magma-poor Newfoundland margin. The sill emplacement post-dated the onset of seafloor spreading by at least 7–15 Myr. The shallower of the two sills coincides with the high-amplitude U reflection observed throughout the deep Newfoundland Basin, and strong reflectivity in the sub-U sequence suggests that a number of other sills are present there. In this paper, we use multichannel seismic reflection data and synthetic seismograms to investigate the nature, magnitude and extent of this post-rift magmatism in the deep basin. Features observed in seismic profiles that we attribute to sill injection include high-amplitude reflections with geometries characteristic of intrusions such as step-like aspect; abrupt endings, disruptions and junctions of reflections; finger-like forms; differential compaction around possible loci of magma injection and disruption of overlying sediments by apparent fluid venting. Interpreted sills occur only over transitional basement that probably consists of a mixture of serpentinized peridotite and highly thinned continental crust, and they cover an area of ∼80 000 km2. From analysis of synthetic seismograms, we estimate that sill intrusions may comprise ∼26 per cent of the sub-U high-reflectivity sequence, which yields a crude estimate of ∼5800 km3 for the total volume of sills emplaced by post-rift magmatism. This is significant for a margin usually described as 'non-volcanic'. We discuss competing hypotheses about the source of the magmatism, which is still uncertain. G. Peron-Pinvidic's post-doctoral research at the University of ... Article in Journal/Newspaper Newfoundland Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Geophysical Journal International no no |
institution |
Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
Ocean drilling Continental margins: divergent Hotspots Atlantic Ocean |
spellingShingle |
Ocean drilling Continental margins: divergent Hotspots Atlantic Ocean Peron-Pinvidic, Gwenn Shillington, Donna J. Tucholke, Brian E. Characterization of sills associated with the U reflection on the Newfoundland margin : evidence for widespread early post-rift magmatism on a magma-poor rifted margin |
topic_facet |
Ocean drilling Continental margins: divergent Hotspots Atlantic Ocean |
description |
Author Posting. © The Authors, 2010. This article is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Geophysical Journal International 182 (2010): 113-136, doi:10.1111/j.1365-246X.2010.04635.x. Drilling during ODP Leg 210 penetrated two post-rift sills (dated as ∼105.3 and ∼97.8 Ma) in the deep sediments overlying basement of the continent–ocean transition zone on the magma-poor Newfoundland margin. The sill emplacement post-dated the onset of seafloor spreading by at least 7–15 Myr. The shallower of the two sills coincides with the high-amplitude U reflection observed throughout the deep Newfoundland Basin, and strong reflectivity in the sub-U sequence suggests that a number of other sills are present there. In this paper, we use multichannel seismic reflection data and synthetic seismograms to investigate the nature, magnitude and extent of this post-rift magmatism in the deep basin. Features observed in seismic profiles that we attribute to sill injection include high-amplitude reflections with geometries characteristic of intrusions such as step-like aspect; abrupt endings, disruptions and junctions of reflections; finger-like forms; differential compaction around possible loci of magma injection and disruption of overlying sediments by apparent fluid venting. Interpreted sills occur only over transitional basement that probably consists of a mixture of serpentinized peridotite and highly thinned continental crust, and they cover an area of ∼80 000 km2. From analysis of synthetic seismograms, we estimate that sill intrusions may comprise ∼26 per cent of the sub-U high-reflectivity sequence, which yields a crude estimate of ∼5800 km3 for the total volume of sills emplaced by post-rift magmatism. This is significant for a margin usually described as 'non-volcanic'. We discuss competing hypotheses about the source of the magmatism, which is still uncertain. G. Peron-Pinvidic's post-doctoral research at the University of ... |
format |
Article in Journal/Newspaper |
author |
Peron-Pinvidic, Gwenn Shillington, Donna J. Tucholke, Brian E. |
author_facet |
Peron-Pinvidic, Gwenn Shillington, Donna J. Tucholke, Brian E. |
author_sort |
Peron-Pinvidic, Gwenn |
title |
Characterization of sills associated with the U reflection on the Newfoundland margin : evidence for widespread early post-rift magmatism on a magma-poor rifted margin |
title_short |
Characterization of sills associated with the U reflection on the Newfoundland margin : evidence for widespread early post-rift magmatism on a magma-poor rifted margin |
title_full |
Characterization of sills associated with the U reflection on the Newfoundland margin : evidence for widespread early post-rift magmatism on a magma-poor rifted margin |
title_fullStr |
Characterization of sills associated with the U reflection on the Newfoundland margin : evidence for widespread early post-rift magmatism on a magma-poor rifted margin |
title_full_unstemmed |
Characterization of sills associated with the U reflection on the Newfoundland margin : evidence for widespread early post-rift magmatism on a magma-poor rifted margin |
title_sort |
characterization of sills associated with the u reflection on the newfoundland margin : evidence for widespread early post-rift magmatism on a magma-poor rifted margin |
publisher |
John Wiley & Sons |
publishDate |
2010 |
url |
https://hdl.handle.net/1912/3698 |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
Geophysical Journal International 182 (2010): 113-136 doi:10.1111/j.1365-246X.2010.04635.x |
op_relation |
https://doi.org/10.1111/j.1365-246X.2010.04635.x Geophysical Journal International 182 (2010): 113-136 https://hdl.handle.net/1912/3698 doi:10.1111/j.1365-246X.2010.04635.x |
op_doi |
https://doi.org/10.1111/j.1365-246X.2010.04635.x |
container_title |
Geophysical Journal International |
container_start_page |
no |
op_container_end_page |
no |
_version_ |
1766106572896862208 |