Who first proposed that each layer of rock represented a specific interval of geologic time?

The concept that each layer of rock represents a specific interval of geologic time was first proposed by the Scottish geologist James Hutton in the late 18th century. Hutton is often referred to as the "father of modern geology" for his theory of uniformitarianism, which posits that the processes shaping the Earth today have been consistent over time. His ideas laid the groundwork for understanding the geological time scale and the significance of rock layers in studying Earth's history.