@article{fdi:010066612,
  title = {{C}an mima-like mounds be {V}ertisol relics ({F}ar {N}orth {R}egion of {C}ameroon, {C}had {B}asin) ?},
  author = {{D}iaz, {N}. and {D}ietrich, {F}. and {C}ailleau, {G}. and {S}ebag, {D}avid and {N}gounou {N}gatcha, {B}. and {V}errecchia, {E}.{P}.},
  editor = {},
  language = {{ENG}},
  abstract = {{N}on-anthropogenic earth mounds, defined as mima-like mounds in this study, have recently been observed in non-carbonate watersheds along the {S}udano-{S}ahelian belt in the {C}had {B}asin. {I}n the {D}iamare piedmont (northern {C}ameroon) they are particularly well developed within stream networks. {I}n less eroded areas, they occur as whaleback, flattened morphologies, or even as buried features. {A}ll these shapes are composed of clay-rich sediment associated with high proportions of secondary carbonate nodules and {F}esingle bond{M}n micro-nodules. {T}heir soil structure is prismatic to massive and vertical cracks are observed locally. {G}rain-size distributions emphasize the clay-rich nature of the sediment, with average clay contents of 32% ± 12.8% (n = 186), which is significantly higher than the clay content in the adjacent sediments in the landscape (mean = 10% ± 4%, n = 21). {M}oreover, high proportions of smectite characterize the soil, with average contents of 34 ± 7% (n = 25). {A}t the micro-scale, the groundmass has a cross-striated b-fabric, with embedded smooth subangular quartz and feldspar grains of the silt-size fraction. {A}ll the characteristics point to altered vertic properties in the clay-rich sediment composing the mima-like mounds. {M}ima-like mounds are thus interpreted as degraded {V}ertisols. {C}ompared to present-day {V}ertisols occurring in the piedmont, mima-like mounds are located upstream. {I}t is thus proposed that the {V}ertisol areas were more extensive during a former and wetter period than the present-day. {S}ubsequent changing climatic conditions increased erosion, revealing the gilgai micro-relief by preferential erosion in micro-lows rather than in micro-highs. {M}ima-like mounds of the {C}had {B}asin might thus result from pedogenesis combined with later erosion. {T}hese local processes can be inherited from regional climatic variations during the {L}ate {P}leistocene-{H}olocene and likely be related to the {A}frican {H}umid {P}eriod.},
  keywords = {{CAMEROUN} ; {ZONE} {SOUDANOSAHELIENNE} ; {TCHAD} {BASSIN}},
  booktitle = {},
  journal = {{G}eomorphology},
  volume = {261},
  numero = {},
  pages = {41--56},
  year = {2016},
  DOI = {10.1016/j.geomorph.2016.02.021},
  URL = {https://www.documentation.ird.fr/hor/fdi:010066612},
}