Which process is primarily concerned with breaking down rocks and minerals?

The process primarily concerned with breaking down rocks and minerals is weathering. Weathering involves the physical, chemical, or biological alteration of rocks and minerals at or near the Earth's surface. This process can occur through a variety of mechanisms, such as temperature changes causing expansion and contraction, the action of water and ice causing physical breakdown, or chemical reactions that change the composition of the rock.

Understanding weathering is crucial because it contributes significantly to soil formation and the cycling of nutrients, which impacts ecosystems. Other processes, such as erosion, transportation, and deposition, relate to how materials are moved or deposited rather than the breaking down of rocks and minerals themselves. Erosion refers to the removal and transport of weathered materials, while transportation deals with the movement of these materials from one location to another. Deposition is the final step where the eroded sediments settle in a new location, rather than breaking down the rocks.