A combination of ESEM, EDX and XRD studies on the fabric of Dutch organic clay from Oostvaardersplassen (Netherlands) and its geotechnical implications

Fabric study, using an environmental scanning electron microscope (ESEM) with a specially designed cooling stage, combined with energy diffraction analysis of X-rays (EDX), has been carried out on organic and calciferous clay from Oostvaardersplassen in the Netherlands for geotechnical engineering research purposes. Three types of clay states have been used: natural, remolded and fractured. ESEM and EDX test results reveal that this clay consists mostly of organic colloid/tissue clothed silt, microfossils, biological remains. Clay minerals were found to be a small fraction. Attention was then drawn to the identification of micro-morphology of calciferous and organic matter present in this clay, by combining these different techniques: ESEM, EDX and optical microscopy. Results indicate the presence of colloid-like film pieces of organic matter throughout the clay which implies the geotechnical properties of this clay, such as strength, could be increased because of cementation.