Explain how the texture of a rock surface affects how fast it physically weathers by water.(4 points)
1. Surface roughness: A rough surface will have a greater surface area compared to a smooth surface. This means that there will be more exposed areas for water to come into contact with. As a result, the rough surface will be more susceptible to physical weathering by water as the water can penetrate into the cracks and crevices of the rock more easily.
2. Porosity: The porosity of a rock determines how much water can be absorbed by it. A high-porosity rock will have more open spaces, such as pores and fractures, where water can enter. This can lead to increased physical weathering as the water enters the rock and exerts pressure on its internal structure, causing it to weaken and break apart more easily.
3. Permeability: Permeability refers to the ability of a rock to allow water to pass through it. A rock with high permeability will allow water to flow more freely through its pores and fractures, increasing the chances of physical weathering. This is because the water can exert pressure on the rock from within, leading to the expansion and contraction of the rock material, eventually causing it to crumble or break apart.
4. Mineral composition: The mineral composition of a rock can also affect its physical weathering by water. Some minerals may be more susceptible to dissolution or chemical reactions with water, leading to their alteration or breakdown. This can weaken the rock structure and make it more prone to physical weathering. Additionally, some minerals may be more resistant to weathering and remain intact despite being exposed to water, thus reducing the overall rate of physical weathering.