@article{fdi:010071406,
  title = {{I}mpact of incipient weathering on uranium migration in granitic waste rock piles from former {U} mines ({L}imousin, {F}rance)},
  author = {{K}anzari, {A}. and {G}{\'e}rard, {M}artine and {B}oekhout, {F}. and {G}aloisy, {L}. and {C}alas, {G}. and {D}escostes, {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}his study investigates the impact of incipient weathering on uranium ({U}) migration at the surface of granitic waste rock piles from former {U} mines in {L}imousin ({F}rance) operated half a century ago. {W}e used a multi-scale mineralogical and geochemical approach to evaluate the impact of incipient weathering on uranium mobility in a chaotic waste rock pile. {T}he surficial part of five former mines located in the "{L}a {C}rouzille" and "{L}a {C}reuse" mining districts was investigated. {F}our groups of samples were defined based on field observations and mineralogy, granites, lamprophyres, hydrothermally altered rocks and weathering products. {P}etrology, mineralogy and geochemistry investigations show the importance of mineralogical and geochemical transformations during incipient weathering over a few decades. {T}he {C}hemical {I}ndex of {A}lteration ({CIA}) is successfully used to assess the weathering state of samples in the waste rock pile chaotic deposit. {T}he mean {CIA} value is around 60 for unweathered/ incipiently weathered granites whereas highly weathered samples have {CIA} around 70. {T}his means that no significant major element loss occurs in the granitic rocks suffering incipient weathering. {V}arious micron-size secondary {U} minerals consist in a large diversity of oxidized uranyl minerals (uranophane, uranyl sulfate, curite, autunite and other uranyl phosphates), with dominant uranyl phosphates, indicating local {U} mobility in the waste rock pile. {A}utunites micromorphology indicates different degrees of weathering of the samples in which it crystallizes. {U} is primarily concentrated in the clay fraction (< 2 mu m), associated with secondary minerals from granite alteration (clay minerals such as smectite and vermiculite, {F}e-oxides and phosphate minerals) and, to a limited extent, relict primary minerals. {T}hese weathering products contribute to {U} ({VI}) stabilization under oxidizing conditions.},
  keywords = {{FRANCE}},
  booktitle = {},
  journal = {{J}ournal of {G}eochemical {E}xploration},
  volume = {183},
  numero = {{A}},
  pages = {114--126},
  ISSN = {0375-6742},
  year = {2017},
  DOI = {10.1016/j.gexplo.2017.08.010},
  URL = {https://www.documentation.ird.fr/hor/fdi:010071406},
}