comminution
comminution
The gradual diminution of a substance to a fine powder or dust by crushing, grinding, or rubbing; specif., the reduction of a rock to progressively smaller particles by weathering, erosion, or tectonic movements.
The breaking, crushing, or grinding by mechanical means of stone, coal, or ore, for direct use or further processing.
White, finely-ground rock material (rock-flour) characteristic of burst fractures. May be indicative of secondary movement on induced fractures.