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

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. [ABSTRACT FROM AUTHOR]