Iron compounds of soils formed over limestone in Galicia in relation to soil color
Authors
M.T. Taboada
Universidad de A Coruña
B.M. Silva
Universidad de Santiago de Compostela
M.T. Barral
Universidad de Santiago de Compostela
Keywords:
Suelos sobre calizas, hematites, goethita, color, Galicia, NW España
Abstract
We study the iron compounds of four soils formed over limestone in Galicia (NW. Spain) in relation to soil colour. Selective extraction suggested a clear predominance of crystalline iron over amorphous forms, a finding confirmed by mineralogical examination. Goethite and magnetite were found in the sand fraction of all four soils, and hematite in that of two. Goethite likewise predominated in the clay fraction, in which hematite was found only occasionally, and then only in trace quantities. The redness of the soils is attributed to inherited hematite in the sand fraction, and brown colouring to their goethite.
