Chapter 12, Problem 1FQ

To determine

The reason why some exposed parts of the boulder are darker than others.

Answer to Problem 1FQ

The darker areas may have undergone weathering and thereby generate new, darker compounds such as iron oxides, while the lighter areas are exposed to the surface more recently following the removal of weathered products.

Explanation of Solution

Weathering can be defined as the process that involves the breakdown of rock material into smaller particles at or near the surface of the Earth. The process of weathering takes place when a rock is exposed to an environmental condition that supports weathering. It can be a change in pressure, temperature, or substances mainly water. As a result of weathering, the rocks are weakened and broken. These broken particles are known as clasts, and it can be small or large. Continuous weathering that takes place on detached fragments breaks them into smaller particles, and thus they become susceptible to other exogenic processes such as erosion, transportation, and deposition.

Some of the exposed parts of boulders are darker than others due to the fact that the areas have undergone weathering, and new, darker compounds such as iron oxides are formed. The lighter areas are the parts of boulders that are exposed to the surface recently after the removal of weathered products.