Look at the photo. There is a canyon with water flowing through it. Over thousands of years, the water has caused chemical weathering. Identify and describe two possible processes that change the rocks in the canyon.
• Freezing and melting cycles
Water that has mixed with carbon dioxide to form carbonic acid, dissolving minerals in the rocks, and oxidation causing chemical weathering when oxygen combines with iron in the rocks, forming rust and causing them to break down
Erosion by animals and precipitation
Wind abrasion and volcanic activitiy
Water flowing through the canyon can cause two processes of chemical weathering: freezing and melting cycles, and water mixing with carbon dioxide to form carbonic acid.
1. Freezing and melting cycles: When water seeps into cracks and crevices in the rocks of the canyon, it can freeze and expand during cold temperatures. This expansion exerts pressure on the surrounding rock, causing it to break apart. When the ice melts, it further weakens the rock structure, leading to the gradual breakdown of the rocks over time.
2. Water mixing with carbon dioxide: Water that flows through the canyon can dissolve carbon dioxide from the surrounding air, forming carbonic acid. This weak acid can react with minerals present in the rocks, causing them to dissolve and break down. This process is especially effective on rocks containing calcium carbonate, such as limestone, which can be gradually eroded away by the carbonic acid.
It's worth noting that while erosion by animals and precipitation, wind abrasion, and volcanic activity can contribute to the overall erosion of the canyon, they are not processes of chemical weathering.