Uncertainties in break-up markers along the Iberia–Newfoundland margins illustrated by new seismic data
Plate tectonic modellers often rely on the identifi- cation of “break-up” markers to reconstruct the early stages of continental separation. Along the Iberian-Newfoundland margin, so-called break-up markers include interpretations of old magnetic anomalies from the M series, as well as the “J anomal...
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Copernicus Publications
2020
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Online Access: | https://epic.awi.de/id/eprint/51558/ https://epic.awi.de/id/eprint/51558/1/Causer_etal_2020_SolidEarth_IberiaNewf.pdf https://hdl.handle.net/10013/epic.d67549f3-bb5f-4381-abc1-629f7d689f13 https://hdl.handle.net/ |
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ftawi:oai:epic.awi.de:51558 2023-05-15T17:19:34+02:00 Uncertainties in break-up markers along the Iberia–Newfoundland margins illustrated by new seismic data Causer, Annabel Pérez-Díaz, Lucía Adam, Jürgen Eagles, Graeme 2020 application/pdf https://epic.awi.de/id/eprint/51558/ https://epic.awi.de/id/eprint/51558/1/Causer_etal_2020_SolidEarth_IberiaNewf.pdf https://hdl.handle.net/10013/epic.d67549f3-bb5f-4381-abc1-629f7d689f13 https://hdl.handle.net/ unknown Copernicus Publications https://epic.awi.de/id/eprint/51558/1/Causer_etal_2020_SolidEarth_IberiaNewf.pdf https://hdl.handle.net/ Causer, A. , Pérez-Díaz, L. , Adam, J. and Eagles, G. orcid:0000-0001-5325-0810 (2020) Uncertainties in break-up markers along the Iberia–Newfoundland margins illustrated by new seismic data , Solid Earth, 11 , pp. 397-417 . doi:10.5194/se-11-397-2020 <https://doi.org/10.5194/se-11-397-2020> , hdl:10013/epic.d67549f3-bb5f-4381-abc1-629f7d689f13 EPIC3Solid Earth, Copernicus Publications, 11, pp. 397-417 Article isiRev 2020 ftawi https://doi.org/10.5194/se-11-397-2020 2021-12-24T15:45:22Z Plate tectonic modellers often rely on the identifi- cation of “break-up” markers to reconstruct the early stages of continental separation. Along the Iberian-Newfoundland margin, so-called break-up markers include interpretations of old magnetic anomalies from the M series, as well as the “J anomaly”. These have been used as the basis for plate tectonic reconstructions are based on the concept that these anomalies pinpoint the location of first oceanic lithosphere. However, uncertainties in the location and interpretation of break-up markers, as well as the difficulty in dating them precisely, has led to plate models that differ in both the tim- ing and relative palaeo-positions of Iberia and Newfoundland during separation. We use newly available seismic data from the Southern Newfoundland Basin (SNB) to assess the suitability of com- monly used break-up markers along the Newfoundland mar- gin for plate kinematic reconstructions. Our data show that basement associated with the younger M-series magnetic anomalies is comprised of exhumed mantle and magmatic additions and most likely represents transitional domains and not true oceanic lithosphere. Because rifting propagated northward, we argue that M-series anomaly identifications further north, although in a region not imaged by our seis- mic, are also unlikely to be diagnostic of true oceanic crust beneath the SNB. Similarly, our data also allow us to show that the high amplitude of the J Anomaly is associated with a zone of exhumed mantle punctuated by significant volcanic additions and at times characterized by interbedded volcanics and sediments. Magmatic activity in the SNB at a time coin- ciding with M4 (128 Ma) and the presence of SDR packages onlapping onto a basement fault suggest that, at this time, plate divergence was still being accommodated by tectonic faulting. We illustrate the differences in the relative positions of Iberia and Newfoundland across published plate reconstruc- tions and discuss how these are a direct consequence of the uncertainties introduced into the modelling procedure by the use of extended continental margin data (dubious magnetic anomaly identifications, break-up unconformity interpreta- tions). We conclude that a different approach is needed for constraining plate kinematics of the Iberian plate pre-M0 times. Article in Journal/Newspaper Newfoundland Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Solid Earth 11 2 397 417 |
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Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
Plate tectonic modellers often rely on the identifi- cation of “break-up” markers to reconstruct the early stages of continental separation. Along the Iberian-Newfoundland margin, so-called break-up markers include interpretations of old magnetic anomalies from the M series, as well as the “J anomaly”. These have been used as the basis for plate tectonic reconstructions are based on the concept that these anomalies pinpoint the location of first oceanic lithosphere. However, uncertainties in the location and interpretation of break-up markers, as well as the difficulty in dating them precisely, has led to plate models that differ in both the tim- ing and relative palaeo-positions of Iberia and Newfoundland during separation. We use newly available seismic data from the Southern Newfoundland Basin (SNB) to assess the suitability of com- monly used break-up markers along the Newfoundland mar- gin for plate kinematic reconstructions. Our data show that basement associated with the younger M-series magnetic anomalies is comprised of exhumed mantle and magmatic additions and most likely represents transitional domains and not true oceanic lithosphere. Because rifting propagated northward, we argue that M-series anomaly identifications further north, although in a region not imaged by our seis- mic, are also unlikely to be diagnostic of true oceanic crust beneath the SNB. Similarly, our data also allow us to show that the high amplitude of the J Anomaly is associated with a zone of exhumed mantle punctuated by significant volcanic additions and at times characterized by interbedded volcanics and sediments. Magmatic activity in the SNB at a time coin- ciding with M4 (128 Ma) and the presence of SDR packages onlapping onto a basement fault suggest that, at this time, plate divergence was still being accommodated by tectonic faulting. We illustrate the differences in the relative positions of Iberia and Newfoundland across published plate reconstruc- tions and discuss how these are a direct consequence of the uncertainties introduced into the modelling procedure by the use of extended continental margin data (dubious magnetic anomaly identifications, break-up unconformity interpreta- tions). We conclude that a different approach is needed for constraining plate kinematics of the Iberian plate pre-M0 times. |
format |
Article in Journal/Newspaper |
author |
Causer, Annabel Pérez-Díaz, Lucía Adam, Jürgen Eagles, Graeme |
spellingShingle |
Causer, Annabel Pérez-Díaz, Lucía Adam, Jürgen Eagles, Graeme Uncertainties in break-up markers along the Iberia–Newfoundland margins illustrated by new seismic data |
author_facet |
Causer, Annabel Pérez-Díaz, Lucía Adam, Jürgen Eagles, Graeme |
author_sort |
Causer, Annabel |
title |
Uncertainties in break-up markers along the Iberia–Newfoundland margins illustrated by new seismic data |
title_short |
Uncertainties in break-up markers along the Iberia–Newfoundland margins illustrated by new seismic data |
title_full |
Uncertainties in break-up markers along the Iberia–Newfoundland margins illustrated by new seismic data |
title_fullStr |
Uncertainties in break-up markers along the Iberia–Newfoundland margins illustrated by new seismic data |
title_full_unstemmed |
Uncertainties in break-up markers along the Iberia–Newfoundland margins illustrated by new seismic data |
title_sort |
uncertainties in break-up markers along the iberia–newfoundland margins illustrated by new seismic data |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://epic.awi.de/id/eprint/51558/ https://epic.awi.de/id/eprint/51558/1/Causer_etal_2020_SolidEarth_IberiaNewf.pdf https://hdl.handle.net/10013/epic.d67549f3-bb5f-4381-abc1-629f7d689f13 https://hdl.handle.net/ |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
EPIC3Solid Earth, Copernicus Publications, 11, pp. 397-417 |
op_relation |
https://epic.awi.de/id/eprint/51558/1/Causer_etal_2020_SolidEarth_IberiaNewf.pdf https://hdl.handle.net/ Causer, A. , Pérez-Díaz, L. , Adam, J. and Eagles, G. orcid:0000-0001-5325-0810 (2020) Uncertainties in break-up markers along the Iberia–Newfoundland margins illustrated by new seismic data , Solid Earth, 11 , pp. 397-417 . doi:10.5194/se-11-397-2020 <https://doi.org/10.5194/se-11-397-2020> , hdl:10013/epic.d67549f3-bb5f-4381-abc1-629f7d689f13 |
op_doi |
https://doi.org/10.5194/se-11-397-2020 |
container_title |
Solid Earth |
container_volume |
11 |
container_issue |
2 |
container_start_page |
397 |
op_container_end_page |
417 |
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1766094090881990656 |