Journal of the Royal Society of Western Australia, 87(4), December 2004 
Figure 4. Sediments and sedimentary features from various wetlands. A. Desiccation of calcilutite forming mud crack polygons at the 
surface or the wetland margin during a dry phase in the hydrological cycle. B. Desiccation of diatomite forming mud crack polygons at 
the surface of the wetland margin during a dry phase In the hydrological cycle. Some examples of diatom mud-coated vegetation 
t e ris (wigs) are arrovyed. C. Development of intraclast gravel of diatomite along a wetland margin by break-up of desiccated 
latomite; older bleached diatomite intraclasts are arrowed. D. Surface layer of sediment showing several cycles of diatomite intraclasts 
(medium grey to bleached) incorporated into the sediment. E. Small thin lens of intraclast gravel of diatomite (arrowed) concentrated 
by wave action during high water. F. Concentration of diatomite intraclast gravel in a polygonal desiccation crack (outlined). G. 
Duitonute mtraclasts (arrow 3) incorporated into the white sand apron (arrow 2) along the edge of a wetland; in this example, the thin 
sand deposit rests on grey diatomite (arrow 1). H. Thin veneers of white sand (arrow 2) transported into the margin of a wetland by 
sheet wash, forming an apron, in this example resting on dark grey diatomite (arrow 1). 
150 
