Analyzing Triassic and Permian Geomagnetic Paleosecular Variation and the Implications for Ancient Field Morphology
Abstract Studying paleosecular variation (PSV) can provide unique insights into the average morphology of the geomagnetic field and the operation of the geodynamo. Although recent studies have expanded our knowledge of paleomagnetic field behavior through the late Mesozoic, relatively little is know...
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ftdoajarticles:oai:doaj.org/article:5acc753add9c471283edfbe0c9aad9b3 2023-12-03T10:22:58+01:00 Analyzing Triassic and Permian Geomagnetic Paleosecular Variation and the Implications for Ancient Field Morphology B. T. Handford A. J. Biggin M. M. Haldan C. G. Langereis 2021-11-01T00:00:00Z https://doi.org/10.1029/2021GC009930 https://doaj.org/article/5acc753add9c471283edfbe0c9aad9b3 EN eng Wiley https://doi.org/10.1029/2021GC009930 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2021GC009930 https://doaj.org/article/5acc753add9c471283edfbe0c9aad9b3 Geochemistry, Geophysics, Geosystems, Vol 22, Iss 11, Pp n/a-n/a (2021) paleosecular variation Triassic geomagnetic field morphology PCRS geomagnetic reversal frequency core dynamics Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.1029/2021GC009930 2023-11-05T01:35:57Z Abstract Studying paleosecular variation (PSV) can provide unique insights into the average morphology of the geomagnetic field and the operation of the geodynamo. Although recent studies have expanded our knowledge of paleomagnetic field behavior through the late Mesozoic, relatively little is known regarding the Triassic period (ca. 251.9–201.3 Ma). This study compiles the first Triassic virtual geomagnetic pole (VGP) database for the analysis of PSV, as part of a longer Post‐Permo‐Carboniferous Reversed Superchron (PCRS) time interval (265‐198 Ma). VGP angular dispersion and its dependence on apparent paleolatitude are compared against a new PCRS compilation and published PSV compilations for intervals across the last ∼320 Ma. We find that the Post‐PCRS displays near latitudinal invariance of VGP dispersion while the PCRS displays very strong latitudinal dependence. PSV behavior during the Post‐PCRS appears indistinguishable to that previously reported for the interval preceding the Cretaceous Normal Superchron (Pre‐CNS; 126–198 Ma). The near‐constant behavior between time intervals with significantly different apparent average polarity reversal frequencies does not support a suggested relationship between VGP dispersion and reversal frequency. The dispersion observed for the PCRS is consistent with the results of previous studies and represents behavior that is potentially unique over the last ∼320 Ma. A recently published approach to obtain a description of field morphology from equatorial VGP dispersion shows the PCRS geomagnetic field to have been more strongly axial dipole dominated than any interval since. This observation may be causally linked to the PCRS being the longest known superchron in the Phanerozoic geomagnetic polarity timescale. Article in Journal/Newspaper Geomagnetic Pole Directory of Open Access Journals: DOAJ Articles Geochemistry, Geophysics, Geosystems 22 11 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
paleosecular variation Triassic geomagnetic field morphology PCRS geomagnetic reversal frequency core dynamics Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
spellingShingle |
paleosecular variation Triassic geomagnetic field morphology PCRS geomagnetic reversal frequency core dynamics Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 B. T. Handford A. J. Biggin M. M. Haldan C. G. Langereis Analyzing Triassic and Permian Geomagnetic Paleosecular Variation and the Implications for Ancient Field Morphology |
topic_facet |
paleosecular variation Triassic geomagnetic field morphology PCRS geomagnetic reversal frequency core dynamics Geophysics. Cosmic physics QC801-809 Geology QE1-996.5 |
description |
Abstract Studying paleosecular variation (PSV) can provide unique insights into the average morphology of the geomagnetic field and the operation of the geodynamo. Although recent studies have expanded our knowledge of paleomagnetic field behavior through the late Mesozoic, relatively little is known regarding the Triassic period (ca. 251.9–201.3 Ma). This study compiles the first Triassic virtual geomagnetic pole (VGP) database for the analysis of PSV, as part of a longer Post‐Permo‐Carboniferous Reversed Superchron (PCRS) time interval (265‐198 Ma). VGP angular dispersion and its dependence on apparent paleolatitude are compared against a new PCRS compilation and published PSV compilations for intervals across the last ∼320 Ma. We find that the Post‐PCRS displays near latitudinal invariance of VGP dispersion while the PCRS displays very strong latitudinal dependence. PSV behavior during the Post‐PCRS appears indistinguishable to that previously reported for the interval preceding the Cretaceous Normal Superchron (Pre‐CNS; 126–198 Ma). The near‐constant behavior between time intervals with significantly different apparent average polarity reversal frequencies does not support a suggested relationship between VGP dispersion and reversal frequency. The dispersion observed for the PCRS is consistent with the results of previous studies and represents behavior that is potentially unique over the last ∼320 Ma. A recently published approach to obtain a description of field morphology from equatorial VGP dispersion shows the PCRS geomagnetic field to have been more strongly axial dipole dominated than any interval since. This observation may be causally linked to the PCRS being the longest known superchron in the Phanerozoic geomagnetic polarity timescale. |
format |
Article in Journal/Newspaper |
author |
B. T. Handford A. J. Biggin M. M. Haldan C. G. Langereis |
author_facet |
B. T. Handford A. J. Biggin M. M. Haldan C. G. Langereis |
author_sort |
B. T. Handford |
title |
Analyzing Triassic and Permian Geomagnetic Paleosecular Variation and the Implications for Ancient Field Morphology |
title_short |
Analyzing Triassic and Permian Geomagnetic Paleosecular Variation and the Implications for Ancient Field Morphology |
title_full |
Analyzing Triassic and Permian Geomagnetic Paleosecular Variation and the Implications for Ancient Field Morphology |
title_fullStr |
Analyzing Triassic and Permian Geomagnetic Paleosecular Variation and the Implications for Ancient Field Morphology |
title_full_unstemmed |
Analyzing Triassic and Permian Geomagnetic Paleosecular Variation and the Implications for Ancient Field Morphology |
title_sort |
analyzing triassic and permian geomagnetic paleosecular variation and the implications for ancient field morphology |
publisher |
Wiley |
publishDate |
2021 |
url |
https://doi.org/10.1029/2021GC009930 https://doaj.org/article/5acc753add9c471283edfbe0c9aad9b3 |
genre |
Geomagnetic Pole |
genre_facet |
Geomagnetic Pole |
op_source |
Geochemistry, Geophysics, Geosystems, Vol 22, Iss 11, Pp n/a-n/a (2021) |
op_relation |
https://doi.org/10.1029/2021GC009930 https://doaj.org/toc/1525-2027 1525-2027 doi:10.1029/2021GC009930 https://doaj.org/article/5acc753add9c471283edfbe0c9aad9b3 |
op_doi |
https://doi.org/10.1029/2021GC009930 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
22 |
container_issue |
11 |
_version_ |
1784270998835560448 |