A deposit of sinter and a calcareous sandstone, known as the Kalahari Kalk, considered by Dr Passarge to be of Miocene age, overlies a sandstone and curious breccia (Botletle Schnichten).
Muffle furnaces are suitable for fine ores which are liable to decrepitate or sinter.
The high temperatures generated fuse the ore particles and fluxes together to form a porous clinker called sinter.
The reduced particles sinter together into a spongy mass which is crushed into a powder.
The sinter process begins with powered glass put into molds and then fired to melt the glass into shapes.
The water of many of the springs contains sulphur, iron, alum and other materials in solution, which in places stain the pure white sinter with bright bands of colour.
The water of most of the springs and geysers holds silica in solution in considerable quantities, so that as it cools and evaporates it deposits a dazzling white sinter which has covered many square miles of the valleys and contrasts strongly with the dark green of the surrounding forests.
There are significant emissions from sinter plants owing more to the large gas volumes emitted than to high concentrations.