EDAFOLOGÍA

Publicada por la Sociedad Española de la Ciencia del Suelo

 

Volumen 8. Abril 2001. pág 9-19.

 

 

 

VERMICULITA EN SUELOS DESARROLLADOS SOBRE GNEIS

 

I. Hernando Massanet*, J. Hernando Costa*, A. Barba Carretero* y C. Barba Solana**.

* Departamento de Edafología. Facultad de Farmacia. Universidad Complutense de Madrid. Ciudad Universitaria. Plaza Ramón y Cajal s/n. 28040 Madrid.

** Centro de Microscopía Electrónica de la Universidad Complutense de Madrid. 28040 Madrid.

 

Abstract. The chemical composition of vermiculites in parent material and in the clay size fraction of soils are studied by Analytical Transmission Electron Microscopy (T.E.M.). The soils are: dystric, eutric, umbric and mollic Leptosols; eutric and dystric Cambisols; and haplic Phaeozems (FAO, 1998). The parent material is a gland gneis. The gneis vermiculite is dioctahedral with hydroxy aluminium interlayered. The vermiculites of the clay size fraction into the soils horizons are di-trioctahedral and in some cases are the same to vermiculite of the gneis.

In temperate climate and lightly acid enviroments, in Lozoya river Valley (Guadarrama Ridge. Madrid), the di-trioctahedral vermiculite of the soils is formed by biotite weathering or from chlorite by the following sequence: Biotite Chlorite Vermiculite.

Key words: Vermiculite, gneiss, soils, T.E.M.

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