1 Ch.3, Sec.1 – Earth’s Story & Those Who First ListenedThe Principle of Uniformitarianism - James Hutton, a Scottish scientist, was the founder of modern geology, based upon his research in 1788 - Hutton observed that processes we observe today, like erosion & deposition, remain uniform over time - his idea, uniformitarianism, states that geologic processes that occurred in the past can be explained by current geologic processes - in the 1700s, people believed the Earth was thousands of years old, not millions, which is what Hutton believed

2 Ch.3, Sec.1 – Earth’s Story & Those Who First Listened

3 Ch.3, Sec.1 – Earth’s Story & Those Who First Listened- Hutton observed layers of rocks that were vertical & horizontal at Siccar Point in Scotland - Siccar Point would have taken millions of years to have formed, not thousands which is what was stated in religious scriptures - most scientists at the time supported the idea of catastrophism, which is a principle that states that geologic change occurs suddenly - supporters of catastrophism believed all geologic landforms were created by catastrophes very quickly, not slowly

4 Ch.3, Sec.1 – Earth’s Story & Those Who First Listened- in the 1830s, British geologist Charles Lyell reintroduced more evidence to show support for uniformitarianism Modern Geology – A Happy Medium - scientists now believe that both theories have played a role in geologic processes, with most coming very slowly - huge craters have been found all over Earth to help support the idea of catastrophism affecting geological processes and possibly killing all of the dinosaurs 65mya

5 Ch.3, Sec.1 – Earth’s Story & Those Who First ListenedBarrington Crater in Arizona

6 Ch.3, Sec.1 – Earth’s Story & Those Who First Listened- dinosaur extinction is a good example of catastrophism Chicxulub Crater, Mexico

7 Ch.3, Sec.1 – Earth’s Story & Those Who First ListenedPaleontology – The Study of Past Life - the history of the Earth would be incomplete without a knowledge of all of the organisms that have lived on the planet - the science involved with the study of past life is called paleontology - paleontologists study fossils of animal remains & paleobotanists study fossils of plants