rock flour

noun

1. glacial meal.

rock flour

noun

1. very finely powdered rock, produced when rocks are ground together (as along the faces of a moving fault or during the motion of glaciers) and are thus chemically unweathered

Word History and Origins

Origin of rock flour¹

First recorded in 1880–85

Example Sentences

Nearly all of the soil in the Park is rock-flour that was ground by glaciers, and in part distributed by them.

From Project Gutenberg

The product of plucking is bowlders, while the product of abrasion is fine rock flour and sand.

From Project Gutenberg

Mountains were moved piecemeal, and ground to boulders, pebbles, and rock-flour in the moving.

From Project Gutenberg

Indeed the resemblance is so close that the clay produced by this grinding action is often called rock flour.

From Project Gutenberg

Mountains are moved piecemeal, and are ground to boulders, pebbles, and rock-flour in the moving.

From Project Gutenberg