Knowra Geological history of Earth Geological history of Earth The reconstructed record of Earth’s formation and development, from its early accretion to the present, based on rocks, fossils, and other geological evidence.
Geologic time scale : A chronological framework dividing Earth’s history into eons, eras, periods, epochs, and ages. Its divisions organize the events and evidence in Earth’s history.
Accretion (astrophysics) : The growth of a celestial body through collisions and gravitational capture of smaller bodies. Collisions among early Solar System bodies assembled the young Earth.
Hadean : The earliest eon of Earth’s history, beginning with its formation about 4.54 billion years ago. It covers Earth’s formation and the earliest surviving traces of its development.
Origin of water on Earth : The scientific problem of determining how Earth acquired and retained its water. The sources and timing of Earth’s oceans remain debated.
Evolution : The change in heritable characteristics of populations across generations. The fossil record documents evolutionary change across deep time.
Geochronology : The science of determining the ages of rocks, fossils, and geological events. Dating methods assign ages to events in the geological record.
Planetary differentiation : The separation of a planet’s materials into layers according to density and chemical behavior. It produced Earth’s core, mantle, and crust from an initially mixed body.
Great Oxidation Event : A major rise in atmospheric oxygen around 2.4 billion years ago, caused chiefly by biological activity. It marks a profound change in atmosphere, oceans, and the conditions for life.
Origin of life : The transition from nonliving chemistry to the first living systems on Earth. The earliest life is difficult to identify in rocks altered over billions of years.
Mass extinction : A geologically brief interval in which a large share of Earth’s species become extinct worldwide. Repeated extinction crises divide the history of life into major transitions.
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