著者

吉原 新

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.114, no.2, pp.212-222, 2005-04-25 (Released:2009-11-12)

参考文献数

52

被引用文献数

1 1

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Knowledge of the Earth's magnetic field during Archean and Proterozoic times can provide important sources of information for understanding the internal and environmental evolution of the Earth. The long-term variation in field intensity and reversal rate is considered to reflect mode changes in powering the geodynamo. Several recent efforts to reconstruct the magnetic field of the early Earth have reported relatively low to moderate field accompanied by occasional polarity reversals. The volume of reliable paleomagnetic data, however, is still insufficient to characterize its long-term nature. Here, recent paleointensity and paleodirectional studies on Archean and Proterozoic rocks including our new findings are reviewed, and their problems and further perspectives are argued.