- 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
Timeline of Geology
