"Unfortunately, we haven't found many very old rocks on Earth because our planet's surface is constantly renewed by plate tectonics, coupled with erosion"

This quote by Robert Duncan is referring to the reality that Earth's surface area is constantly being renewed by plate tectonics and disintegration. This suggests that the surface of the Earth is constantly changing, and as a result, it is difficult to discover very old rocks on the planet. Plate tectonics is the procedure by which the Earth's crust is burglarized big pieces, which then move and interact with each other. Erosion is the process by which the Earth's surface area is worn away by wind, water, and other natural forces. Together, these two processes are constantly reshaping the Earth's surface area, making it hard to discover older rocks. This quote highlights the value of plate tectonics and erosion in forming the Earth's surface, and how they make it tough to find older rocks.