Which geologist studied rock layering (stratigraphy) and advocated uniformitarianism?

• A. James Hutton
• B. Charles Lyell
• C. Georges Cuvier
• D. Louis Agassiz

Answer: (A)

Stratigraphy—reading Earth's history through rock layers—is best connected to the idea that the same natural processes we see today have always shaped the planet, just acting over immense timescales. James Hutton studied rock layering in Scotland and argued that Earth's features result from gradual processes like sediment deposition, uplift, and erosion operating over very long periods. From this, he formulated uniformitarianism: the present is the key to the past, meaning the same forces we observe now have been at work throughout Earth's history. While others like Charles Lyell later popularized and expanded this view, Hutton is the geologist who first linked visible layering with the long, slow processes that shape the world. The other figures represent different viewpoints—some emphasizing sudden catastrophes or specific phenomena like ice ages—but they don’t align as directly with both stratigraphy and this gradualist perspective.