Timeline of geology: see also geologic timescale.

• 1620 - Francis Bacon notices the jigsaw fit of the opposite shores of the Atlantic Ocean
• 1701 - Edmund Halley suggests using the salinity and evaporation of the Mediterranean to determine the age of the Earth
• 1785 - James Hutton presents paper entitled Theory of the Earth - earth must be old
• 1830 - Sir Charles Lyell publishes book, Principles of Geology
• 1837 - Louis Agassiz begins his glaciation studies which eventually demonstrate that the Earth has had at least one Ice Age
• 1862 - Lord Kelvin attempts to find the age of the Earth by examining its cooling time and estimates that the Earth is between 20--400 million years old
• 1903 - George Darwin and John Joly claim that radioactivity is partially responsible for the Earth's heat
• 1907 - Bertram Boltwood proposes that the amount of lead in uranium and thorium ores might be used to determine the Earth's age and crudely dates some rocks to have ages between 410--2200 million years
• 1912 - Alfred Wegener proposes that all the continents once formed a single landmass called Pangaea that broke apart via continental drift
• 1913 - Albert Michelson measures tides in the solid body of the Earth
• 1935 - Charles Richter invents a logarithmic scale to measure the intensity of earthquakes
• 1953 - Maurice Ewing and Bruce Heezen discover the Great Global Rift running along the Mid-Atlantic Ridge
• 1960 - Harry Hess proposes that new sea floor might be created at mid-ocean rifts and destroyed at deep sea trenches
• 1963 - F.J. Vine and D.H. Matthews explain the stripes of magnetized rocks with alternating magnetic polarities running parallel to mid- ocean ridges as due to sea floor spreading and the periodic geomagnetic field reversals