Answer: The model is depicting the glacier erosion.
Step-by-step explanation:
The glaciers are responsible for causing erosion of the earth. They transport the materials away from the locations were they are earlier situated. They carve the materials present beneath the land. They erode the materials like soil, pebbles, boulders, against the pressure of the unstable mass of the ice moving down the slope. The broken ice mass carriers away the broken rocks, materials and soil debris far away from the places where they have been originally situated. This causes the glacial erosion. Also the broken and displaced rocks displace the soil and other materials come in contact with during erosion.
According to the given situation, the ice formed with water only had no impact on the tinfoil on the other hand the ice containing the sand and rocks removed the tinfoil from places. This is because of the friction created by the sand and rocks on the tinfoil. The glacier material like ice, soil, rocks due to friction erode the material come in contact with it with an appreciable pressure underneath.