Transmission x-ray diffraction of undisturbed soil microfabrics obtained by microdrilling in thin sections

L. Denaix, F. van Oort, M. Pernes, A.G. Jongmans

Research output: Contribution to journalArticleAcademicpeer-review

8 Citations (Scopus)

Abstract

Clay mineralogical studies by X-ray diffraction performed on extracted <2-μm 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 sections, 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 mineralogical compositions at selected microlocalities, (2) to study natural preferred orientations, and (3) to detect small amounts of minor mineral interstratification phases. In addition, complementary information on crystallography and crystal chemistry may be obtained by performing analytical transmission electron microscopy on the same microsample. | Clay mineralogical studies by X-ray diffraction performed on extracted <2-μm 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 sections, 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 compared mineralogical compositions at selected microlocalities, (2) to study natural preferred orientations, and (3) to detect small amounts of minor mineral interstratification phases. In addition, complementary information on crystallography and crystal chemistry may be obtained by performing analytical transmission electron microscopy on the same microsample.
Original languageEnglish
Pages (from-to)637-646
JournalClays and Clay Minerals
Volume47
Issue number5
DOIs
Publication statusPublished - 1999

Keywords

  • soil micromorphology
  • clay minerals
  • x radiation
  • soil analysis

Fingerprint Dive into the research topics of 'Transmission x-ray diffraction of undisturbed soil microfabrics obtained by microdrilling in thin sections'. Together they form a unique fingerprint.

Cite this