480.00 MILLION YEARS AGO - 440.00 MILLION YEARS AGO : Iapetus Ocean

Iapetus Ocean

        The Iapetus Ocean forms to the south of the Laurasian continent. It closes up as the Baltica continent and adjacent arc of volcanic islands move northward to collide with Laurasia.

480.00 MILLION YEARS AGO - 440.00 MILLION YEARS AGO : Famatinian Orogeny

Famatinian Orogeny

The Famatinian orogeny (mountain-building episode) produces the Sierra de Famatina, a spur of the Andes Mountains in South America. It is the result of a collision between Argentina and the Laurasian landmass.

520.00 MILLION YEARS AGO - 510.00 MILLION YEARS AGO : Marine Species Dwindle

Marine Species Dwindle

Two major extinction events occur within the Cambrian Period that severely reduce the size of algae populations and the number of trilobite species. By the end of the Cambrian Period, trilobites are no longer the dominant marine animals.

Tribolite

525.00 MILLION YEARS AGO - 515.00 MILLION YEARS AGO : Antrim Plateau Forms

Antrim Plateau Forms

        The Antrim Plateau in northwestern Australia forms from flood basalts, layers of cooled lava built up gradually by repeated outpourings from fissures in the ground. 

530.00 MILLION YEARS AGO : Animals Preserved in Burgess Shale

Animals Preserved in Burgess Shale

        Very unusual soft-bodied animals, including trilobites and other marine invertebrates, are buried under ocean sediment and preserved in a fossil bed in Canada known as the Burgess Shale.

540.00 MILLION YEARS AGO : Chengjiang Animals Flourish

Chengjiang Animals Flourish

        The first soft-bodied animals of the Phanerozoic Eon include a wide variety of marine invertebrates, some of which are large predators. Fossils of these animals have been found near Chengjiang in Yunnan, southern China.

550.00 MILLION YEARS AGO : Gondwanaland Forms

Gondwanaland Forms

        Continents in the southern hemisphere move together to form a single landmass near the south pole. This landmass is called Gondwanaland. 

        Gondwanaland, ancient landmass that consisted of the present continents of South America, Africa, Australia, and Antarctica as well as the Indian subcontinent. Gondwanaland is believed to have been intact at least twice, about 350 million years ago and about 200 million years ago. Between these two periods all seven of the present-day continents probably formed a single landmass called Pangaea. 

570.00 MILLION YEARS AGO : Phanerozoic Eon Begins

Phanerozoic Eon Begins

        The Phanerozoic Eon begins with rising ocean levels and the breakup of the supercontinent Rodinia. A northern landmass called Laurentia forms near the equator. Plate tectonics continues to increase the volume and area of the forming continents. The Phanerozoic Eon began about 570 million years ago and continues to the present.

570.00 MILLION YEARS AGO - 500.00 MILLION YEARS AGO : Cambrian Period

Cambrian Period

        The seas of the Cambrian Period are teeming with new forms of life. There are abundant animals with hard parts, such as the trilobite. During this period, all of the animal groups evolve rapidly, including the chordates, ancestors to all vertebrates. By the end of the Cambrian Period, rising global sea levels flood most of the continental landmasses.

570.00 MILLION YEARS AGO - 240.00 MILLION YEARS AGO : Paleozoic Era

Paleozoic Era

        The Paleozoic Era begins about 570 million years ago with the first shelled animals.It ends about 240 million years ago with the largest mass extinction in Earth’s history. During this era, the continents of the southern hemisphere remain joined, making up the landmass known as Gondwanaland. Toward the end of the era, the continents of the northern hemisphere join together and merge with Gondwanaland to form a single landmass called Pangaea.

580.00 MILLION YEARS AGO - 543.00 MILLION YEARS AGO : Ediacaran Animals Flourish

Ediacaran Animals Flourish

        A distinctive group of animals live in shallow seas at the end of the Proterozoic Eon. Called Ediacaran fauna, these animals have soft bodies, and are for the most part unlike later life forms. A few are recognizable sponges and anemones.

Model of Kimberella

Fossil cast of Kimberella

Model of Charnia

Fossil cast of Charnia

Model of Tribrachidium

Fossil cast of Tribrachidium

Model of Spriggina

Fossil cast of Spriggina

Model of Panvancorina

Fossil cast of Panvancorina

Model of Dickinsonia

Fossil cast of Dickinsonia

590.00 MILLION YEARS AGO : Meteorite Hits Australia

Meteorite Hits Australia

        A meteorite hits present-day southern Australia, forming the Acraman crater. Acraman is 160 km (99 mi) in diameter.

1.12 BILLION YEARS AGO - 1.10 BILLION YEARS AGO : Keweenawan Flood Basalts Form

Keweenawan Flood Basalts Form

        In North America, large volumes of lava called flood basalts erupt in the Lake Superior basin, building a plateau-like rock formation. Lava also congeals underground, forming what is called intrusive rock. This intrusive rock formation is named the Duluth Complex.

1.18 BILLION YEARS AGO : Diamonds Form in Australia

Diamonds Form in Australia

       One of the richest diamond deposits in the world forms in Argyle, northwestern Australia. These diamonds probably form in an uncommon type of potassium-rich igneous rock called lamproite, and are later carried to the surface by ascending lamproite and kimberlite magmas.

1.50 BILLION YEARS AGO - 900.00 MILLION YEARS AGO : Belt-Purcell Basin Forms

Belt-Purcell Basin Forms

        Various kinds of sedimentary rock, including sandstone, shale, and limestone, accumulate in a shallow marine basin between Laurasia and Siberia.

1.80 BILLION YEARS AGO : Eukaryotes Appear

Eukaryotes Appear

        Eukaryotes, organisms whose cells contain a nucleus, form. They are followed by specialized eukaryotes such as red, brown, and green algae. Eukaryotes likely evolved from primitive prokaryotes, organisms that have no nucleus.

1.85 BILLION YEARS AGO : Meteorite Hits Ontario, Canada

Meteorite Hits Ontario, Canada

        A meteorite hits present-day northern Ontario, Canada. It creates a structure 200 km (124 mi) in diameter called the Sudbury impact basin.

1.97 BILLION YEARS AGO : Meteorite Hits South Africa

Meteorite Hits South Africa

        A meteorite impact in present-day South Africa creates a structure of contorted rocks called the Vredefort Dome. The dome is 140 km (87 mi) in diameter.

Vredefort Dome

2.06 BILLION YEARS AGO : Bushveld Complex Forms

Bushveld Complex Forms

        Molten rock breaks through the earth’s crust and slowly cools to form a large, shallow deposit of rocks and minerals in what will become South Africa. Within the resulting formation, known as the Bushveld complex, lie the world’s richest reserves of platinum.

2.19 BILLION YEARS AGO : Kimberlite Pipes Form

Kimberlite Pipes Form

        In Australia, large portions of molten rock rise explosively to Earth’s surface, forming what is known as a kimberlite pipe. Kimberlite, an igneous rock, carries diamonds with it to the surface.

       

2.50 BILLION YEARS AGO : Oceanic Oxygen

Oceanic Oxygen

        Banded iron formation, an iron-rich sediment, settles on the ocean floor during the Proterozoic Eon, between 2.5 billion and 1.8 billion years ago. It contains iron oxide, which indicates that the oceans contain oxygen at this time, but the atmosphere does not. 

    

2.59 BILLION YEARS AGO : Great Dyke of Zimbabwe Formed

Great Dyke of Zimbabwe Formed

        Molten rock forces its way into existing rock formations located in modern-day central Zimbabwe. The original rock formations will eventually erode, leaving the remaining rock intrusions to form a long series of low hills through central Zimbabwe that will be known as the Great Dyke. 

2.70 BILLION YEARS AGO - 2.70 BILLION YEARS AGO : Stillwater Complex

Stillwater Complex

        A large mass of magma intrudes through the Archean rocks in the southern Beartooth Range of modern-day Montana. The intrusion, called the Stillwater Complex, contains the richest platinum deposit in North America.

3.20 BILLION YEARS AGO : Diamonds Form

Diamonds Form

        The oldest known diamonds form about 3.2 billion years ago. Diamonds form when carbon, possibly from early life-forms, is buried far below the earth’s surface, where it is subjected to high pressure and relatively low temperature. 

3.50 billion years ago - 2.70 billion years ago : Komatiite Indicates High Temperatures

Komatiite Indicates High Temperatures

        Magnesium-rich lava called komatiite erupts on all continents at temperatures exceeding 1600° C (2900° F) during the Archean Eon.

 Komatiite

3.80 billion years ago - 2.50 billion years ago : Archean Eon

Archean Eon

        Continents form and begin to drift during the Archean Eon. Volcanic gases form the early atmosphere and the oceans. Erosion produces clay minerals and sedimentary rocks. Very hot, magnesium-rich lava flows indicate that Earth’s interior is hotter than it is today. Prokaryotes, one-celled organisms and the ancestors of all life-forms, appear. 

3.85 billion years ago : Fewer Objects Impact Earth

Fewer Objects Impact Earth

        Planetesimals, or asteroid-size bodies, bombard Earth and the Moon less frequently by the time the Archean Eon begins. As a result, newly created continents remain stable for longer periods of time.

4.20 billion years ago : Plate Tectonics Forms Early Continents

Plate Tectonics Forms Early Continents

Rocks from Earth’s crust are recycled into the mantle by the movement of tectonic plates, forming continents possibly as early as 4.2 billion years ago. More substantive geological evidence indicates this activity occurred about 3.6 billion years ago.