Rock magnetic analysis for samples of the Napier Complex in the Mt. Riiser-Larsen area, East Antarctica
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 isotherm...
| Main Authors: | , |
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| Format: | Report |
| Language: | English |
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School of Earth Sciences, IHS, Kyoto University
1998
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| Online Access: | https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3022 http://id.nii.ac.jp/1291/00003022/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3022&item_no=1&attribute_id=18&file_no=1 |
| Summary: | 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. |
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