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

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.