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The first eon in Earth's history, the Hadean, begins with the 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 the Earth's crust and the Earth itself.
How the Earth Was Made is a documentary television series produced by Pioneer Productions for the History Channel.It began as a two-hour special exploring the geological history of Earth, airing on December 16, 2007.
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.
Earth's atmosphere and oceans were formed by volcanic activity and outgassing. [43] Water vapor from these sources condensed into the oceans, augmented by water and ice from asteroids, protoplanets, and comets. [44] Sufficient water to fill the oceans may have been on Earth since it formed. [45]
Due to the strength of Christian beliefs during the 17th century, the theory of the origin of the Earth that was most widely accepted was A New Theory of the Earth published in 1696, by William Whiston. [9] Whiston used Christian reasoning to "prove" that the Great Flood had occurred and that the flood had formed the rock strata of the Earth.
They theorized that the Earth was formed by the solidification of gaseous matter and that the Earth's crust is composed of hard rocks (sila), clay (bhumih) and sand (asma). [20] Theories were also propounded to explain earthquakes (bhukamp) and it was assumed that earth, air and water combined to cause earthquakes. [20]
In geochemistry, the primitive mantle (also known as the bulk silicate Earth) is the chemical composition of the Earth's mantle during the developmental stage between core-mantle differentiation and the formation of early continental crust. The chemical composition of the primitive mantle contains characteristics of both the crust and the ...
1. "Down to Earth" – Beginning by comparing surface conditions on the planets Venus and Mars with the living landscapes of the Earth to highlight how unique the Earth is, the episode describes the goal of the study of geology and introduces major topics the series addresses, including the Earth's heat engines, plate tectonics, volcanism, earthquakes and seismology, erosion, and natural ...