TY - JOUR
T1 - How did early earth become our modern world?
AU - Carlson, Richard W.
AU - Garnero, Edward
AU - Harrison, T. Mark
AU - Li, Jie
AU - Manga, Michael
AU - McDonough, William F.
AU - Mukhopadhyay, Sujoy
AU - Romanowicz, Barbara
AU - Rubie, David
AU - Williams, Quentin
AU - Zhong, Shijie
PY - 2014/5
Y1 - 2014/5
N2 - Several features of Earth owe their origin to processes occurring during and shortly following Earth formation. Collisions with planetary embryos caused substantial melting of the growing Earth, leading to prolonged core formation, atmosphere outgassing, and deepening of the magma ocean as Earth grew. Mantle noble gas isotopic compositions and the mantle abundance of elements that partition into the core record this very early Earth differentiation. In contrast, the elements that are not involved in either core or atmosphere formation show surprisingly muted evidence of the fractionation expected during magma ocean crystallization, and even this minimal evidence for early intramantle differentiation appears to have been erased by mantle convection within ∼1.5 billion years of Earth formation. By 4.36 Ga, Earth's surface and shallow interior had reached temperatures similar to those of the present Earth, and mantle melting, and perhaps plate subduction, was producing crustal rock types similar to those seen today. Remnants of early Earth differentiation may still exist in the deep mantle and continue to influence patterns of large-scale mantle convection, sequestration of some trace elements, geomagnetic reversals, vertical motions of continents, and hot-spot volcanism.
AB - Several features of Earth owe their origin to processes occurring during and shortly following Earth formation. Collisions with planetary embryos caused substantial melting of the growing Earth, leading to prolonged core formation, atmosphere outgassing, and deepening of the magma ocean as Earth grew. Mantle noble gas isotopic compositions and the mantle abundance of elements that partition into the core record this very early Earth differentiation. In contrast, the elements that are not involved in either core or atmosphere formation show surprisingly muted evidence of the fractionation expected during magma ocean crystallization, and even this minimal evidence for early intramantle differentiation appears to have been erased by mantle convection within ∼1.5 billion years of Earth formation. By 4.36 Ga, Earth's surface and shallow interior had reached temperatures similar to those of the present Earth, and mantle melting, and perhaps plate subduction, was producing crustal rock types similar to those seen today. Remnants of early Earth differentiation may still exist in the deep mantle and continue to influence patterns of large-scale mantle convection, sequestration of some trace elements, geomagnetic reversals, vertical motions of continents, and hot-spot volcanism.
KW - Accretion
KW - Differentiation
KW - Early Earth
KW - Giant impacts
KW - LLSVP
KW - Magma ocean
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U2 - 10.1146/annurev-earth-060313-055016
DO - 10.1146/annurev-earth-060313-055016
M3 - Review article
AN - SCOPUS:84902184550
SN - 0084-6597
VL - 42
SP - 151
EP - 178
JO - Annual Review of Earth and Planetary Sciences
JF - Annual Review of Earth and Planetary Sciences
ER -