@article{fdi:010071012,
  title = {{V}ertical changes of the {C}o and {M}n speciation along a lateritic regolith developed on peridotites ({N}ew {C}aledonia)},
  author = {{D}ublet, {G}. and {J}uillot, {F}arid and {B}rest, {J}. and {N}oel, {V}. and {F}ritsch, {E}mmanuel and {P}roux, {O}. and {O}livi, {L}. and {P}loquin, {F}. and {M}orin, {G}.},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ecause they can host significant amounts of {C}o, the {M}n-oxides are commonly considered as the major {C}o-bearing mineral species in lateritic environments. {H}owever, little is known about the process leading to the formation and/or the weathering of these {C}o-rich {M}n-oxides. {T}his lack of knowledge is mainly due to the fact that {C}o concentrations are too low in primary silicates for classical speciation analysis. {I}n this study, we investigated both {C}o and {M}n speciation in a 64 m thick lateritic regolith developed upon peridotites in {N}ew {C}aledonia, by combining {H}igh {E}nergy {R}esolution {F}luorescence {D}etection {X}-ray absorption {N}ear {E}dge {S}tructure ({HERFD}-{XANES}) spectroscopy at the {C}o {K}-edge with classical {XANES} spectroscopy at the {M}n {K}-edge, bulk chemistry ({ICP}) and mineralogy ({XRD}). {T}he results obtained provide new insights into the evolution of {C}o and {M}n speciation as a function of the weathering stages. {C}o and {M}n primarily occur as {C}o({II}) and {M}n({II}, {III}) in olivine and serpentine in the bedrock. {D}uring the first weathering stage, these forms of {C}o and {M}n are progressively oxidized toward {C}o({III}) and {M}n({III}, {IV}), which occur mainly as {C}o({III})-bearing {M}n({III}/{IV})-oxides in the transition between the saprolite and the laterite. {I}n the uppermost lateritic horizons, long-time weathering resulted in a strong leaching of {C}o and {M}n, and the remaining of these elements occurs as {C}o({II}) and {M}n({III}) substituting for {F}e({III}) in goethite. {T}his latter scavenging process emphasizes the importance of {F}e-oxides for the long-term stabilization of {C}o and {M}n in such deeply weathered laterites.},
  keywords = {{L}aterite ; {C}obalt ; {M}anganese ; {S}peciation ; {W}eathering ; {X}-ray absorption spectroscopy ; {NOUVELLE} {CALEDONIE}},
  booktitle = {},
  journal = {{G}eochimica et {C}osmochimica {A}cta},
  volume = {217},
  numero = {},
  pages = {1--15},
  ISSN = {0016-7037},
  year = {2017},
  DOI = {10.1016/j.gca.2017.07.010},
  URL = {https://www.documentation.ird.fr/hor/fdi:010071012},
}