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- Cerium_anomaly abstract "The Cerium anomaly, in geochemistry, is the phenomenon whereby Cerium (Ce) concentration is either depleted or enriched in a rock relative to the other rare earth elements (REEs). A Ce anomaly is said to be \"negative\" if Ce is depleted relative to the other REEs and is said to be \"positive\" if Ce is enriched relative to the other REEs. Cerium is a rare earth element (lanthanide) characterized by two different redox states: III and IV. Contrary to other lanthanide elements which are only trivalent (with the notable exception of Eu2+), Ce3+ can be oxidized by atmospheric oxygen (O2) to Ce4+ under alkaline conditions. The cerium anomaly relates to the decrease in solubility which accompanies the oxidation of Ce(III) to Ce(IV). Under reducing conditions, Ce3+ is relatively soluble while under oxidizing conditions CeO2 precipitates. Sediments deposited under oxic or anoxic conditions can preserve on the long term the geochemical signature of Ce3+ or Ce4+ upon reserve that no early diagenetic transformation altered it. Cerium can occur in nature as a 3+ or 4+ ion, and is a compatible element (at 4+ valency) in zircon and less commonly in silica. Thomas et al., (2003) state that “terrestrial zircons commonly show a positive Ce anomaly due to the incorporation of Ce4+ into zircon, which is because Ce4+ has the same charge and a similar ionic radius than Zr4+ (Ce4+ = 0.97 Å; Zr4+ = 0.84 Å)”. As such, Ce4+ is incorporated into zircon much easier than the larger Ce3+ (ionic radius = 1.143 Å). This shows that both Ce3+ and Ce4+ are present and that the Ce4+ being compatible in zircon is causing the anomaly.".
- Cerium_anomaly wikiPageExternalLink 62a-3-1387.pdf.
- Cerium_anomaly wikiPageID "22629902".
- Cerium_anomaly wikiPageLength "2447".
- Cerium_anomaly wikiPageOutDegree "13".
- Cerium_anomaly wikiPageRevisionID "551805222".
- Cerium_anomaly wikiPageWikiLink Category:Geochemistry.
- Cerium_anomaly wikiPageWikiLink Category:Lanthanides.
- Cerium_anomaly wikiPageWikiLink Cerium.
- Cerium_anomaly wikiPageWikiLink Europium.
- Cerium_anomaly wikiPageWikiLink Europium_anomaly.
- Cerium_anomaly wikiPageWikiLink Geochemistry.
- Cerium_anomaly wikiPageWikiLink Lanthanide.
- Cerium_anomaly wikiPageWikiLink Rare_earth_element.
- Cerium_anomaly wikiPageWikiLinkText "4+".
- Cerium_anomaly wikiPageWikiLinkText "Cerium anomaly".
- Cerium_anomaly wikiPageWikiLinkText "cerium anomaly".
- Cerium_anomaly wikiPageUsesTemplate Template:Chemistry-stub.
- Cerium_anomaly wikiPageUsesTemplate Template:Geology-stub.
- Cerium_anomaly subject Category:Geochemistry.
- Cerium_anomaly subject Category:Lanthanides.
- Cerium_anomaly hypernym Phenomenon.
- Cerium_anomaly type Disease.
- Cerium_anomaly type Group.
- Cerium_anomaly type Group.
- Cerium_anomaly type Lanthanide.
- Cerium_anomaly type Subfield.
- Cerium_anomaly comment "The Cerium anomaly, in geochemistry, is the phenomenon whereby Cerium (Ce) concentration is either depleted or enriched in a rock relative to the other rare earth elements (REEs). A Ce anomaly is said to be \"negative\" if Ce is depleted relative to the other REEs and is said to be \"positive\" if Ce is enriched relative to the other REEs. Cerium is a rare earth element (lanthanide) characterized by two different redox states: III and IV.".
- Cerium_anomaly label "Cerium anomaly".
- Cerium_anomaly sameAs Q5064495.
- Cerium_anomaly sameAs m.05z_204.
- Cerium_anomaly sameAs Q5064495.
- Cerium_anomaly wasDerivedFrom Cerium_anomaly?oldid=551805222.
- Cerium_anomaly isPrimaryTopicOf Cerium_anomaly.