@article{fdi:010042071,
  title = {{G}eoelectrical imaging of a thick regolith developed on ultramafic rocks : groundwater influence},
  author = {{R}obineau, {B}. and {J}oin, {J}.{L}. and {B}eauvais, {A}nicet and {P}arisot, {J}ean-{C}laude and {S}avin, {C}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A} thick regolith with supergene nickel ore deposits, developed from ultramafic rocks in {N}ew {C}aledonia (southwest {P}acific), was investigated using electrical resistivity tomography ({ERT}), {T}his paper presents the results of an electrical survey and monitoring of the lateritic weathering mantle of {T}iebaghi plateau. {R}esistivity pseudosections, validated by many borehole logs, contributed to defining a four-layer geoelectric model corresponding to four main weathering horizons: (1) ferricrete with soft nodular horizon; (ii) red mottled zone and yellow fine saprolite; (iii) coarse saprolite; and (iv) bedrock. {A}ll geoelectric sections reveal undulated bedrock topography, with each high representing a resistive bedrock ridge and each swale corresponding to a conductive saprolite trough. {W}hen parallel pseudosections are correlated, most ridges and troughs hove a prominent northeast-southwest strike. {S}easonal monitoring of a selected {ERT} profile shows that the geoelectric structure is well preserved through time. {L}ocal resistivity variations occur in the mottled zone-fine saprolite layer and along a major fracture zone, and are interpreted as being due to water content variations in groundwater pathways. {O}n the basis of field and laboratory experiments, it is proposed that the resistivity variations are not due to dewatering but could result from fluctuations in groundwater chemistry. {ERT} appears to be a useful tool to document the geometry of the regolith and the groundwater flow pattern in weathering horizons and bedrock.},
  keywords = {electrical resistivity tomography ; groundwater ; laterite ; {N}ew {C}aledonia ; regolith ; saprolite ; ultramafic rocks},
  booktitle = {},
  journal = {{A}ustralian {J}ournal of {E}arth {S}ciences},
  volume = {54},
  numero = {5},
  pages = {773--781},
  ISSN = {0812-0099},
  year = {2007},
  DOI = {10.1080/08120090701305277},
  URL = {https://www.documentation.ird.fr/hor/fdi:010042071},
}