mudstone


 * Mudstone** (also called **[|mudrock]**) is a fine grained [|sedimentary rock] whose original constituents were [|clays] or [|muds]

[|Grain size] is up to 0.0625 mm (0.0025 in) with individual grains too small to be distinguished without a microscope. With increased pressure over time the platey [|clay].

[|mudstone (rock)] sedimentary rock composed primarily of clay- or silt-sized particles (less than 0.063

...(116 millimetre to 1256 millimetre diameters), claystone (less than 1256 millimetre), and mudstone (a mix of silt and clay).

With increased pressure over time the platey clay minerals may become aligned, with the appearance of fissility or parallel layering. This finely bedded material that splits readily into thin layers is called shale, as distinct from mudstone.