In a temperate semi-arid environment, the weathering of granite most commonly produces which sediment size?

• A. Clay
• B. Sand
• C. Silt
• D. Gravel

Answer: (B)

In a temperate semi-arid setting, physical weathering dominates because there isn’t enough moisture for intense chemical alteration. Granite is coarse-grained and breaks down into fragments, with quartz, the most resistant mineral, persisting as the principal surviving grains. Feldspar and other minerals tend to weather chemically to clays only with more water, which is limited here, so clay production is suppressed. The net result is a prevalence of sand-sized grains: quartz-rich material disintegrated from granite that can be carried and deposited as sand rather than forming abundant clay or silt, and not typically as large gravel. So the most common sediment size produced by weathering of granite in this environment is sand.