Science / Geology / A-Horizon: The uppermost layer of a soil, containing organic material and leached minerals.
Science / Geology / Pedocal: A common soil type of arid regions, characterized by accumulation of calcium carbonate in the A-horizon. MORE
Science / Geology / B-Horizon: The intermediate layer in a soil, situated below the A-horizon and consisting of clays and oxides. Also called the zone of accumulation. MORE