-
Earth was formed by a collisions in a gaint disc -shaped cloud of material
-
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!
-
The oldest rocks, the faux amphibolites, of the greenstone belt in Quebec, Canada are formed.
-
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.
-
A minimum of 500 to 1,000 impact basins were formed on Eart.
-
The earliest thin crust was probably unstable and so foundered and collapsed to depth.
-
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
-
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.
-
Algae is the only living thing, and will later be found in some of the oldest fossils from this time period
-
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.
-
Plate tectonics were formed.
-
Archean rocks are formed.
-
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.
-
The volcanoes form lots of small islands in long chains. The islands are the only land surface.
-
Most water vapor in the air has cooled and condensed to form a global ocean.
-
Most of the carbon dioxide is gone, having been chemically changed into limestone and deposited at the bottom of the ocean.
-
Two super continents were formed from collisions of many islands.
-
Free oxygen released by the algae floating in the oceans is beginning to collect in the air.
-
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.
-
Megascopic eukaryotes first appeared.
-
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.
-
Many mountain belts formed and new ocean basins were created by the rifting apart of the continents.
-
Life is still found only in the ocean.
-
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.
-
Earth's inner core was formed.
-
The eukaryotes divide into three groups: the ancestors of modern plants, fungi and animals split into separate lineages, and evolve separately.
-
The first multicellular life develops.
-
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.
-
The planet freezes over again in another “snowball Earth“.
-
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.
-
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.
-
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