In several sections, both natural in the banks of the Mississippi and its numerous arms, and where artificial canals had been cut, I observed erect stumps of trees, with their roots attached, buried in strata at different heights, one over the other.

Life Letters and Journals of Sir Charles Lyell 1. One of the contributions that Lyell made in Principles was to explain the cause of earthquakes. Both Whewell and Sedgwick wrote worried letters to him about this.

Lyell was a close and influential friend of Charles Darwin. He is best known as the author of Principles of Geology which popularised James Hutton's concepts of uniformitarianism – the idea that the earth was shaped by the same processes still in operation today.