Genesis of textural contrasts in subsurface soil horizons in the Northern Pantanal-Brazil

Revista Brasileira de Ciência do Solo

Alexandre Ferreira Do Nascimento²  Sheila Aparecida Correia Furquim¹  Eduardo Guimarães Couto¹  Raphael Moreira Beirigo¹  Jairo Calderari De Oliveira Júnior¹  Plínio Barbosa De Camargo¹  Pablo Vidal-torrado¹ 

[1] ,Embrapa Solos UEP Recife Recife PE ,Brazil

关键词: alluvial soils;    hydromorphic soils;    fluvial deposition system;    alluvial fans;    avulsion;    solos aluviais;    solos hidromórficos;    sistema deposicional fluvial;    leque aluvial;    avulsão;   

DOI  :  10.1590/S0100-06832013000500001

来源: SciELO

【 摘 要 】

The Pantanal region can be characterized as a quaternary floodplain with predominant sedimentation in the form of alluvial fans. In the geomorphologic and sedimentary evolution, the avulsion process is inherent to this depositional system and its dynamics, together with surface water floods, influence soil sedimentation on this plain. The knowledge and differentiation of these two events can contribute to a better understanding of the variability of soil properties and distribution under the influence of these sedimentation processes. Therefore, this study investigated the genesis of soils in the Northern Pantanal with textural contrasts in deeper horizons and their relationship with the depositional system dynamics. We analyzed four soil profiles in the region of Barão de Melgaço, Mato Grosso State, Brazil (RPPN SESC Pantanal). Two profiles were sampled near the Rio Cuiabá (AP1 and AP4) and two near the Rio São Lourenço (AP10 and AP11). In AP11, the horizons contrast in particle size between the profile basis and the surface. In AP1, AP4 and AP10, the horizons overlaying the sand layer have similar particle size properties, mainly in terms of sand distribution. In the first case, floods (surface water) seem to have originated the horizons and layers with contrasting texture. In the second case, avulsion is the most pronounced process. Therefore, the two modes can form soils with contrasting texture that are discriminable by soil morphology, based on the distinct features associated to the specific sedimentation processes.

【 授权许可】

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