noun
fine particle fraction; fines
Technical term used in soil mechanics, sedimentology, and materials science for the portion of a granular material consisting of particles smaller than a specified size (often silt and clay).
この土の細粒分は主にシルトと粘土からなる。
The fine particle fraction of this soil consists mainly of silt and clay.
細粒分の含有
A high content of fines reduces the permeability of the soil.