Editing Earth's outer core (section)

==== Constraints ====
===== Accretion =====
[[File:Earth_formation.jpg|alt=An artist's illustration of what Earth might have looked like early in its formation. In this image, the Earth looks molten, with red gaps of lava separating with jagged and seemingly-cooled plates of material.|thumb|An artist's illustration of what Earth might have looked like early in its formation.]]

The variety of light elements present in Earth's outer core is constrained in part by [[accretion (astrophysics)|Earth's accretion]].<ref name=":4" /> Namely, the light elements contained must have been abundant during Earth's formation, must be able to partition into [[liquid]] iron at low [[pressure]]s, and must not volatilize and escape during Earth's accretionary process.<ref name=":0" /><ref name=":4" />

===== CI chondrites =====
[[CI chondrite|CI chondritic meteorites]] are believed to contain the same planet-forming elements in the same [[ratio|proportions]] as in the early [[Solar System]],<ref name=":0" /> so differences between CI meteorites and [[primitive mantle|BSE]] can provide insights into the light element composition of Earth's outer core.<ref name=":122">{{Cite journal |last1=Zhang |first1=Youjun |last2=Sekine |first2=Toshimori |last3=He |first3=Hongliang |last4=Yu |first4=Yin |last5=Liu |first5=Fusheng |last6=Zhang |first6=Mingjian |date=2014-07-15 |title=Shock compression of Fe-Ni-Si system to 280 GPa: Implications for the composition of the Earth's outer core |journal=Geophysical Research Letters |volume=41 |issue=13 |pages=4554–4559 |doi=10.1002/2014gl060670 |bibcode=2014GeoRL..41.4554Z |s2cid=128528504 |issn=0094-8276|doi-access=free }}</ref><ref name=":0" /> For instance, the depletion of [[silicon]] in Earth's [[primitive mantle]] compared to CI meteorites may indicate that silicon was absorbed into Earth's core; however, a wide range of silicon concentrations in Earth's outer and [[Earth's inner core|inner core]] is still possible.<ref name=":0" /><ref>{{Cite journal |last1=Georg |first1=R. Bastian |last2=Halliday |first2=Alex N. |last3=Schauble |first3=Edwin A. |last4=Reynolds |first4=Ben C. |date=2007 |title=Silicon in the Earth's core |url=https://www.nature.com/articles/nature05927 |journal=Nature |language=en |volume=447 |issue=7148 |pages=1102–1106 |doi=10.1038/nature05927 |pmid=17597757 |bibcode=2007Natur.447.1102G |s2cid=1892924 |issn=1476-4687|url-access=subscription }}</ref><ref>{{Cite journal |last1=Dauphas |first1=Nicolas |last2=Poitrasson |first2=Franck |last3=Burkhardt |first3=Christoph |last4=Kobayashi |first4=Hiroshi |last5=Kurosawa |first5=Kosuke |date=2015-10-01 |title=Planetary and meteoritic Mg/Si and δ30Si variations inherited from solar nebula chemistry |url=https://www.sciencedirect.com/science/article/pii/S0012821X15004355 |journal=Earth and Planetary Science Letters |language=en |volume=427 |pages=236–248 |doi=10.1016/j.epsl.2015.07.008 |arxiv=1507.02922 |bibcode=2015E&PSL.427..236D |s2cid=20744455 |issn=0012-821X}}</ref>