Fabric of Leda clay investigated by optical, electron-optical, and X-ray diffraction methods

Abstract

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur.Engineering Geology, 4, 2, pp. 133-153, 1970-07-01 Fabric of leda clay investigated by optical, electron-optical, and x-ray diffraction methods Gillott, J. E. Fabric, palaeosalinity and engineering data are given for five samples of Leda clay. It is shown that the layer structure silicates in two of the samples are oriented parallel to the bedding; that in the other three samples the platy minerals have a near random arrangement. X-ray diffraction studies showed that there was no difference in the orientation of 7A and 10A layer structure silicates.Palaeosalinity values deduced from boron content indicate that three of the samples were deposited in water that was fresher than normal marine. The other two samples were deposited in a nearly normal marine environment. The correlation between fabric and palaeosalinity data is fairly good, though information on a larger number of samples is needed before the method can be satisfactorily evaluated for Leda clay.Moisture removal by four different methods shows that original fabric can be affected by the technique of sample preparation.The evidence is in agreement with the idea that fabric was Inore affected by conditions at the time of deposition than by subsequent events.

Review of engineering behaviour of marine clays in Eastern Canada

“…Penner ( 1963) also had studied preferred orientation in Leda clay, both by photographing the change in light 1 reinforcement and interference during rotation of thin sections between crossed polaroids, and by anisotropic thermal conduction. Both methods gave the same results and were supported by Gillott's ( 1970) work. The open type of fabric was formed during sedimentation in saline water of various levels of electrolyte concentration, i.e.…”

“…The mineralogical composition of the marine clays may be summarized as follows (Brydon and Patry 1961 ;Gillott 1970) : Montmorillonite or other expanding layer silicates are absent, or present only in small quantities. Some chlorites anc!…”

“…2. Scanning electron micrographs of Leda clay from the Ottawa Sewage Plant from a depth of 16.2 m and a preconsolidation load of 478 kPa (from Gillott (1970), reproduced with permission from Engineering Geology).…”

“…The ' I scanning electron micrograph of the sample shows I some particle orientation parallel to the bedding plane. The degree of orientation was considerable, I based on X-ray diffractograms using both chlorite i and illite minerals (Gillott 1970). Penner ( 1963) also had studied preferred orientation in Leda clay, both by photographing the change in light 1 reinforcement and interference during rotation of thin sections between crossed polaroids, and by anisotropic thermal conduction.…”

Microstructure Investigation in Unsaturated Soils: A Review with Special Attention to Contribution of Mercury Intrusion Porosimetry and Environmental Scanning Electron Microscopy

“…It is a difficult task to make a representative selection of the techniques, their use and interpretation, since it is an experimental subject of interest for geologists, soil scientists and geotechnical engineers. In fact, much of the previous work on the microstructure of fine-grained soils was initiated by soil scientists and developed by engineering geologists within the framework of highly sensitive post-glacial clays and soft soils (Gillott 1970(Gillott , 1979Pusch 1970;Delage and Lefebvre 1984;Bennet et al 1991). The reader may observe that despite the representative selection of contributions there will be some tendency towards the works performed by the respective research groups of the authors.…”