What did Charles Darwin observe about earthquakes and rising land in Chile?

During his voyage on the HMS Beagle, Charles Darwin observed significant evidence of geological change in Chile that supported the uniformitarian theories of Charles Lyell.

In February 1835, while in Valdivia, Chile, Darwin experienced a powerful earthquake that caused widespread destruction in the city of Concepción. Following this event, he observed that beds of mussel shells, which had previously been underwater, were now lying above the high-tide mark. This provided him with tangible proof that the land had been physically thrust upward by the seismic activity.

Darwin concluded that the continent was rising through steady, cumulative forces—a process he had also inferred from finding fossilized trees at high elevations in the Andes Mountains. These observations were instrumental in helping him develop a sense of "deep time" regarding the Earth's geological history.1