noun
Geological term for an unconsolidated, lime-rich sedimentary rock. Used in earth science contexts.
この地域の地層には泥灰岩が多く含まれている。
The strata in this area contain a lot of marl.
Compound of 泥 (mud), 灰 (ash/lime), and 岩 (rock), describing its composition. The exact historical derivation is uncertain.