Premium
Relations entre les distributions granulométriques par granulométrie laser et par analyse d'images en microscopie électronique à transmission de la fraction argileuse d'un sol
Author(s) -
Dur J. C.,
Elsass F.,
Chaplain V.,
Tessier D.
Publication year - 2004
Publication title -
european journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 1351-0754
DOI - 10.1111/j.1365-2389.2004.00597.x
Subject(s) - granulometry , illite , silt , particle size distribution , mineralogy , clay minerals , particle (ecology) , transmission electron microscopy , particle size , volume fraction , kaolinite , chemistry , analytical chemistry (journal) , materials science , geology , composite material , chromatography , nanotechnology , sediment , paleontology , oceanography
Summary The aim of this study was to validate the use of laser granulometry in studies concerning fractions < 2 µm in soils. The study was carried out on the clay fraction of a loamy soil from northeast Thailand. Granulometry by light scattering requires the determination of the refractive indexes of the solid phases. Once these values have been established, laser granulometry can provide a detailed description of the particle‐size distribution within the clay fractions. Laser granulometry showed a multimodal distribution in the clay fraction of this soil. The analysis of images obtained by transmission electron microscopy provided numerical distributions of soil particles, from which representations by surface area and by volume obtained by laser granulometry and by transmission electron microscopy could be compared. The representation of particle‐size distribution by surface area, assuming that particles are similar to circles, is adequate and, in this range of particle size, minimizes the effect of larger diameters. The representation of the particle‐size distribution assuming that particles are similar to platy discs is better than the current representation that assumes particles are similar to spheres. We used transmission electron microscopy to validate laser granulometry in the fractions < 2 µm. Elemental microanalysis was used to identify the mineralogy of the clay particles: illite, illite‐smectite and kaolinite at a magnification of 31 000, corresponding to the clay fraction < 0.8 µm of the particle‐size distribution. Quartz and illite were identified at a magnification of 3300, corresponding to the fraction between 0.8 and 2 µm. The mineral constituents of the soil are correlated with the modes of the particle‐size distribution.