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Earth formed around 4.54 billion years ago, approximately one-third the age of the universe, by accretion from the solar nebula. [4][5][6] Volcanic outgassing probably created the primordial atmosphere and then the ocean, but the early atmosphere contained almost no oxygen.
The main topics studied in Earth history are paleogeography, paleontology, and paleoecology and paleoclimatology—respectively, past landscapes, past organisms, past ecosystems, and past environments. This chapter will cover (briefly) the origin of the universe and the 4.6 billion year history of Earth.
Geologic time, the extensive interval of time occupied by the geologic history of Earth. Formal geologic time begins with the Archean Eon (4.0 billion to 2.5 billion years ago) and continues to the present day.
About 1,000,000,000 years ago, Earth had its first signs of life. Single-celled organisms consumed the sun’s energy. As a waste product, these cyanobacteria eventually filled the oceans and atmosphere with oxygen. Next, an oxygenated atmosphere paved the way for more complex life forms to exist.
The solid Earth as a field of study is covered in geologic sciences, the methods and instruments employed to investigate Earth’s surface and interior are discussed in Earth exploration, and the history of the study of Earth from antiquity to modern times is surveyed in Earth sciences.
The geological history of the Earth follows the major geological events in Earth's past based on the geological time scale, a system of chronological measurement based on the study of the planet's rock layers (stratigraphy).
geologic history of Earth, evolution of the continents, oceans, atmosphere, and biosphere. The layers of rock at Earth’s surface contain evidence of the evolutionary processes undergone by these components of the terrestrial environment during the times at which each layer was formed.
252 million years ago, a devastating mass extinction wiped out about 90% of all species on Earth. Follow scientists as they piece together evidence to discover how life survived and set the...
The history of the Earth describes the most important events and stages in the development of the planet Earth from its formation to the present day. The age of the Earth is about 4.56 billion years. [3] . Nearly all branches of science have helped us understand the main events of the Earth's past.
A history-of-Earth timeline includes everything from the birth of the sun and solar system to present-day earthquakes in California. Changes over the past 4.6 billion years were usually slow and incremental, but also sometimes violent and unforeseen, like giant meteorite strikes.