FIG. 5. Uranium silicate mineralization in core samples was confined to intragrain microfractures in granitic lithic clasts. (a and b) Backscattered electron images of nm-scale uranyl silicate florettes in fractures; K: potassium feldspar, P: plagioclase feldspar, S: smectite secondary mineralization. (c) Cross-section in transmission electron microscope image of florettes on the fracture face; Pt: platinum coating applied by focused ion beam tool. (d) transmission electron image of microcrystalline uranyl silicate domains within a uranyl silicate.