A sedimentary rock, composed mostly argillaceous or clay-bearing grains.
A sedimentary rock composed of clay-size particles but lacking the stratified structure that is characteristic of a shale.
A sedimentary rock composed of mineral fragments finer than those in a siltstone.
Mud that has hardened into rock.
a sedimentary rock composed of silt and clay particles, compacted and weakly cemented together by a small quantity of lime.
It is a fine grained sedimentary rocks which are similar to the shales in their non-plasticity, cohesion and low water content but it lack fissility.
a hardened rock composed of clay- and silt-sized grains; not easily split along bedding planes (see shale)
A rock made up of clay and silt sized particles.
1. An indurated mud having the texture and composition of shale, but lacking its fine lamination or fissility; a blocky or massive, fine-grained sedimentary rock in which the proportions of clay and silt are approximately equal; a nonfissile mud shale. See also siltstone. 2. A general term that includes clay, silt, claystone, siltstone, shael, and argillite, and that should be used only when the amounts of clay and silt are not known or specified or cannot be precisely identified. 3. A term used for a mud-supported carbonate sedimentary rock containing less than 10% grains (particles with diameters greater than 20 microns); e.g. a calcilutite. The term specifies neither mineralogic composition nor mud of clastic origin.
A very fine-grained sedimentary rock formed from mud.
Sedimentary rock made of mud particles that have been cemented together over many, many years.
A fine-grained sedimentary rock consisting mainly of clay mineral particles
Fine grained sedimentary rock composed of lithified silt and clay particles.
A sedimentary rock formed from very small particles, mainly of clay minerals. The particles are less than 0.004 mm in diameter.
Mudstone 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 and time the platey clay minerals may become aligned, with the appearance of fissility or parallel layering.
