論文

査読有り
2017年4月

Microstructural observations of fracture-filling goethite vein along the Kerajang Fault Zone in the Rengali Province of eastern India

JOURNAL OF MINERALOGICAL AND PETROLOGICAL SCIENCES
  • Takafumi Yamamoto
  • ,
  • Jun-ichi Ando
  • ,
  • Naotaka Tomioka
  • ,
  • Kaushik Das
  • ,
  • Gautam Ghosh
  • ,
  • Sankar Bose

112
2
開始ページ
102
終了ページ
107
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.2465/jmps.161113
出版者・発行元
JAPAN ASSOC MINERALOGICAL SCIENCES

Microstructural observations and chemical composition analyses of a fracture-filling goethite vein in quartzite bands adjacent to a terrain-boundary fault zone were carried out, primarily using electron microscopy, to determine its formation process. Two domains A and B were identified, based on microstructural and chemical characteristics. The domain A formed a layered structure characterized by goethite grains with higher Al contents, smaller grain size (several hundred nanometers to micrometers in size), with development of the strong shape-and lattice-preferred orientations (SPO and LPO) of [020] and [110] along the wall rock contact, whereas the inner region had lower Al contents with larger grain size (several micrometers in size). The domain B exhibited concentric zoning characterized by variation in chemical composition, grain-size grading approximately ten to several tens of nanometers in size, a change in the porosity, and the alignment of goethite [110] perpendicular to the zoning plane. The grain size distribution and development of SPO and LPO in domain A can be explained by the inhibition of crystal growth (due to the incorporation of Al3+ instead of Fe3+) and geometrical selection, respectively. Two possible formation processes for domain B can be proposed based on the analogy of chalcedony; precipitation of goethite colloidal particles with electrophoretic force or heterogeneous nucleation from the Fe-rich supersaturated fluid and subsequent crystal growth. The study results suggest that the goethite vein was formed by multiple stages of Fe-rich fluid infiltration, which may have been derived from the Banded Iron Formation in the Singhbhum cratonic crust related to the activation of the Kerajang Fault Zone.

Web of Science ® 被引用回数 : 1

リンク情報
DOI
https://doi.org/10.2465/jmps.161113
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000404489400005&DestApp=WOS_CPL

エクスポート
BibTeX RIS