STUDY OF THE EVOLUTION OF SUPERGENE ALTERATION PROCESSES OF GRANITIC ROCKS - INDEPENDÊNCIA GRANITE - MORRO DO IPA, PORTO ALEGRE, RS
DOI:
https://doi.org/10.22456/1807-9806.37376Keywords:
supergene alteration, Independência Granite, clay minerals.Abstract
The rocks of the earth's surface are constantly exposed to the action of natural agents such as water, temperature variations, atmospheric gases and the action of living beings. Among the action of living beings, in the urban centers highlight the anthropogenic, which often ends up by degrading natural resources. In this context, understanding the processes of transformation of the rocks, you can understand the genesis and evolution of soils, and improve methods for their recovery. This study was conducted in a profile altered granitic rock located in the urban area of Porto Alegre, where eight samples were collected representing different levels, from rock to soil. The samples were analyzed by X-ray diffraction, by the powder method on whole rock and in the fraction <4 micrometers. The composition was determined by X-ray fluorescence. Fragments of the samples were observed by scanning electron microscopy (secondary electrons). Petrographic and mineralogical studies showed that there is little variation in the mineralogical composition of the vertical profiles, mainly composed of quartz, feldspar, and kaolinite, identified in all horizons, and illite/biotite, identified in saprolitic horizons. Analyzes whit secondary electron images allowed to identify even the presence of halloysite. The exudation of the iron plates of biotite observed in the optical microscope marking the beginning of supergene alteration in granite. X-ray fluorescence data show that the choice of the reference element property to check whether or not the enrichment of elements along the profile is very important since this paper was verified that Aluminum has a movable behavior probably associated with conditions soil acidity.Downloads
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Published
2012-12-31
How to Cite
NEUMANN, M. H., MEXIAS, A. S., VIGNOL-LELARGE, M. L., GOMES, M. E. B., INDA Jr., A. V., CANER, L., … RAMOS, E. F. (2012). STUDY OF THE EVOLUTION OF SUPERGENE ALTERATION PROCESSES OF GRANITIC ROCKS - INDEPENDÊNCIA GRANITE - MORRO DO IPA, PORTO ALEGRE, RS. Pesquisas Em Geociências, 39(3), 213–229. https://doi.org/10.22456/1807-9806.37376
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