School of Earth Sciences, IHS, Kyoto University
National Institute of Polar Reserch
抄録(英)
Samples collected at eight sites from granulites of the Archean Napier Complex and dolente dikes intruding the complex in the Mt. Riiser-Larsen area, East Antarctica, were analyzed rock-magnetically in order to assess the stability of their natural remanent magnetizations (NRMs). Results of isothermal remanence acquisition experiments and hysteresis measurements indicate the presence of magnetite in the pseudo-single to multi domain size, which is consistent with N. ISHIKAWA and M. FUNAKI (Proc. NIPR Symp. Antarct. Geosci., 10, 79, 1997). Stable magnetic components carried by fine-grained magnetites were isolated from some sites. Samples with such components may have a mixture of magnetites with different grain sizes although the effect of the mixing was not clearly observed. Heavily-deformed samples were found to be magnetically amsotropic, while magnetic fabrics of less-deformed samples indicate the possibility that the fabrics are of primary origin. The high-stability magnetic components from the less-deformed dolente samples of one site with primary magnetic fabrics may be of primary remanence acquired in the emplacement of the dike at 0.8-1.0Ga.
Rock magnetic analysis for samples of the Napier Complex in the Mt. Riiser-Larsen area, East Antarctica
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KJ00000044139
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概要
