Interelation between depth of soil and geological substrate in the East Center of Minas Gerais State, Brazil

The study of interrelation between soil depth and geological substrate of a place is important to understand the soil genesis and the physical, chemical and morphological attributes of the soil. This is an important tool to evaluate the influence of the parent material characteristics in the weathering and its influence in the depth of a soil profile. The geological data of different rocks were gathered for a studied site. The rock type, its essential minerals, texture and color of the rocks were obtained in the municipalities of Cocais, Rio Doce, Sabinópolis, Virginópolis and Santa Bárbara in the eastern part of the state of Minas Gerais. The soil classes and their parent material data were also examined. Emphasis was given the depth of appearance of the top of the C or B/C horizons for each soil class found in the study sites. The information was obtained by using the data from the geographical information system associated to a simple statistical analysis which relates lithotypes to soil depth. It was possible to group the average data for each soil class and its parent material. It was performed a cluster analysis based on the method of minimum variance. It was used the Euclidian average distance. The results indicated that foliated rocks in relation to a non foliated are related deeper soils, the same way, rocks with coarse grained could accelerate the weathering and form deeper soils than the fine grained rocks.

Soil-geology relation; pedogenesis; weathering

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