-
100
4600 million years ago
Earth was formed by a collisions in a gaint disc -shaped cloud of material -
100
4600 million years ago
The rain of rocks and asteroids is never ending and the rocks that do form from cooling lavas are quickly buried under new lava flows or blasted to bits by yet another impact! -
100
4280 million years ago
The oldest rocks, the faux amphibolites, of the greenstone belt in Quebec, Canada are formed. -
100
4600 million years ago
The evolution of the isotopes of lead-207 and lead-206 is studied from several lead deposits of different age on Earth, including oceanic sediments that represent a homogenized sample of Earth’s lead. -
100
4600 million years ago
A minimum of 500 to 1,000 impact basins were formed on Eart. -
100
4600 million years ago
The earliest thin crust was probably unstable and so foundered and collapsed to depth. -
100
4600 million years ago
Particles in the solar nebula condensed to form solid grains, and with increasing electrostatic and gravitational influences they eventually clumped together into fragments or chunks of rock -
100
4600 million years ago
Rapid recycling of crust–mantle material occurred in convection cells, and in this way the earliest terrestrial continents may have evolved during the 300-million-year gap between the formation of Earth and the beginning of the rock record. -
200
3600 million years ago
Algae is the only living thing, and will later be found in some of the oldest fossils from this time period -
200
3600 million years ago
When the surface of Earth had cooled to below 100 °C (212 °F), the hot water vapour in the atmosphere would have condensed to form the early oceans. -
200
3600 million years ago
Plate tectonics were formed. -
200
3500 million years ago
Archean rocks are formed. -
200
3500 million years ago
Occasionally the small islands collide with each other to form larger islands. Eventually these larger islands will collide to form the cores of the continents we know today. -
200
3500 million years ago
The volcanoes form lots of small islands in long chains. The islands are the only land surface. -
200
3500 million years ago
Most water vapor in the air has cooled and condensed to form a global ocean. -
200
3500 million years ago
Most of the carbon dioxide is gone, having been chemically changed into limestone and deposited at the bottom of the ocean. -
300
2600 million years ago
Two super continents were formed from collisions of many islands. -
300
2600 million years ago
Free oxygen released by the algae floating in the oceans is beginning to collect in the air. -
300
2200 million years ago
Several pieces of evidence — the presence of iron oxides in paleosols (fossil soils), the appearance of "red beds" containing metal oxides, and others — point to a fairly rapid increase in levels of oxygen in the atmosphere at about this time. -
300
2300 million years ago
Megascopic eukaryotes first appeared. -
300
2100 million years ago
The breakup of this landmass is indicated by the intrusion of abundant transcontinental swarms of dolerite (a type of fine-grained igneous rock) dikes. These dikes resulted from the impingement of mantle plumes onto the base of the continental crust. This was the fundamental cause of the breakup of the initial supercontinent. -
300
2100 million years ago
Many mountain belts formed and new ocean basins were created by the rifting apart of the continents. -
300
2600 million years ago
Life is still found only in the ocean. -
300
2600 million years ago
Until now the oxygen has been combining chemically with iron and other elements to form great mineral deposits around the world. Paradoxically, this oxygen, which we must have to live, is poisonous to most of the life forms living on Earth during the Proterozoic. -
400
1500 million years ago
Earth's inner core was formed. -
400
1500 million years ago
The eukaryotes divide into three groups: the ancestors of modern plants, fungi and animals split into separate lineages, and evolve separately. -
400
900 million years ago
The first multicellular life develops. -
400
800 million years ago
The early multicellular animals undergo their first splits. First they divide into, essentially, the sponges and everything else – the latter being more formally known as the Eumetazoa. -
400
770 million years ago
The planet freezes over again in another “snowball Earth“. -
400
730 million years ago
The comb jellies (ctenophores) split from the other multicellular animals. Like the cnidarians that will soon follow, they rely on water flowing through their body cavities to acquire oxygen and food. -
400
680 million years ago
The ancestor of cnidarians (jellyfish and their relatives) breaks away from the other animals – though there is as yet no fossil evidence of what it looks like. -
400
630 million years ago
Around this time, some animals evolve bilateral symmetry for the first time: that is, they now have a defined top and bottom, as well as a front and back. Little is known about how this happened. However, small worms called Acoela may be the closest surviving relatives of the first ever bilateral animal. It seems likely that the first bilateral animal was a kind of worm. Vernanimalcula guizhouena, which dates from around 600 million years ago, may be the earliest bilateral animal found in the f