Mineralogía de suelos de la Comunidad de Madrid (España)

Abstract

The mineralogy of soils of the Comunidad de Madrid suggest relationship between parent material and soils developped from it. Sometimes it is clear the influence of far material for example in the Fluvisols. Trough researches realized in sand, silt and clay fractions it is possible to deduce the weak bioclimatic weathering in temperated climate. The degree of soil development is limitated: Fluvisols, Arenosols, Regosols, Leptosols and Cambisols, as well as old soils formated under different climatic conditions with argic horizon (Bt): Luvisols and Calcisols. In the wet mountains, the weathering is highly, Mica-Illite and Vermiculite are formed and cambic horizon (Bw), the profile development is: ABC. In semiarid zones, south and southeast of Comunidad de Madrid the bioclimatic weathering is weak with soils of profile AC. The light fraction of fine sand define the mineralogy of soils: Quartz, feldespars, biotite and muscovite in: distric, eutric and humic Cambisols; eutric and umbric Leptosols to north zone of Comunidad; and in cambic Arenosols to the southwest. If the parent material are slates its find Chlorites. The assemblage carbonates, quartz and feldespars it is in luvic petric Calcisols as well as calcaric Cambisol to east and south-east. In rendsic Leptosols developed from Cretaceous limestones near of Torrelaguna show the same mineralogical association. The mineralogy of Fluvisols reflect the heterogenity of a alluvium material: quarzt, feldespars, micas, chlorites and carbonates. The gypsum is the main mineral in gypsiric Regosols. The slight heavy fraction of fine sand suggest the source of igneous, metamorphic or sedimentary parent rock. The weathering in temperated climate mark the amount and nature of clay minerals. This fraction is slight and the principal minerals are: Micas-illites, Vermiculites (sometimes) and Kaolinite. The main process of clay mineral formation in this climate is the transformation. The solis developed from sediments and old terra-rossa have variable amount of clay fraction and the major process are the inheritance.