noun
schistosity
Geological term referring to the planar fabric in schistose rocks, where platy minerals are aligned.
この地域の結晶片岩には明瞭な片理が発達している。
The crystalline schist in this area exhibits well-developed schistosity.
Compound of 片 (へん, 'piece' or 'one-sided') and 理 (り, 'texture' or 'grain'), referring to the directional fabric in schist. The exact historical derivation is uncertain, but the term is a standard geological calque.