High-Latitude Paleointensities During the Cretaceous Normal Superchron From the Okhotsk-Chukotka Volcanic Belt
We conducted an absolute paleointensity survey on 74 lava flows from the Okhotsk-Chukotka Volcanic Belt (NE Russia), emplaced 90-83 Ma toward the end of the Cretaceous Normal Superchron (CNS, 121-84 Ma). Relying on preliminary results, we restricted our analysis to eight lava flows (140 Thellier-Coe...
Published in: | Journal of Geophysical Research: Solid Earth |
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Language: | English |
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Ludwig-Maximilians-Universität München
2022
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Online Access: | https://epub.ub.uni-muenchen.de/107071/1/JGR%20Solid%20Earth%20-%202022%20-%20Bobrovnikova.pdf https://epub.ub.uni-muenchen.de/107071/ http://nbn-resolving.de/urn:nbn:de:bvb:19-epub-107071-3 https://doi.org/10.1029/2021JB023551 |
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ftmuenchenepub:oai:epub.ub.uni-muenchen.de:107071 2023-10-09T21:50:45+02:00 High-Latitude Paleointensities During the Cretaceous Normal Superchron From the Okhotsk-Chukotka Volcanic Belt Bobrovnikova, E. M. Lhuillier, Florian Shcherbakov, V. P. Shcherbakova, V. V. Zhidkov, G. V. Lebedev, I. E. Eid, B. Pavlov, V. E. 2022-01-01 application/pdf https://epub.ub.uni-muenchen.de/107071/1/JGR%20Solid%20Earth%20-%202022%20-%20Bobrovnikova.pdf https://epub.ub.uni-muenchen.de/107071/ http://nbn-resolving.de/urn:nbn:de:bvb:19-epub-107071-3 https://doi.org/10.1029/2021JB023551 eng eng Ludwig-Maximilians-Universität München Bobrovnikova, E. M.; Lhuillier, Florian ORCID logoorcid:0000-0002-6309-0248 Shcherbakov, V. P.; Shcherbakova, V. V.; Zhidkov, G. V.; Lebedev, I. E.; Eid, B. und Pavlov, V. E. (2022): High-Latitude Paleointensities During the Cretaceous Normal Superchron From the Okhotsk-Chukotka Volcanic Belt. In: Journal of Geophysical Research JGR / Solid Earth, Vol. 127, Nr. 2 [PDF, 3MB] https://epub.ub.uni-muenchen.de/107071/1/JGR%20Solid%20Earth%20-%202022%20-%20Bobrovnikova.pdf http://nbn-resolving.de/urn:nbn:de:bvb:19-epub-107071-3 https://epub.ub.uni-muenchen.de/107071/ doi:10.1029/2021JB023551 Journal of Geophysical Research JGR / Solid Earth Department für Geo- und Umweltwissenschaften ddc:550 doc-type:article Zeitschriftenartikel NonPeerReviewed 2022 ftmuenchenepub https://doi.org/10.1029/2021JB023551 2023-09-17T23:38:34Z We conducted an absolute paleointensity survey on 74 lava flows from the Okhotsk-Chukotka Volcanic Belt (NE Russia), emplaced 90-83 Ma toward the end of the Cretaceous Normal Superchron (CNS, 121-84 Ma). Relying on preliminary results, we restricted our analysis to eight lava flows (140 Thellier-Coe experiments), two of which also yielded successful Wilson determinations. A detailed analysis of the magneto-mineralogy-based on X-ray structural analysis, reflected-light microscopy, and thermomagnetic curves-indicates that the determinations from solely two lava flows can be fully trusted, with remanence carriers (a) dominated by low-titanium titanomagnetite, (b) showing unambiguous traces of high-temperature oxidation, and (c) yielding partial thermoremanent magnetization (pTRM) tails representative of pseudo-single-domain grains. Recalculated in terms of geomagnetic dipole strength, our two successful flow-mean determinations yield virtual dipole moments of 4.76 +/- 0.26 x 10(22) Am-2 (N = 7) and 9.07 +/- 0.84 x 10(22) Am-2 (N = 8). Using an updated version of the paleointensity database for the Cretaceous epoch, we stress that determinations based on nonglassy whole rocks, submarine basaltic glasses, and single crystals are mutually inconsistent, suggesting a separate analysis of their distributions is more appropriate. Despite statistically indistinguishable estimates of dipole strength before and after the onset of the CNS-in accord with recent studies refuting the existence of a strict correlation between chron duration and dipole moment-we found that the distribution of dipole moments during the CNS is slightly bimodal with a leptokurtic dominant mode, thus more inclined to produce outliers and suggesting distinct geomagnetic field behavior during the CNS. Article in Journal/Newspaper Chukotka Open Access LMU (Ludwig-Maximilians-University Munich) Okhotsk Journal of Geophysical Research: Solid Earth 127 2 |
institution |
Open Polar |
collection |
Open Access LMU (Ludwig-Maximilians-University Munich) |
op_collection_id |
ftmuenchenepub |
language |
English |
topic |
Department für Geo- und Umweltwissenschaften ddc:550 |
spellingShingle |
Department für Geo- und Umweltwissenschaften ddc:550 Bobrovnikova, E. M. Lhuillier, Florian Shcherbakov, V. P. Shcherbakova, V. V. Zhidkov, G. V. Lebedev, I. E. Eid, B. Pavlov, V. E. High-Latitude Paleointensities During the Cretaceous Normal Superchron From the Okhotsk-Chukotka Volcanic Belt |
topic_facet |
Department für Geo- und Umweltwissenschaften ddc:550 |
description |
We conducted an absolute paleointensity survey on 74 lava flows from the Okhotsk-Chukotka Volcanic Belt (NE Russia), emplaced 90-83 Ma toward the end of the Cretaceous Normal Superchron (CNS, 121-84 Ma). Relying on preliminary results, we restricted our analysis to eight lava flows (140 Thellier-Coe experiments), two of which also yielded successful Wilson determinations. A detailed analysis of the magneto-mineralogy-based on X-ray structural analysis, reflected-light microscopy, and thermomagnetic curves-indicates that the determinations from solely two lava flows can be fully trusted, with remanence carriers (a) dominated by low-titanium titanomagnetite, (b) showing unambiguous traces of high-temperature oxidation, and (c) yielding partial thermoremanent magnetization (pTRM) tails representative of pseudo-single-domain grains. Recalculated in terms of geomagnetic dipole strength, our two successful flow-mean determinations yield virtual dipole moments of 4.76 +/- 0.26 x 10(22) Am-2 (N = 7) and 9.07 +/- 0.84 x 10(22) Am-2 (N = 8). Using an updated version of the paleointensity database for the Cretaceous epoch, we stress that determinations based on nonglassy whole rocks, submarine basaltic glasses, and single crystals are mutually inconsistent, suggesting a separate analysis of their distributions is more appropriate. Despite statistically indistinguishable estimates of dipole strength before and after the onset of the CNS-in accord with recent studies refuting the existence of a strict correlation between chron duration and dipole moment-we found that the distribution of dipole moments during the CNS is slightly bimodal with a leptokurtic dominant mode, thus more inclined to produce outliers and suggesting distinct geomagnetic field behavior during the CNS. |
format |
Article in Journal/Newspaper |
author |
Bobrovnikova, E. M. Lhuillier, Florian Shcherbakov, V. P. Shcherbakova, V. V. Zhidkov, G. V. Lebedev, I. E. Eid, B. Pavlov, V. E. |
author_facet |
Bobrovnikova, E. M. Lhuillier, Florian Shcherbakov, V. P. Shcherbakova, V. V. Zhidkov, G. V. Lebedev, I. E. Eid, B. Pavlov, V. E. |
author_sort |
Bobrovnikova, E. M. |
title |
High-Latitude Paleointensities During the Cretaceous Normal Superchron From the Okhotsk-Chukotka Volcanic Belt |
title_short |
High-Latitude Paleointensities During the Cretaceous Normal Superchron From the Okhotsk-Chukotka Volcanic Belt |
title_full |
High-Latitude Paleointensities During the Cretaceous Normal Superchron From the Okhotsk-Chukotka Volcanic Belt |
title_fullStr |
High-Latitude Paleointensities During the Cretaceous Normal Superchron From the Okhotsk-Chukotka Volcanic Belt |
title_full_unstemmed |
High-Latitude Paleointensities During the Cretaceous Normal Superchron From the Okhotsk-Chukotka Volcanic Belt |
title_sort |
high-latitude paleointensities during the cretaceous normal superchron from the okhotsk-chukotka volcanic belt |
publisher |
Ludwig-Maximilians-Universität München |
publishDate |
2022 |
url |
https://epub.ub.uni-muenchen.de/107071/1/JGR%20Solid%20Earth%20-%202022%20-%20Bobrovnikova.pdf https://epub.ub.uni-muenchen.de/107071/ http://nbn-resolving.de/urn:nbn:de:bvb:19-epub-107071-3 https://doi.org/10.1029/2021JB023551 |
geographic |
Okhotsk |
geographic_facet |
Okhotsk |
genre |
Chukotka |
genre_facet |
Chukotka |
op_source |
Journal of Geophysical Research JGR / Solid Earth |
op_relation |
Bobrovnikova, E. M.; Lhuillier, Florian ORCID logoorcid:0000-0002-6309-0248 Shcherbakov, V. P.; Shcherbakova, V. V.; Zhidkov, G. V.; Lebedev, I. E.; Eid, B. und Pavlov, V. E. (2022): High-Latitude Paleointensities During the Cretaceous Normal Superchron From the Okhotsk-Chukotka Volcanic Belt. In: Journal of Geophysical Research JGR / Solid Earth, Vol. 127, Nr. 2 [PDF, 3MB] https://epub.ub.uni-muenchen.de/107071/1/JGR%20Solid%20Earth%20-%202022%20-%20Bobrovnikova.pdf http://nbn-resolving.de/urn:nbn:de:bvb:19-epub-107071-3 https://epub.ub.uni-muenchen.de/107071/ doi:10.1029/2021JB023551 |
op_doi |
https://doi.org/10.1029/2021JB023551 |
container_title |
Journal of Geophysical Research: Solid Earth |
container_volume |
127 |
container_issue |
2 |
_version_ |
1779313811686162432 |