Chemical composition of Y-793605, a martian lherzolite

概要

論文の詳細を見る
As a part of consortium study, we have analyzed the Yamato-793605 lherzolitic shergottite by instrumental neutron activation analysis (INAA), radiochemical neutron activation analysis (RNAA) and inductively coupled plasma mass spectrometry (ICP-MS). For comparison, ALH 77005 was also analyzed by INAA and RNAA. Compositionally, Y-793605 is similar to ALH 77005 (and also to LEW 88516). REE abundances for Y-793605 are similar to but slightly lower than those for ALH 77005 and are characterized by a hump around Dy in the CI-normalized pattern. Iridium/Os ratios of Y-793605 and ALH 77005 are exactly chondritic, suggesting that the shergottite parent material had an approximately chondritic Ir/Os ratio. On the other hand, Ni/Co ratios of these two lherzolitic shergottites are lower than the CI value, with both elements being more abundant than refractory siderophiles such as Os and Ir. Presumably, both elements partly existed as oxides when the core formation occurred, but Ni was partitioned into the core more effectively than Co because of the higher stability of the Co oxide. Molybdenum and W are also largely fractionated in Y-793605 and ALH 77005,with Mo being more depleted than W. Apparently, segregation of W into the core was inefficient whereas Mo was more effectively incorporated into the metal-sulfide core. These observations suggest that the oxygen fugacity was considerably elevated when the core formed (at least at the latest stage of core formation).
国立極地研究所の論文

Chemical composition of Y-793605, a martian lherzolite

スポンサーリンク

概要

著者

関連論文

スポンサーリンク