論文

査読有り
2017年11月

Formation of a metastable hollandite phase from amorphous plagioclase: A possible origin of lingunite in shocked chondritic meteorites

PHYSICS OF THE EARTH AND PLANETARY INTERIORS
  • Tomoaki Kubo
  • ,
  • Mari Kono
  • ,
  • Masahiro Imamura
  • ,
  • Takumi Kato
  • ,
  • Seiichiro Uehara
  • ,
  • Tadashi Kondo
  • ,
  • Yuji Higo
  • ,
  • Yoshinori Tange
  • ,
  • Takumi Kikegawa

272
開始ページ
50
終了ページ
57
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1016/j.pepi.2017.09.006
出版者・発行元
ELSEVIER SCIENCE BV

We conducted high-pressure experiments in plagioclase with different anorthite contents at 18-27 GPa and 25-1750 degrees C using both a laser-heated diamond anvil cell and a Kawai-type multi-anvil apparatus to clarify the formation conditions of the hollandite phase in shocked chondritic and Martian meteorites. Lingunite (NaAlSi3O8-rich hollandite) was found first to crystallize from amorphous oligoclase as a metastable phase before decomposing into the final stable state. This process might account for the origin of lingunite found along with maskelynite in shocked chondritic meteorites. Metastable lingunite appeared at similar to 20-24 GPa and similar to 1100-1300 degrees C in laboratory tests lasting tens of minutes; however, it might also form at the higher temperatures and shorter time periods of shock events. In contrast, the hollandite phase was not observed during any stage of crystallization when using albite or labradorite as starting materials. The formation process of (Ca,Na)-hollandite in the labradorite composition found in Martian shergottites remains unresolved. The orthoclase contents of the hollandite phase both in shocked meteorites (2.4-8.2 mol%) and our oligoclase sample (3.9 mol %) are relatively high compared to the albite and labradorite samples (0.6 and 1.9 mol%, respectively). This might critically affect the crystallization kinetics of hollandite phase.

Web of Science ® 被引用回数 : 1

リンク情報
DOI
https://doi.org/10.1016/j.pepi.2017.09.006
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000415773900006&DestApp=WOS_CPL