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Mapping of the orientation of fine-grained minerals in soils and sediments

  • N. K. Tovey
  • D. H. Krinsley
Article

Abstract

A technique is described which enables the orientation of fine-grained minerals, which frequently surround larger mineral grains in soils and sediments, to be mapped as regions or domains containing similarly aligned features. Several stages are required, beginning with the digital acquisition of back-scattered electron images and associated elemental maps. Mineral classification provides a means to create an image mask to remove the larger grains before analysis of the fine-grained fraction. Orientation analysis by the intensity gradient method is followed by domain segmentation. Finally, this domain segmented image is combined with the original to highlight both orientation and fine detail. Such a resulting image provides a more objective way of interpreting clay coating features, and enables the size and general orientation of the domains to be assessed.

Keywords

Pyrite Intensity Gradient Binary Mask Orientation Analysis Large Mineral 

Cartographie de l'Orientation des Particules Minérales de Petites Dimensions dans les sols et les Sédiments

Résumé

L'article décrit une technique qui permet de cartographier, sours forme de secteurs ou domaines présentant des caractéristiques d'orientation similaires, les minéraux de petites dimensions qui entourent fréquemment les grains plus grossiers. Plusieurs étapes sont nécessaires, commençant par l'acquisition d'images d'électrons rétrodiffusés et des cartes d'éléments qui leur sont associées. Le classement des minéraux donne les moyens de créer un masque qui enléve les grains plus grossiers avant l'analyse de la fraction fine. L'analyse de l'orientation par la méthode du gradient d'intensité est suive d'un découpage par domaines. Finalement cette image découpée en domaines est combinée avec l'image originale pour faire ressortir à la fois l'orientation et les détails très fins. Une telle image résultante fournit un moyen d'interprétation plus objectif des caractéristiques des enrobages argileux, et permet de mettre en évidence la dimension et l'orientation générale des différents domaines.

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Copyright information

© International Assocaition of Engineering Geology 1992

Authors and Affiliations

  • N. K. Tovey
    • 1
  • D. H. Krinsley
    • 2
  1. 1.School of Environmental SciencesUniversity of East AngliaNorwich
  2. 2.Department of GeologyArizona State UniversityTempeUSA

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