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Genetic relationships between ferralsols, podzols and white kaolin in A mazonia
Author(s) -
Ishida D. A.,
Montes C. R.,
Lucas Y.,
Pereira O. J. R.,
Merdy P.,
Melfi A. J.
Publication year - 2014
Publication title -
european journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 1351-0754
DOI - 10.1111/ejss.12167
Subject(s) - podzol , kaolinite , dissolution , groundwater , chemistry , leaching (pedology) , geology , mineralogy , soil science , geochemistry , soil water , environmental chemistry , geotechnical engineering
Summary White kaolin has frequently been observed to be associated with ferralsol‐podzol soil systems in A mazonia. In order to evaluate whether such systems favour kaolin genesis and to identify the associated genetic processes, we studied soil organization, mineralogy and groundwater properties of a ferralsol‐podzol soil system with white kaolin located in the H igh R io N egro B asin, B razil. We found that the kaolin was situated near the ferralsol‐podzol transition and that its thickness was related to the depth of landscape incision by regressive erosion. The kaolin was characterized by silicon, iron and titanium ( Ti ) leaching and aluminium ( Al ) absolute accumulation. The groundwater that percolates from the podzol to the kaolin can enhance kaolinite precipitation, by supplying Al originating from kaolinite dissolution in the overlying Bh , and kaolin bleaching, by low pH and Eh of the percolating waters favouring iron reduction. The system dynamics imply that the quartz dissolution rate in the kaolin is of at least the same order of magnitude as the kaolinite dissolution rate in the overlying Bh . Within the whole system, Ti appeared to be very mobile.