@article{fdi:010035579,
  title = {{E}olian contribution to soils on {M}ount {C}ameroon : isotopic and trace element records},
  author = {{D}ia, {A}. and {C}hauvel, {C}. and {B}ulourde, {M}. and {G}{\'e}rard, {M}artine},
  editor = {},
  language = {{ENG}},
  abstract = {{W}e determined {S}r, {N}d and {P}b isotopic compositions and major- and trace-element compositions of soil samples recovered from three soil profiles developed on relatively young pyroclastic deposits, less than 10,000 years old, of the {M}ount {C}ameroon volcano. {T}he time elapsed since then is short compared with the half-lives of {R}b, {S}m, {U} and {T}h, suggesting that radioactive decay can be neglected. {W}e therefore assumed that (i) these polyphase soils developed on isotopically homogenous substrates and (ii) any isotopic variation within such profiles cannot be due to selective dissolution of primary minerals with isotopic compositions different from that of bulk bedrock. {A}ny {S}r, {N}d or {P}b isotopic variation would therefore record an allochtonous input occurring either in a solid or dissolved state. {S}r and {N}d isotope compositions change systematically with depth in the soil profile; in particular, {S}r-87/{S}r-86 ratios are far greater in the humic horizons than in the underlying horizons, except in the {CA}9{H} soil profile. {A}lthough smaller than for {S}r isotope compositions, {N}d-143/{N}d-144 ratios displayed an inverse relationship with a decrease towards the uppermost organic-rich horizons. {T}hese isotope shifts correlate with changes in {S}r and {N}d contents, suggesting an allochtonous input characterized by significantly different isotope compositions and slightly lower {S}r contents but higher {N}d contents. {P}b isotopic compositions and {P}b concentrations in the uppermost horizons were distinct from those of underlying horizons in the soil sequences. {S}ince an anthropogenic contamination such as from leaded petrol cannot explain the {P}b shifts, a natural source has to be invoked for {P}b, as well as for {S}r and {N}d. {C}onsidering both the wind paths in {W}est {A}frica and the isotopic shifts registered in the uppermost horizons, {S}aharan dust appears to be the best candidate to explain such variations. {T}hese inputs probably happened in winter when dry warm {H}armattan wind blows from the northeast. {A} maximum of 8% of {S}aharan dust accretion was calculated for the {M}ount {C}ameroon soils. {T}his corresponds to average dust deposition rates between 1.3 and 0.8 g cm(-2) ka(-1), values that are much higher than those found in {H}awaiian soils by {K}urtz et al. [{K}urtz, {A}.{C}., {D}erry, {L}.{A}., {C}hadwick, {O}.{A}., 2001. {A}ccretion of {A}sian dust to {H}awaiian soils: {I}sotopic, elemental and mineral mass balances. {G}eochim. {C}osmochim. {A}cta 65, 1971-1983.], and are probably related to shorter distance between dust source and deposit. {A}ny elemental mass balance calculated in the upper organic-rich horizons should be then corrected from allochtonous wind-borne {S}aharan dust before evaluating weathering-linked chemical mobilities. {P}ublished by {E}lsevier {B}.{V}.},
  keywords = {{E}olian dust ; {S}r {N}d {P}b isotopes ; trace elements ; soils ; {M}ount {C}ameroon},
  booktitle = {},
  journal = {{C}hemical {G}eology},
  volume = {226},
  numero = {3-4},
  pages = {232--252},
  ISSN = {0009-2541},
  year = {2006},
  DOI = {10.1016/j.chemgeo.2005.09.022},
  URL = {https://www.documentation.ird.fr/hor/fdi:010035579},
}