Granite weathering in a temperate semi-arid climate most commonly yields what sediment?

Granite weathering in a temperate semi-arid climate most commonly yields what sediment?

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

Answer: (C)

Granite, being quartz-rich and fairly resistant, tends to break down into sand-sized, quartz-dominated material when weathering proceeds in climates where moisture is limited. In a temperate semi-arid setting, mechanical weathering and limited chemical weathering prevail because rainfall is not abundant enough to drive extensive hydrolysis of feldspar to clay. As a result, the feldspar and other minerals from granite weather slowly, and the most persistent, transportable product is sand-sized quartz grains that can accumulate as sand. Fine clay from feldspar hydration would require more chemical weathering than this climate typically provides, and gravel would come from larger fragments rather than the steady production of sand-sized particles. Thus, the sediment most commonly produced is sand.

Granite, being quartz-rich and fairly resistant, tends to break down into sand-sized, quartz-dominated material when weathering proceeds in climates where moisture is limited. In a temperate semi-arid setting, mechanical weathering and limited chemical weathering prevail because rainfall is not abundant enough to drive extensive hydrolysis of feldspar to clay. As a result, the feldspar and other minerals from granite weather slowly, and the most persistent, transportable product is sand-sized quartz grains that can accumulate as sand. Fine clay from feldspar hydration would require more chemical weathering than this climate typically provides, and gravel would come from larger fragments rather than the steady production of sand-sized particles. Thus, the sediment most commonly produced is sand.