In a temperate semi-arid environment, granite would weather to which sediment type?

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

Answer: (C)

In this climate, physical, not chemical, weathering dominates. The temperate semi-arid environment has limited rainfall, so chemical reactions that would turn feldspar and other minerals into clays proceed slowly. Granite breaks primarily along existing joints and through freeze-thaw and mechanical abrasion, producing angular particles that are typically in the sand size range. The quartz and resistant minerals persist as sand-sized grains, while the limited water slows the chemical transformation of feldspar to clay. Also, fine particles can be removed by wind or water more readily in arid conditions, leaving a sandy sediment. Larger clasts (gravel) aren’t as common because continued mechanical breakdown tends to reduce material to sand rather than keeping or producing large chunks. Thus, the primary sediment resulting from granite weathering in a temperate semi-arid setting is sand.