Relationship between Mineralogy and Elemental Composition in Strongly Developed Soils using Principal Components Analysis

8 pages, figures, and tables statistics.The distribution rate of major, minor and trace elements in different size fractions of highly developed soils of central Spain was determined and related to the mineralogy of the soils. Analysis of variance, factor analysis and contingency tables were used. The principal trace element carriers were the 2:1 phyllosilicates and the Fe and Mn-oxides; kaolinite did not play a role in this regard.Peer reviewe

Paragonite in Spanish "raña" soils

11 pages, figures, and tables statistics.This study reports the presence of paragonite in the fine fraction of soils developed from Pliocene-quartenary aged formations (raña) in central Spain and investigates the factors that determine is presence. Paragonite was found in two of the four areas studies. These two areas had a lesse degree of alteration, although of the two, the more altered area had a higher proportion of paragonite. No significant correlation was found hetween paragonite and illite content, although the areas which contain paragonite generally had a higher illite content. The presence of paragonite was determined by the origin of the materials in each of the zones.Peer reviewe

Relación entre la mineralogía y el tamaño de partícula en suelos sobre formaciones pliocuaternarias en el area de Membrillera (Guadalajara)

5 páginas, ilustraciones y tablas estadísticasSe estudia en este trabajo utilizando la técnica de difracción de rayos X...Peer reviewe

High-Charge Smectite in Spanish "Raña" Soils

7 pages, figures, and tables statistics.In a study of "raña" soils of central Spain, hydroxy-interlayered 2:1 clay minerals were identified in the upper horizons and high-charge smectite in the lower horizons, with kaolinite the most abundant phylosilicate. The high-charge smectite showed a basal spacing of 18 Á on Mg-satnration and glycerol solvation and 10 Á on K-saturation and air-drying. It is concentrated in the coarse fractions and appears to be basically a berdellite in the fine-silt fractions and a montmonllonite in the clay fractions. Pre-existing illite was probably transformed into hydroxy-interlayered 2:1 clays in the surface honzons, whercas high-charge smectite formed in the deper horizons. These minerals, which were apparently not stable in the existing soil conditions, were the first stage in the degradation process of illite. The stable mineral in these soil profiles was kaolinite.Peer reviewe

Presencia de paragonita en suelos de Robledo de Corpes (Guadalajara).

[ES] Se estudia la composición mineralógica de distintas fracciones de tres perfiles desarrollados sobre formaciones de raña en Robledo de Corpes. Los minerales predominantes son filosilicatos, cuarzo, goetita, colinita e ilita.[EN] The mineralogical composition of different size-fractions of three profiles developed upon raña formations, in Robledo de Corpes, Guadalajara (Spain), is studied in this paper.Peer reviewe