The Earth's magnetic field during the Neoproterozoic Ediacaran period was in an abnormal state, and during this period, the Ediacaran soft bodied multicellular invertebrate community rapidly diversified and flourished. However, there is no consensus on whether there is a correlation between the two.

Recently, the collision uplift and impact team led by Huang Wentao, a researcher at the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences, joined with researchers from the University of Rochester, Virginia Tech, Nanjing University and other universities to separate plagioclase particles from the slowly cooling Bushveld pyroxenite and Basi gabbro in South Africa. The magnetic carrying minerals of these plagioclase particles are needle shaped single domain (titanium) magnetite that melts at high temperatures during magma cooling. Their particle size is less than 200 nm, recording primary remanence and making them ideal materials for testing paleomagnetic field strength. The experiment used the most accurate Thellier Coe method for ancient intensity testing, based on rapid heating with CO2 laser, and strict data screening standards were used to exclude oxidized samples. High quality ancient intensity data were obtained for 22 Bushvelde plagioclase particles and 21 Brazilian plagioclase particles. The data shows that the geomagnetic field intensity recorded by Bushveld pyroxenite is 69.0 ± 4.3 μ T. The geomagnetic field intensity recorded by Brazilian gabbro is 2.73 ± 0.69 μ T. After correcting for anisotropy and cooling rate of the data, the time averaged geomagnetic field dipole moments obtained from 2.05 billion years ago and 591 million years ago were 8.04 ± 0.40 x 1022 Am2 and 0.25 ± 0.02 x 1022 Am2, respectively. This indicates that the ancient geomagnetic field intensity was 30% higher than today's geomagnetic field intensity 2.05 billion years ago, while the geomagnetic field intensity 591 million years ago was only 1/30 of today's, which is currently the lowest reported geomagnetic field intensity. Based on previous research findings, it is inferred that the strong geomagnetic field period of the Archean extended to the Paleoproterozoic. At the same time, there was an extremely weak geomagnetic field period during the Ediacaran period with an intensity less than 10% of the current magnetic field strength. This period lasted from at least 591 million years ago to 565 million years ago, lasting for 26 million years.

Paleontological research has found that the population of the Ediacaran fauna has rapidly increased since 575 million years ago and reached its peak 565 million years ago. Previous studies on the sudden emergence of the Ediacaran fauna have focused on genetics, ecology, and consideration of environmental factors. The emergence and prosperity of the Ediacaran fauna coincided with the extremely weak geomagnetic field period defined by scientists during the Ediacaran period. The team re examined the driving forces of environmental factors, particularly the impact of oxygen enrichment events in the atmosphere and oceans. Research has found that macroorganisms with complex morphology and free movement have high requirements for environmental oxygen content; Animal ecosystems with long food chains require a large amount of oxygen support; The Ediacaran fauna has macro mobile animals with dimensions reaching the decimeter level, which have a high demand for oxygen content. Geochemical studies have shown that the oxygen content in the atmosphere and oceans increased during the Late Ediacaran period, particularly in the Shuram that appeared 575-565 million years ago δ During the negative bias period of 13C. Deposited in black shale 570-560 million years ago δ 98Mo and δ The increase in 82/76Se and the abundance of elements such as [Mo], [U], and [V] indicate an increase in oxygen content in the environment. The sudden appearance and prosperity of the Ediacaran fauna recorded in paleontology, the extremely weak geomagnetic field period determined by paleomagnetic research, and the oxygenation events shown by geochemical research all show simultaneity. Therefore, the correlation between them deserves further research.
There are two mechanisms for the escape of hydrogen (H) from outer space - thermal and non thermal, both of which can increase the oxygen content in the atmosphere. The climate change and methane release indicated by the isotopic records of the Ediacaran period may generate favorable thermal conditions for H escape, but there is controversy. The solar wind evolution model can be used to calculate that the steady-state magnetic top height was less than 4.5R ⊕ (R ⊕ refers to the radius of the Earth) 565 million years ago, less than 4.2R ⊕ 591 million years ago, and less than about 10.7R ⊕ today. During periods of extreme solar activity during massive coronal eruptions, the height of the magnetopause may be compressed to 1.6 R ⊕. The reduced height of the magnetic top layer expands the area of the non closed magnetic field lines in the polar regions and increases the non thermal escape channel of H. The area of the non closed magnetic field lines in the polar regions was 3.5 times that of today's area 591 million years ago, and this area may have been larger during periods of massive coronal eruptions. In addition, the height of the magnetic top layer that decreases during the extremely weak geomagnetic field period may be close to or even lower than the height of the ionosphere, and the plasma in the ionosphere is mainly composed of H+, resulting in more H+escape. The narrowing of the magnetosphere during the extremely weak geomagnetic field makes it easier for the solar wind to bombard more H atoms in the atmosphere, allowing them to gain kinetic energy and escape. The reduced height of the magnetic top layer allows more high-energy protons to penetrate the atmosphere at a greater angle, catalyzing photochemical reactions to generate nitrogen oxides, causing holes in the ozone layer. The decomposition of water vapor caused by strong ultraviolet radiation causes H to transport and escape into outer space. Under weak to extremely weak geomagnetic field conditions, the escape of H from the Earth's magnetosphere through the aforementioned process may last for tens of millions to billions of years, leading to a sustained increase in oxygen content in the atmosphere. This laid the oxygen foundation for the prosperity of the Ediacaran fauna and the subsequent Cambrian explosion of life.

The relevant research results, as a highlight on the cover, have been published in the journal Communications Earth&Environment under the title of Near collapse of the geospatial field may have contributed to atmospheric oxygen and animal radiation in the Ediacaran Period.

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