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The geological time scale (GTS), as defined by international convention, [3] depicts the large spans of time from the beginning of the Earth to the present, and its divisions chronicle some definitive events of Earth history. Earth formed around 4.54 billion years ago, approximately one-third the age of the universe, by accretion from the solar ...
Geological history of oxygen. Before photosynthesis evolved, Earth's atmosphere had no free diatomic oxygen (O 2). [2] Small quantities of oxygen were released by geological [3] and biological processes, but did not build up in the atmosphere due to reactions with reducing minerals. Oxygen began building up in the atmosphere at approximately 1. ...
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). Earth formed about 4.54 billion years ago by accretion from the solar nebula, a disk-shaped mass of dust and gas left ...
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The timeline of the early universe outlines the formation and subsequent evolution of the Universe from the Big Bang (13.799 ± 0.021 billion years ago) [1] to the present day. An epoch is a moment in time from which nature or situations change to such a degree that it marks the beginning of a new era or age. Times on this list are measured ...
Creation of the Earth. Wenceslaus Hollar (1607–1677) Dating creation is the attempt to provide an estimate of the age of Earth or the age of the universe as understood through the creation myths of various religious traditions. Various traditional beliefs hold that the Earth, or the entire universe, was brought into being in a grand creation ...
Prehistoric Egypt and Predynastic Egypt was the period of time starting at the first human settlement and ending at the First Dynasty of Egypt around 3100 BC.. At the end of prehistory, "Predynastic Egypt" is traditionally defined as the period from the final part of the Neolithic period beginning c. 6200 BC to the end of the Naqada III period c. 3000 BC.
where κ is the thermal diffusivity of the mantle lithosphere (c. 8 × 10 −7 m 2 /s), a eff is the effective thermal expansion coefficient for rock (c. 5.7 × 10 −5 °C −1), T 1 is the temperature of ascending magma compared to the temperature at the upper boundary (c. 1220 °C for the Atlantic and Indian Oceans, c. 1120 °C for the ...