Compositions of Ni-rich magnesiowüstite and coexisting magnesioferrite spinel from sediments of DSDP Holes 86-577 and 91-596
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| Natura: | Dataset Open Access |
| Lingua: | en |
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PANGAEA
1995
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| _version_ | 1867168552542273536 |
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| author | Kyte, Frank T Bohor, Bruce F |
| author_facet | Kyte, Frank T Bohor, Bruce F |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | We have found trace inclusions of Ni-rich magnesiowüstite within grains of magnesioferrite spinel recovered from Cretaceous/Tertiary boundary sediments from DSDP Site 596, South Pacific (23°51.20'S, 169°39.27'W) and DSDP Site 577, North Pacific (3°6.51'N, 157°43.40'E). Measured compositions of these inclusions range from (Mg_0.85Ni_0.74Fe_0.17)O to (Mg_0.74Ni_0.09Fe_0.17)O. Coexisting magnesioferrite and magnesiowüstite can only crystallize from ultramafic, refractory, Mg-rich liquids with Mg/Si > 2 (atom ratio). Such liquid compositions cannot form as a result of fractional crystallization and are unknown to occur as a result of terrestrial igneous processes or meteoroid ablation. We infer that these minerals crystallized from liquid droplets that equilibrated with silicate vapor at high temperatures (probably >2300°C), resulting in fractionation of volatile SiO2 from more refractory MgO. The most plausible source of this high-temperature vapor is in the fireball of the major impact event that terminated the Cretaceous. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_708055 |
| institution | PANGAEA |
| language | en |
| publishDate | 1995 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Compositions of Ni-rich magnesiowüstite and coexisting magnesioferrite spinel from sediments of DSDP Holes 86-577 and 91-596 Kyte, Frank T Bohor, Bruce F 86-577; 91-596; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; Glomar Challenger; Leg86; Leg91; North Pacific Ocean; South Pacific Ocean We have found trace inclusions of Ni-rich magnesiowüstite within grains of magnesioferrite spinel recovered from Cretaceous/Tertiary boundary sediments from DSDP Site 596, South Pacific (23°51.20'S, 169°39.27'W) and DSDP Site 577, North Pacific (3°6.51'N, 157°43.40'E). Measured compositions of these inclusions range from (Mg_0.85Ni_0.74Fe_0.17)O to (Mg_0.74Ni_0.09Fe_0.17)O. Coexisting magnesioferrite and magnesiowüstite can only crystallize from ultramafic, refractory, Mg-rich liquids with Mg/Si > 2 (atom ratio). Such liquid compositions cannot form as a result of fractional crystallization and are unknown to occur as a result of terrestrial igneous processes or meteoroid ablation. We infer that these minerals crystallized from liquid droplets that equilibrated with silicate vapor at high temperatures (probably >2300°C), resulting in fractionation of volatile SiO2 from more refractory MgO. The most plausible source of this high-temperature vapor is in the fireball of the major impact event that terminated the Cretaceous. |
| title | Compositions of Ni-rich magnesiowüstite and coexisting magnesioferrite spinel from sediments of DSDP Holes 86-577 and 91-596 |
| topic | 86-577; 91-596; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; Glomar Challenger; Leg86; Leg91; North Pacific Ocean; South Pacific Ocean |
| url | https://doi.org/10.1594/PANGAEA.708055 |