Lyell's theories like Darwin's were somewhat controversial during the 1800's. He studied in geology and his main thoughts about it were:

• The earth was older than a few thousand years, maybe even billions of years old.
• The earth is always in motion.
• The changes in land masses explained earth's geology rather than sea level changes.

Darwin read Lyell's book Principles of Geology-Vol. 1 during his trip on the H.M.S. Beagle. He then later on met Lyell and he influenced Darwin to publish his theories even though, he himself was skeptical.

     Hutton's main theory of geology was uniformitarianism (which is the laws of nature as they are now having always been in operation). He also believed the earth to be very old. That some of the mountain ranges have been pushed off the sea floor. He believed that sedimentation and erosion had a lot to do with the geology we have today.