Some famous geologists in history include Eratosthenes, James Hutton, Sir Charles Lyell, Mary Anning and Alfred Wegener. Others include Gene Shoemaker, William Smith, Friedrich Mohs and Inge Lehmann.
Eratosthenes was a Greek mathematician, geologist, geographer and astronomer who lived more than 2,200 years ago. He is most famous for his work in calculating the circumference of the Earth by using geometry and measuring distances in northern Africa. He invented the discipline of geography and scientific chronology.
James Hutton is known as the father of geology, mainly for being the first to theorize that the Earth was much older than had been previously thought. His theories provided a basis for a great deal of important work that followed in other fields, such as biology, geology and evolutionary science.
James Lyell was a Scottish geologist whose seminal work, "Principles of Geology," published in 1830, built on and popularized the work of James Hutton. Mary Anning is sometimes called the greatest fossilist in history, mainly for her research with dinosaur fossils in Britain during the 19th century. James Wegener is famous for his theory that the Earth's continents were once joined in a single protocontinent which he called Pangaea, a theory that formed a basis for modern plate tectonics.