Geochronologists at the University of California found that the stone tools from Gona were made just before the magnetic field shift which began the Matayama epoch.
加州大学的地质年代学家们发现，戈纳石器正是在标志更新世开端的那次磁场逆转发生之前制造的。
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It is really possible that the Sun possesses a relic magnetic field of the pre-main sequence epoch in its radiative core.