Mineralogical Characterization of 2:1 Clays in Soils: Importance of the Clay Texture
Daniel Tessier, Georges Pédro, 1985. "Mineralogical Characterization of 2:1 Clays in Soils: Importance of the Clay Texture", Proceedings of the International Clay Conference Denver, 1985, Leonard G. Schultz, H. van Olphen, Frederick A. Mumpton
Download citation file:
A correlation was found between the net layer charge and the percentage of nonexchangeable potassium in 2:1 clay minerals having negative charges per half unit cell >0.45. This charge also marks the limit between low-charge smectites having entirely exchangeable cations and other 2:1 clay minerals. Furthermore, on samples prepared at 0.032 bar suction pressure, water retention decreased as the layer charge increased. Transmission electron micrographs, carried out so as to preserve the microstructure of the clay, also showed a relationship between layer charge, stability, and texture. For low-charge smectites (<0.45/half unit cell) exchanged with Na, clay particles were mainly individual crystals. Ca-exchanged clay particles, however, were arranged face-to-face in the form of “quasi-crystals.” High-charge illites (layer charge = 0.8/half unit cell) occurred as stable aggregates that appeared to be characteristic of these minerals. An intermediate behavior was noted for smectites having charges between 0.45 and 0.6/half unit cell.
Figures & Tables
Proceedings of the International Clay Conference Denver, 1985
The papers included in this proceedings volume are representative of the research on clays being conducted in all parts of the world at the time of publication. Many of the subjects treated are controversial, and although some ideas expressed may not necessarily represent the views of the editors, the referees, or the publisher, they deserve to be brought to the attention of the international clay community.