Michigan Test for Teacher Certification (MTTC) Secondary Integrated Science Practice test

Which of the following soils is particularly rich in iron and aluminium oxide?

1. Laterites

2. Pedalfers

3. Pedocals

4. Aquifers

The correct answer is: Laterites

Laterites are soils that form in hot, humid tropical regions and are characterized by their high content of iron and aluminum oxides. The weathering process in these regions causes leaching of silica and other soluble minerals, leaving behind these oxides, which gives laterites a distinctive reddish color. This composition makes laterites particularly valuable for certain agricultural practices, as the iron and aluminum can influence soil fertility and behavior. In contrast, pedalfers generally contain more clay and are rich in minerals and nutrients, making them different in composition. Pedocals, often found in drier regions, have a higher calcium carbonate content rather than iron and aluminum oxides. Aquifers, being underground layers of water-bearing rock or sediment, do not refer to soil types at all, and thus do not contain iron and aluminum oxide. Each of these other categories represents different environmental conditions and formations, which is why laterites stand out due to their unique richness in iron and aluminum oxides.