Melting of a Yamato L3 chondrite (Y-74191) up to 30 kbar
Melting phase relations of a Yamato L3 chondrite (Y-74191) have been studied in the pressure range 6 to 30 kbar. Solidus of the chondrite is defined by eutectic melting of Fe-Ni-S at about 950℃ regardless of pressure. At 15 kbar, silicate solidus of the chondrite is about 250℃ higher than the metal/...
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Format: | Report |
Language: | English |
Published: |
Institute for Thermal Spring Research,Okayama University
1983
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Online Access: | https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1558 http://id.nii.ac.jp/1291/00001558/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1558&item_no=1&attribute_id=18&file_no=1 |
Summary: | Melting phase relations of a Yamato L3 chondrite (Y-74191) have been studied in the pressure range 6 to 30 kbar. Solidus of the chondrite is defined by eutectic melting of Fe-Ni-S at about 950℃ regardless of pressure. At 15 kbar, silicate solidus of the chondrite is about 250℃ higher than the metal/sulfide eutectic solidus and the temperature interval between the two solidi widens as pressure increases. Composition of the metal/sulfide melt changes from FeS-rich to Fe-Ni-rich as temperature increases. Ferrobasaltic liquids containing 18 to 23wt% FeO and 0.2wt% sulfur are produced as partial melts over a large pressure and temperature interval. At low temperatures below the silicate solidus, the metal/sulfide melts are small isolated patches dispersed in grain boundaries of silicate minerals. At high temperatures, the metal/sulfide melts become numerous globules surrounded by silicate melts. Segregation of the ferrobasaltic partial melt on top of the residual olivines and the metal/sulfide globules has been observed. Gravitational settling of the dense metal/sulfide globules, however, did not take place under any experimental condition at least up to 10hr. Based on the partial melting experiments a model for genesis of pallasite meteorite is proposed. |
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