TRANSMISSION XRAY DIFFRACTION OF （应用x光衍射的传播）.pdf

Clays and Clay Minerals, Vol. 47, No. 5, 637-646, 1999, T R A N S M I S S I O N X - R A Y D I F F R A C T I O N OF U N D I S T U R B E D SOIL MICROFABRICS O B T A I N E D B Y M I C R O D R I L L I N G IN THIN SECTIONS L. DENAIX, 1 E VAN tORT, 2 M. PERNES,2 AND A.G. JONGMANS3 i Unit6 dAgronomie INRA, Domaine de la Grande Ferrade, BP 81, 33883 Villenave dOrnon Cedex, France 2Unit6 de Science du Sol, INRA, Route de St.-Cyr, 78026 Versailles Cedex, France 3Department of Soil Science and Geology, Agricultural University, RO. Box 37, 6700 AA Wageningen, The Netherlands Abstract--Clay mineralogical studies by X-ray diffraction performed on extracted 2-~m fractions do not always represent all clay mineral constituents present in the soil. In this work, transmission X-ray diffraction (TXRD) was applied to undisturbed microsamples of optically homogeneous mineral soil fabrics and features. These microsamples were isolated by microdrilling their periphery in soil thin sec- tions, then removing them, and transferring them to glass capillaries for TXRD analysis. The usefulness of this technique for supplying in situ mineralogical information on identification, structure, and natural orientation of soil constituents was tested on mineral microfabrics and features of primary and secondary phyllosilicates. The study demonstrated that TXRD allowed detailed, representative interpretations of undisturbed mineral features and fabrics. In particular, this technique allowed us (1) to compare miner-