James Hutton proposed a process called the Rock Cycle to explain how rocks on Earth's surface are replenished. This cycle is a continuous process of transformation where rocks are:

1. Formed: Magma deep within the Earth cools and solidifies to form igneous rocks.

2. Weathered and Eroded: Igneous rocks are exposed to the surface and broken down by weathering and erosion. This creates sediments.

3. Transported and Deposited: Sediments are transported by wind, water, or ice and deposited in new locations.

4. Compacted and Cemented: Layers of sediments are buried and compacted under pressure, eventually forming sedimentary rocks.

5. Metamorphosed: Sediments or igneous rocks are subjected to intense heat and pressure, transforming them into metamorphic rocks.

6. Re-melted: Metamorphic rocks, sedimentary rocks, or igneous rocks can be re-melted back into magma, completing the cycle.

Hutton's theory, known as uniformitarianism, stated that the processes that shape the Earth today are the same processes that have been operating for millions of years. This understanding was revolutionary, as it challenged the prevailing idea of a young Earth with sudden, catastrophic events.

Hutton's Rock Cycle model provides a framework for understanding the dynamic nature of Earth's crust and its constant renewal.