PRELIMINARY NOTE ON PALEOINTENSITIES OF THE GEOMAGNETIC FIELD OBTAINED FROM ROCKS IN ANTARCTICA
Thellier's method was applied to the metamorphic and volcanic rocks of the Napier Complex in Enderby Land, Ongul Islands, Mawson Station, Sor Rondane Mountains and McMurdo Sound. The samples treated have partly ambiguous ages and sometimes show undesirable thermomagnetic properties which cause...
Main Authors: | , , , |
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Format: | Report |
Language: | English |
Published: |
Natural Science Laboratory, Toyo University
1991
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Subjects: | |
Online Access: | https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2689 http://id.nii.ac.jp/1291/00002689/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2689&item_no=1&attribute_id=18&file_no=1 |
Summary: | Thellier's method was applied to the metamorphic and volcanic rocks of the Napier Complex in Enderby Land, Ongul Islands, Mawson Station, Sor Rondane Mountains and McMurdo Sound. The samples treated have partly ambiguous ages and sometimes show undesirable thermomagnetic properties which cause only a small linear portion in NRM-TRM diagrams and inconsistent paleointensity values for different specimens of the same sample. However, results from Enderby Land, Sor Rondane and McMurdo Sound indicate that geomagnetic field strength was 20% higher in the period of 2.5 Ga to 500Ma, 20% lower 500Ma ago and 30% higher 1 Ma ago than today, respectively. |
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