Vermiculite, with hydroxy-aluminium interlayer, and kaolinite formation in a subtropical sandy soil from south Brazil
| Autor: | Miguel Pernes, Daniel Tessier, J. C. Dur, Edson Campanhola Bortoluzzi, Bruce Velde |
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| Přispěvatelé: | Universidade de Passo Fundo, École normale supérieure - Cachan (ENS Cachan), Unité de recherche Science du Sol (USS), Institut National de la Recherche Agronomique (INRA) |
| Rok vydání: | 2008 |
| Předmět: |
PARTICLE SIZE DISTRIBUTION
XRD [SDV]Life Sciences [q-bio] HYDROXY-Al INTERLAYER SANDY SOILS Mineralogy 020101 civil engineering 02 engineering and technology engineering.material Vermiculite 010502 geochemistry & geophysics 01 natural sciences 0201 civil engineering Geochemistry and Petrology Kaolinite SOIL GENESIS Gibbsite 0105 earth and related environmental sciences Acrisol 15. Life on land BRAZIL Pedogenesis [SDE]Environmental Sciences Illite engineering Soil horizon Clay minerals Geology |
| Zdroj: | Clay Minerals Clay Minerals, Mineralogical Society, 2008, 43 (2), pp.185-193(9). ⟨10.1180/claymin.2008.043.2.03⟩ |
| ISSN: | 1471-8030 0009-8558 |
| DOI: | 10.1180/claymin.2008.043.2.03 |
| Popis: | The purpose of this study was to investigate the clay mineral phases in a Rhodic Acrisol soil and to discuss their evolution in subtropical conditions. Prairie and forest soil profiles were sampled and clay fractions of the parent material and soil horizons analysed by X-ray diffraction (XRD) at the Federal University of Santa Maria, Rio Grande do Sul-Brazil. The XRD results show the presence of interstratified kaolinite-smectite and illite-smectite as well as illite in the parent material. These minerals were also found in the soil samples but with two new phases: hydroxy-aluminium interlayered vermiculite (HIV), which showed incomplete collapse with treatment at 550ºC, and a newly formed kaolinite (d= 7.17 Å). Under a subtropical climate and a sandy lithology, HIV and kaolinite appear to be a result of a specific pedogenic clay formation, related to the natural vegetation. Originally, under the prairie area, the intensity of the weathering processes was weak (within 2:1 clay minerals), as only small quantities of kaolinite and Fe oxides, and no evidence of gibbsite, were found. |
| Databáze: | OpenAIRE |
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