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  2. Age of Earth - Wikipedia

    en.wikipedia.org/wiki/Age_of_Earth

    This led him to estimate that Earth was about 75,000 years old. [ 18 ] [ 19 ] Even earlier, in 1687, in his Principia , the mathematician and physicist Isaac Newton was the first to calculate the age of the Earth by experiment, coming to a conclusion of 50,000 years.

  3. History of Earth - Wikipedia

    en.wikipedia.org/wiki/History_of_Earth

    The first eon in Earth's history, the Hadean, begins with Earth's formation and is followed by the Archean eon at 3.8 Ga. [2]: 145 The oldest rocks found on Earth date to about 4.0 Ga, and the oldest detrital zircon crystals in rocks to about 4.4 Ga, [34] [35] [36] soon after the formation of Earth's crust and Earth itself.

  4. Geological history of Earth - Wikipedia

    en.wikipedia.org/wiki/Geological_history_of_Earth

    Earth formed about 4.54 billion years ago by accretion from the solar nebula, a disk-shaped mass of dust and gas left over from the formation of the Sun, which also created the rest of the Solar System. Initially, Earth was molten due to extreme volcanism and frequent collisions with other bodies.

  5. Geologic Calendar - Wikipedia

    en.wikipedia.org/wiki/Geologic_Calendar

    A variation of this analogy instead compresses Earth's 4.6 billion year-old history into a single day: While the Earth still forms at midnight, and the present day is also represented by midnight, the first life on Earth would appear at 4:00 am, dinosaurs would appear at 10:00 pm, the first flowers 10:30 pm, the first primates 11:30 pm, and ...

  6. Geologic time scale - Wikipedia

    en.wikipedia.org/wiki/Geologic_time_scale

    For example, 201.4 ± 0.2 Ma, the lower boundary of the Jurassic Period, is defined as 201,400,000 years old with an uncertainty of 200,000 years. Other SI prefix units commonly used by geologists are Ga (gigaannum, billion years), and ka (kiloannum, thousand years), with the latter often represented in calibrated units ( before present ).

  7. Geology - Wikipedia

    en.wikipedia.org/wiki/Geology

    Solidified lava flow in Hawaii Sedimentary layers in Badlands National Park, South Dakota Metamorphic rock, Nunavut, Canada. Geology (from Ancient Greek γῆ (gê) ' earth ' and λoγία () ' study of, discourse ') [1] [2] is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over ...

  8. Timeline of natural history - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_natural_history

    The earliest Earth crust probably forms similarly out of similar material. On Earth the pluvial period starts, in which the Earth's crust cools enough to let oceans form. c. 4,404 Ma – First known mineral, found at Jack Hills in Western Australia. Detrital zircons show presence of a solid crust and liquid water.

  9. History of geology - Wikipedia

    en.wikipedia.org/wiki/History_of_geology

    With this enhanced desire for data came an increase in observations of the Earth's composition, which in turn led to the discovery of fossils. In 1687, in his Principia, the mathematician and physicist Isaac Newton was the first to calculate the age of Earth by experiment, based on a globe of iron cooling equal to Earth in size, at 50,000 years ...