1669 - The geological laws
1812 - Properties of minerals
1830 - Geology occurs by natural processes
1833 - The three types of rocks - igneous, sedimentary and metamorphic
1837 - A past Ice Age is theorized
1907 - Radioactive decay is used to date the earth
1912 - Aflred Wegener proposes continental drift theory
1972 - Ancient life and the fossil record.