When did James Hutton made his discovery?

James Hutton made his significant discoveries in the late 18th century, with his most notable work published in 1788 in "Theory of the Earth." He introduced the concept of deep time and the idea that the Earth is shaped by continuous processes over long periods, laying the groundwork for modern geology. His observations of rock formations and sedimentation patterns helped establish the principle of uniformitarianism, which posits that the processes we observe today have operated in much the same way throughout Earth's history.