| Title | X-ray diffraction and infrared characterization of oxisols from central and southeastern Brazil |
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| Author | Nitzsche, R P; Percival, J B ; Torrance, J K; Stirling, J A R; Bowen, J T |
| Source | Clay Minerals vol. 43, no. 4, 2008 p. 549-560, https://doi.org/10.1180/claymin.2008.043.4.03 |
| Year | 2008 |
| Alt Series | Earth Sciences Sector, Contribution Series 20080634 |
| Publisher | Mineralogical Society |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Area | Minas Gerais; Goiás; Sãn Paulo; Brazil |
| Lat/Long WENS | -49.2500 -43.0000 -18.4167 -23.0000 |
| Subjects | geochemistry; x-ray diffraction; x-ray diffraction analyses; magnetite; goethite; hematite; maghemite; infrared spectral analyses |
| Illustrations | geochemical analyses |
| Released | 2018 07 09 |
| Abstract | Eleven Oxisols with high clay contents, 2.6-59.7 wt.% Fe2O3, and containing hematite, goethite, magnetite and maghemite, from São Paulo, Minas Gerais and Goia´s, Brazil, were studied for the purpose of
microwave remote sensing applications in the 0.3 to 300 GHz range. Of special interest are: the pseudosand effect caused by Fe oxide cementation of clusters of soil particles; the mineralogy; and whether the soil magnetic susceptibility affected by
ferromagnetic magnetite and maghemite interferes with microwave propagation. Quantitative mineralogical analyses were conducted using X-ray diffraction with Rietveld refinement. Visible, near infrared and
short wave infrared spectroscopic analyses
were used to characterize the samples qualitatively for comparison with published spectral radiometry results. Quartz (3-88%), hematite (2-36%) and gibbsite (1-40%) occurred in all soils, whereas kaolinite (2-70%) and anatase (2-13%) occurred in nine
samples. Ilmenite (1-8%) was found in eight soils and goethite (2-39%) in seven. Of the ferromagnetic minerals, maghemite occurred in seven soils (1-13%) and three contained magnetite (<2%). These results will be applied to the interpretation of the
effect of Fe oxides, particularly the ferromagnetic oxides, on microwave interaction with high-Fe soils, with ultimate application to the monitoring of soil water content by microwave remote sensing. |
| GEOSCAN ID | 226342 |
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