Department of Chemistry, The University of Tokyo/Department of Chemistry, The University of Tokyo/Department of Chemistry, The University of Tokyo
抄録(英)
The REE abundances and the Sr isotopic compositions were determined for the separated samples and the clast sample of the "lunar meteorite", Yamato-791197. Most of the features of the REE patterns are similar to those of the lunar highland samples, especially a kind of anorthosites. And the positive Ce-anomalies, shown in all REE patterns, appear characteristic of the lunar origin. The age obtained from the Rb-Sr system is 3.89±0.36 b. y. and it is considered that this age shows the time when these materials underwent an event, such as brecciation or impact melting. However, as a noticeable point, the initial ^<87>Sr/^<86>Sr is significantly low, even lower than BABI or LUNI. This result suggests that the source material of these samples might have had very low ^<87>Sr/^<86>Sr and Rb/Sr abundance ratios. The clast sample from the chip subordinate No. 109 has the distinct REE pattern and Sr-isotope ratio. Therefore, this clast can be considered to have been formed by different evolution process from the other samples, and was mingled later with them.
雑誌書誌ID
AA00733561
雑誌名
Memoirs of National Institute of Polar Research. Special issue
REE adundances and Rb-Sr geochronology of Yamato-791197
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KJ00000012509
(1.24MB)
概要
