Quicksand is a shear-thinning suspension or non-Newtonian fluid. More details about quicksand are given here: Quicksand - Wikipedia. read more
These fluids have a linear relationship between viscosity and shear stress. Examples: Water; Mineral oil; Gasoline; Alcohol; NON-NEWTONIAN FLUIDS. You can probably guess that non-Newtonian fluids are the opposite of Newtonian fluids. When shear is applied to non-Newtonian fluids, the viscosity of the fluid changes. read more
Quicksand is a non-Newtonian fluid: when undisturbed, it often appears to be solid (“gel” form), but a minor (less than 1%) change in the stress on the quicksand will cause a sudden decrease in its viscosity (“sol” form). read more