PERIDOTITES FROM THE SEAMOUNT OFF WILKES LAND, ANTARCTICA
Dredged peridotite-pyroxenite samples from Antarctic Seamount B were examined to clarify the petrological signature. It is suggested from the tectonic setting that the emplacement of the peridotites was achieved by uplifting of upper mantle materials generated as a pre-oceanic rifting at the early s...
| Main Authors: | , , , |
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| Format: | Report |
| Language: | English |
| Published: |
Department of Earth and Planetary Sciences, Graduate School of Science, Hokkaido University
1995
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| Subjects: | |
| Online Access: | https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2794 http://id.nii.ac.jp/1291/00002794/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2794&item_no=1&attribute_id=18&file_no=1 |
| Summary: | Dredged peridotite-pyroxenite samples from Antarctic Seamount B were examined to clarify the petrological signature. It is suggested from the tectonic setting that the emplacement of the peridotites was achieved by uplifting of upper mantle materials generated as a pre-oceanic rifting at the early stage of continental breakup between Antarctica and Australia. The Seamount B lherzolites contain a large volume of clinopyroxenes (6.5-12.9 modal%) and spinels (2.0-2.9 modal%). The Fo content in olivines ranges between 89.5 and 92.3. The spinels are highly aluminous (Cr#=7.8-15.7). Notably, the clinopyroxenes contain high Na_2O (1.24-2.35 wt%) and TiO_2 (0.27 to 0.85 wt%). The modal composition and mineral chemistry suggest that the Seamount B lherzolites display a 'fertile' subcontinental mantle signature ranging from the least to moderately depleted peridotite. |
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