An argillaceous rock, differing from shale in being hardened, and from slate in having no slaty cleavage.
fine-grained, metamorphosed mud and claystone. The deep-red-colored argillite artifacts found at the Hardy Site may have come from the Mazatzal Mountains in central Arizona.
a compact rock derived from siltstone, mudstone, or shale which has been hardened or consolidated by pressure, cementation, or heat. It does not break into thin layers, as do shale and slate. It is regarded as a product of weak metamorphism.
A low-grade metamorphic rock made from a shaly sedimentary rock, characterized by irregular fracture and lack of foliation.
a metamorphic rock, intermediate between shale and slate, that does not possess true slaty cleavage
A compact sedimentary rock composed mainly of clay and aluminum silicate materials.
A compact rock, derived from mudstone or shale but more highly indurated than either of those rocks. It lacks the fissility of shale or the cleavage of slate. Argillite is a product of weak metamorphism.
a sedimentary rock differing from shale in being bound by silica and from slate in having no slate cleavages
a rock derived either from siltstone, claystone or shale, that has undergone a somewhat higher degree of induration than is present in those rocks
a sedimentary rock composed of clay particles which have been hardened and cemented.
name used for unusually hard, fine-grained sedimentary rocks, such as shale, mudstone, siltstone, and claystone. Commonly black.
A rock composed mainly of clay-sized particles, which has been lithified (hardened) to a greater degree than shale.
Metamorphic rock resulting from the hardening of siltstone and/or claystone and shale.
A compact rock, derived from mudstone or shale, but more highly indurated and lacks the fissility of shale or the cleavage of slate. It is the product of weak metamorphism.