@article{fdi:010077047,
  title = {{L}ateritic weathering of trachyte, and bauxite formation in {W}est {C}ameroon : morphological and geochemical evolution},
  author = {{M}omo, {M}. {N}. and {B}eauvais, {A}nicet and {T}ematio, {P}. and {A}mbrosi, {J}. {P}. and {Y}emefack, {M}. and {Y}erima, {B}. {P}. {K}. and {Y}ongue-{F}ouateu, {R}.},
  editor = {},
  language = {{ENG}},
  abstract = {{B}auxites and {F}e laterites were formed on {N}eogene volcanics from {F}ongo-{T}ongo region in the highlands of western {C}ameroon, and are distributed on plateaus, slopes and downslope surfaces. {B}auxitic profiles result from intense in-situ weathering of trachytes that implied depletion of silica and labile elements from the saprolite, while alumina relatively accumulated from parent minerals pseudomorphosis by primary gibbsite formation. {D}uring ongoing lateritization and bauxite maturation, important leaching and illuviation processes resulted in secondary gibbsite crystallizations. {L}ate incision and dissection of upper bauxitic plateau resulted in degradation and dismantling of bauxitic duricrusts with {F}e-depletion and increasing silica. {C}ompared to trachyte, bauxitic duricrusts are relatively enriched in {N}b, {Z}r, {G}a, {N}i, {C}u, {C}o, {V}, {C}r, {A}s, {P}b, {T}h, {H}f, {U} and {T}a, while {Y}, {S}r, {R}b, {B}a and {Z}n are depleted. {T}race elements contents depend on relative proportions of gibbsite, kaolinite, iron oxides and anatase and their affinity with these minerals across the weathering sequence. {T}he overall {REE} composition and {C}1-{C}hondrite normalized {REE} patterns highlight significant fractionations with enrichment in the upslope profile and labile behavior in other profiles of the sequence. {REE} behavior and {E}u/{C}e anomalies are controlled by intensity of weathering and lateritic processes during the evolution of profiles. {O}ur results document two major bauxitic phases in the {F}ongo-{T}ongo area, i.e., mid-{M}iocene primary in situ bauxitic weathering of trachyte and late {M}iocene secondary bauxitization of previously formed bauxitic profiles that led to alumina enrichment up to 53.50 wt%. {C}ombined together, the morphological distribution and geochemical composition of the studied bauxitic profiles constitute guides for bauxite exploration, and more generally document the dynamics and morphogenetic evolution of lateritic landforms in {W}est {C}ameroon.},
  keywords = {{B}auxite ; {L}ateritic weathering ; {G}ibbsite ; {R}are earth elements ; {N}eogene ; {C}ameroon ; {CAMEROUN}},
  booktitle = {},
  journal = {{J}ournal of {G}eochemical {E}xploration},
  volume = {205},
  numero = {},
  pages = {art. 106324 [19 ]},
  ISSN = {0375-6742},
  year = {2019},
  DOI = {10.1016/j.gexplo.2019.06.006},
  URL = {https://www.documentation.ird.fr/hor/fdi:010077047},
}