@article{fdi:010045564,
  title = {{D}evelopment and origin of the microgranular structure in latosols of the {B}razilian {C}entral {P}lateau : significance of texture, mineralogy and biological activity},
  author = {{R}eatto {B}raga, {A}. and {B}ruand, {A}. and {D}e {S}ouza {M}artins, {E}. and {M}uller, {F}. and {M}edrado da {S}ilva, {E}. and {A}bilio de {C}arvalho, {O}. and {B}rossard, {M}ichel and {R}ichard, {G}.},
  editor = {},
  language = {{ENG}},
  abstract = {{B}razilian {L}atosols are characterized by low activity clay, little horizon differentiation, a weak macrostructure and a strong microgranular structure. {T}he development of the latter that was reported as being possibly related to the. ne material mineralogy, location in the landscape, parental material and biological activity is still under discussion. {T}he aim of this study is to discuss the origin of the microgranular structure of {L}atosols located in the {B}razilian {C}entral {P}lateau. {T}en {L}atosols ({L}) developed in different parent materials were selected along an approximately 350-km long regional toposequence across the {S}outh {A}merican {S}urface ({SAS}) ({L}1 to {L}4) and {V}elhas {S}urface ({VS}) ({L}5 to {L}10). {T}he structure of the {L}atosols was studied in the field and samples of the diagnostic {B}w horizons were collected for laboratory analyses. {B}asic soil characterization was performed on the <2-mm material according to the {B}razilian standard procedures. {T}he {S}i{O}2, {AL}(2){O}(3), {F}e2{O}3 and {T}i{O}2 content was determined after dissolution with 1:1 {H}2{SO}4. {T}he microstructure was studied in optical microscopy and scanning electron microscopy in thin sections. {T}he results showed a varying compound strong microgranular structure and weak to moderate medium sub-angular blocky structure independently of the landscape position as well as the parental material, except for the {L}atosol developed on a quartzite. {T}he {L}atosols were classified as gibbsitic-sesquioxidic, kaolinitic non-sesquioxid, or kaolinitic-sesquioxid {L}atosols but there was no relationship between their composition and the development of the microgranular structure in the {B}w horizon. {T}he analyses showed indeed several types of microgranular structure with different proportions but without any relationship with their texture and mineralogy. {A}ctually, the types of microgranular structure appeared to be mainly related to soil bioturbation by termites and eventually secondarily by ants. {T}hus, the weak macrostructure and strong microgranular structure of the {L}atosols studied, the little vertical differentiation of the horizons, and the lack of a clear relationship between their landscape position and parent material characteristics would result from long-term biotic action with high probability.},
  keywords = {{STRUCTURE} {DU} {SOL} ; {MICROSTRUCTURE} ; {ANALYSE} {MINERALOGIQUE} ; {ANALYSE} {PHYSICOCHIMIQUE} ; {ARGILE} ; {KAOLINITE} ; {GIBBSITE} ; {FAUNE} {DU} {SOL} ; {TERMITE} ; {BRESIL}},
  booktitle = {},
  journal = {{C}atena},
  volume = {76},
  numero = {2},
  pages = {122--134},
  ISSN = {0341-8162},
  year = {2009},
  DOI = {10.1016/j.catena.2008.10.003},
  URL = {https://www.documentation.ird.fr/hor/fdi:010045564},
}