请输入您要查询的字词:

 

单词 foid
释义
foid

Geology and Earth Sciences
  • A contraction of the term feldspathoid, which is applied to any plutonic rock containing up to 60% modal feldspathoid minerals. For example, a syenite with significant nepheline present can be termed a ‘foid-bearing syenite’, or a ‘foid-syenite’. Such terminology is used on the Streckeisen classification of igneous rocks with a colour index of less than 90. In practice, the terms ‘foid-bearing’ and ‘foid-’ are replaced with the specific feldspathoid mineral name. In the above example, the name ‘nepheline-syenite’ would apply. Where the modal volume of feldspathoid minerals exceeds 60%, the rock is termed a ‘foidolite’.


随便看

 

科学参考收录了60776条科技类词条,基本涵盖了常见科技类参考文献及英语词汇的翻译,是科学学习和研究的有利工具。

 

Copyright © 2000-2023 Sciref.net All Rights Reserved
京ICP备2021023879号 更新时间:2025/3/10 7:00:45