Brazil, W. Indies, tropical Africa, South India, forested warm temperate and tropical regions. These regions have alternate wet and dry period, and hot humid conditions.
1. Extreme form of red tropical soil type.
2. Leached of alkalis and silica.
3. Accumulation of sesquioxides in top layer.
4. Crust formation near the surface, nodular concretions, induration
5. When dry it becomes hard and thus forms a useful building material.
6. Soil reaction is acidic.
7. Poor base saturation.