<human>:  I have a question about Geology and Stratigraphy. Who was the first person to propose the theory of the rock cycle?
<bot>: The first person to propose the theory of the rock cycle was Charles Lyell. Lyell was a British geologist who lived from 1797 to 1875. He was a proponent of uniformitarianism, which is the idea that the present is the key to understanding the past. Lyell proposed that the Earth was formed by a process of gradual change over time, and that the present is the key to understanding the past.