Soil mechanics not moving, the water pressure obeys the equation of hydrostatic equilibrium, formula_89, but note that formula_93, is negative above the water table. Hence, hydrostatic water pressures are negative above the water table. The thickness of the zone of capillary saturation depends on the pore size, but typically, the heights vary between a centimeter or so for coarse sand to tens of meters for a silt or clay. In fact the pore space of soil is a uniform fractal e.g. a set of uniformly distributed D-dimensional fractals of average linear size L. For the clay soil it has been found that
Quartz arenite Quartz arenite A quartz arenite or quartzarenite is a sandstone composed of greater than 90% detrital quartz, with limited amounts of other framework grains (feldspar, lithic fragments, etc.) and matrix. It can have higher-than-average amounts of resistant grains, like chert and minerals in the ZTR index. The term 'quartz arenite' is derived from the main component (quartz) and arenite, a Latin term for a rock with sand-sized grains. In some literature, these can be called orthoquartzites, a confusing term which usually refers to the metamorphic rock quartzite, though most metamorphic quartzites are diagentically fused from quartz arenites. The term "quartzose