Do concentrations of Mn, Eu and Ce in apatite reliably record oxygen fugacity in magmas?

Unique trace element geochemistry of pyrometamorphic apatite-supergroup minerals: a case study of fluorellestadite from burnt coal (Poland) and shale (France) post-mining waste heaps, with emphasis on boron, germanium, aluminium and titanium

“…Although the ap a tite-type struc ture pre fers the Ce 3+ ion due to its larger ionic-size sim i lar ity to Ca 2+ (e.g., Terra et al, 2008), the Ce 4+ -Ca 2+ ionic ra dii dif fer ence is 11%, thus be ing be low the diadochy thresh old of Goldschmidt. Small pos i tive Ce anom alies in apatites, al though not nec es sar ily ex plained, are known (e.g., Bromiley, 2020).…”

Compositional Variations in Apatite and Petrogenetic Significance: Examples from Peraluminous Granites and Related Pegmatites and Hydrothermal Veins from the Central Iberian Zone (Spain and Portugal)

“…Apatite can accommodate a number of elements with a wide range of sizes and valence states owing to its structural tolerance and chemical substitution (e.g., [9] and references therein; [10,12,14,15]). Manganese and, to a minor extent, Fe are the main elements that enter into the apatite structure.…”

“…The higher the polymerization of the melt, the lower the availability of free oxygen and the lower the solubility of Mn in the melt, becoming more compatible in the apatite [20,111]. Other factors that could control Mn partition are the pressure, temperature, volatile content in melts, precipitation of mineral phases competing for Mn and melt composition [6,15].…”

“…Apatite composition may change to a great extent depending on the physicochemical conditions, as its structure allows for different cationic substitutions. Calcium may be mainly replaced by Mn and Fe and, to a minor extent, by REEs Y, Sr, U, Th and Pb, whereas P may be replaced by Si, S and/or As (e.g., [8], and references therein [7,[9][10][11][12][13][14][15]). These replacements in the apatite structure depend upon various factors, such as the host rock nature and melt structure, peraluminosity, fO 2 and temperature, among others (e.g., [4,7,8,10,11,[15][16][17][18][19][20][21]).…”

“…Calcium may be mainly replaced by Mn and Fe and, to a minor extent, by REEs Y, Sr, U, Th and Pb, whereas P may be replaced by Si, S and/or As (e.g., [8], and references therein [7,[9][10][11][12][13][14][15]). These replacements in the apatite structure depend upon various factors, such as the host rock nature and melt structure, peraluminosity, fO 2 and temperature, among others (e.g., [4,7,8,10,11,[15][16][17][18][19][20][21]). Therefore, a detailed study of the chemical composition of apatite in igneous environments may give valuable information on the crystallization conditions of its host rocks.…”