Organic,slightly decomposed Organic,moderately decomposed Organic,highly decomposed A Mineral,mixed with humus,dark colored E Horizon of maximum leaching of silicate clays,Fe,Al oxides,etc. B Zone of Fe and Al accumulation Zone of least weathering and accumulation contains unweathered parent material R Generic soil Bedrock profile2024/8/22 自然地理学 8 Generic soil profile