TY - JOUR

T1 - Absolute Geomagnetic Paleointensity at the Permian–Triassic Boundary: the Problem of the Mesozoic Dipole Low

AU - Metelkin, D. V.

AU - Eliseev, A. A.

AU - Shcherbakova, V. V.

AU - Mikhaltsov, N. E.

AU - Zhidkov, G. V.

AU - Abashev, V. V.

N1 - This work was supported by the Russian Science Foundation project no. 23-77-01065 (paleointensity measurement experiments), project no. 24-17-00057 (analysis of the geology and geodynamic events), as well as the Ministry of Science and Higher Education of Russia, grant no. FSUS-2020-0039 (analysis of the geomagnetic field paleointensity relationship to mantle plume evolution). The research topic is coordinated with the programs of fundamental research of the RAS no. FWZZ-2022-0001 and no. FMWU-2022-0026.

PY - 2024

Y1 - 2024

N2 - We report new estimates of the intensity of the geomagnetic field strength for the Permian–Triassic boundary. Amid predominantly low virtual dipole moment values for that time in the Global Paleointensity Database, episodes of increased VDM up to 8.9 × 1022 Am2 were recorded in the sections of the trap formation of the Kuznetsk depression, which do not conform to the Mesozoic Dipole Low concept. Analysis of data on changes in the value of the virtual dipole moment during the formation of the Siberian Large Igneous Province within the framework of modern magnetostratigraphic correlations indicates a persistently weak geomagnetic field only at the initial stage, when most of its Norilsk area was formed. A change in the geomagnetic mode is noted after ~800 thousand years at the level of subchron LT1n.1r (251.2–251.1 Ma) of the General Magnetostratigraphic Scale and was recorded in the basaltic andesite lava sheets of the Kuznetsk area. Low virtual dipole moment values from this time correspond to episodes of reversals, while the overall intensity was on average only slightly lower than today. Thus, the drop in paleointensity at the very beginning of the Triassic period was not caused by a major long-term change in the geodynamo, but was short-term and related to plume activity.

AB - We report new estimates of the intensity of the geomagnetic field strength for the Permian–Triassic boundary. Amid predominantly low virtual dipole moment values for that time in the Global Paleointensity Database, episodes of increased VDM up to 8.9 × 1022 Am2 were recorded in the sections of the trap formation of the Kuznetsk depression, which do not conform to the Mesozoic Dipole Low concept. Analysis of data on changes in the value of the virtual dipole moment during the formation of the Siberian Large Igneous Province within the framework of modern magnetostratigraphic correlations indicates a persistently weak geomagnetic field only at the initial stage, when most of its Norilsk area was formed. A change in the geomagnetic mode is noted after ~800 thousand years at the level of subchron LT1n.1r (251.2–251.1 Ma) of the General Magnetostratigraphic Scale and was recorded in the basaltic andesite lava sheets of the Kuznetsk area. Low virtual dipole moment values from this time correspond to episodes of reversals, while the overall intensity was on average only slightly lower than today. Thus, the drop in paleointensity at the very beginning of the Triassic period was not caused by a major long-term change in the geodynamo, but was short-term and related to plume activity.

KW - Kuznetsk depression

KW - Mesozoic Dipole Low

KW - Permian–Triassic boundary

KW - Siberian large igneous province

KW - Thellier-Coe method

KW - paleointensity

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85205565100&origin=inward&txGid=5cff243cfacd3d87134151f9daa81ba2

UR - https://www.mendeley.com/catalogue/82f99f51-6554-3af6-856b-b1c3a71a99d3/

U2 - 10.1134/S1028334X24603687

DO - 10.1134/S1028334X24603687

M3 - Article

JO - Doklady Earth Sciences

JF - Doklady Earth Sciences

SN - 1028-334X

ER -