What ideas about the age of Earth did James Hutton develop?

James Hutton challenged the prevailing 18th-century belief that the Earth was only about 6,000 years old, a figure derived from biblical interpretations. Instead, he proposed that the Earth is a dynamic, ever-changing system governed by cyclical processes.12

Hutton developed the principle of uniformitarianism, which posits that the same natural processes observed today—such as erosion, sedimentation, and volcanism—have operated with general uniformity throughout geologic time. He argued that land surfaces are continuously worn down by erosion and subsequently renewed through subterranean heat-generated processes that uplift new rock.12

Because these cycles of destruction and restoration occur over immense spans of time, Hutton concluded that the age of the Earth must be "inconceivably great". His work, most notably presented in his two-volume Theory of the Earth, shifted geology away from catastrophist and Neptunist dogmas, establishing a foundation for modern scientific understanding of the planet's history.12