Journal of geomagnetism and geoelectricity

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The basic magnetic properties, hysteresis, AF demagnetization, thermal demagnetization and thermo-magnetic properties of samples from five kinds of formations in the basement complex of Wright Valley (77.53°S latitude and 161.63°E longitude), Southern Victoria Land, Antarctica, have been measured. The results suggest that every sample has a stable component of natural remanent magnetization (NRM): distributed on a meridian gathered gradually to low in latitude by thermal demagnetization up to 500°C: NRM distributed in high in latitude dispersed by thermal demagnetization less than 500°C: These characteristics are related to the Curie points of the samples.
The overall results are summarized as follows. The rocks now forming the floor of Wright Valley were heated to 500°C in the Jurassic by a hidden Ferrar dolerite body. Consequently primary magnetization was remagnetized far the samples which have a Curie point lower than 500°C, but survived for the samples included in magnetite grains. Virtual geomagnetic pole (VGP) positions obtained for samples of Cambro-Ordovician age rocks consistent with previous data from rocks of the same age in East Antarctica, the VGP being situated near the equator of Africa on the present continental distribution. The differences in the declination of the Cambro-Ordovician from East Antarctica are consistent with an angular rifting of 20°-30° having occurred subsequently within East Antarctica, probably along the line of the Amery Ice Shelf and Lambert Glacier. The Transantarctic Mountains are a part of East Antarctica and the boundary between and East-West Antarctica may be located in Ross-Weddell Sea.

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A discharge model around a positively charged body in a magnetized plasma has been studied experimentally in relation to the charging effect of a spacecraft emitting an electron beam in space. It has been found that there exist rotating electrons trapped around the charged body driven by the magnetic and electric fields, which can cause the ionization surrounding the charged body even under low pressure (Rotating Electrons Discharge). This effect gives the explanation for the experimental result that the charging effect of a spacecraft emitting a high power electron beam in the ionosphere has been generally much weaker than the predictions based on the theoretical charging models previously proposed.

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