-
Abū Rayhān al-Bīrūnī publishes the Kitāb fī Taḥqīq mā li-l-Hind, which he discusses the geology of India and hypothesizes that it was once a sea.
-
Abraham Ortelius, Flemish-Spanish cartographer, promotes the continental drift theory.
-
Nicolas Steno puts forward his theory that sedimentary strata had been deposited in former seas, and that fossils were organic in origin.
-
Edmond Halley suggests using evaporation from Mediterranean to determine the age of the Earth.
-
James Keir suggests that some rocks, like the ones at the Giant's Causeway, might have been formed by the crystallisation of molten lava.
-
Sir Charles Lyell publishes book, Principles of Geology, which describes the world as being several hundred million years old.
-
Louis Agassiz begins his glaciation studies which eventually demonstrate that the Earth has had at least one ice age.
-
George Darwin and John Joly claim that radioactivity is partially responsible for the Earth's heat.
-
Arthur Holmes uses radioactivity to date rocks, the oldest being 1.6 billion years old.
-
Physicist Luis Alvarez, and his son Walter Alvarez, and others propose that the impact of a large extraterrestrial object caused the extinction of the dinosaurs at the end of the Cretaceous Period, about 66 million years ago.
