B horizon

noun

, Geology.

1. the subsoil in a soil profile.

B horizon

noun

1. the layer of a soil profile immediately below the A horizon, containing deposits of leached material

B horizon

1. In ABC soil, the second and middle zone, characterized by an accumulation of soluble or suspended organic material, clay, iron, or aluminum. These materials originate in the A horizon and are transported to the B horizon through the process of eluviation. B horizons often have a blocky structure and are reddish in color due to the presence of oxidized metals.
2. Also called zone of accumulation zone of illuviation

Word History and Origins

Origin of B horizon¹

First recorded in 1935–40

Example Sentences

He had dug the trenches for the footing and got down to the B horizon in the soil where there was no organic material.

From Seattle Times