Basse Terre (Guadeloupe, French West Indies), highly weathered porphyric andesitic saprolites that formed under tropical perudic climatic conditions were sam-.
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 M I C R O F A B R I C S 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 S E C T I O N S L. DENAIX, 1 E VAN tORT, 2 M. PERNES,2 AND A.G. JONGMANS3 i Unit6 d'Agronomie INRA, Domaine de la Grande Ferrade, BP 81, 33883 Villenave d'Ornon Cedex, France 2 Unit6 de Science du Sol, INRA, Route de St.-Cyr, 78026 Versailles Cedex, France 3 Department 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 180 150 >100
640
Denaix, van Oort, Pernes, and Jongmans
Clays and Clay Minerals
Vol. 47, No. 5, 1999
TXRD on undisturbed microportions of soil thin sections
641
g 2800 2400 2000
-
.~1600 j 1200 800
~-o
~
400
o
_
0 tO
tO
tt) r
IO e0
t~ '~"
tO tO
tO ID
2 theta (degrees)
Figure 4. TXRD pattern in scanning mode from Morne&-Louis samples, 5-65 ~ range, (a) microsample of groundmass (-7.5 p~g) and (b)
