Definition of mudstone in English:



  • A dark sedimentary rock formed from consolidated mud and lacking the laminations of shale.

    ‘The sedimentary lenses are composed of limestone, sandstone, siltstone, mudstone, shale, chert and well-bedded calci-turbidite.’
    • ‘The matrix varies in composition from black shale to carbonate mudstone and quartzose siltstone.’
    • ‘The upper contacts are mostly sharp and overlain by interbedded mudstone, dark brown mudstone, laminated mudstone and occasionally fine-grained sandstone.’
    • ‘Gibling interpreted the assemblage of mudstone, coal and oil shale in the Cenozoic basins of Thailand as the product of deposition in environments where lake levels fluctuated.’
    • ‘We scrambled up the mountain and worked all day on the snow-covered slopes exploring the wide, flat terraces of dark shale and reddish-brown mudstone.’
    • ‘The Caister Coal Formation contains a significant proportion of sandstone, with mudstone and coal arranged in cyclical units.’
    • ‘The Brushy Basin shales, mudstones, and sandstones were deposited by a series of rivers and streams originating from the west and containing large volumes of volcanic ash.’
    • ‘The sequences are characterized by thin laminated marlstones, calcareous mudstones, claystones, shales and some thin coal beds.’
    • ‘Between Staithes to the north of Whitby and Ravenscar to the south, the rock that makes up the coast is soft shale and mudstone laid down during the lower Jurassic, about 200 million years ago.’
    • ‘North of the Burd Gol zone there is a small area of interbedded marine mudstone and limestone which reportedly contain Carboniferous fossils.’
    • ‘The rock was mostly poor quality shale and mudstone leaving a smooth soapy floor underfoot and this continued for a few hundred metres without respite.’
    • ‘The unit comprises a thinly laminated heterolith of mudstone and fine-grained sandstone.’
    • ‘The fossils are found in siltstone and mudstone under limestone.’
    • ‘Relatively impermeable sedimentary rocks, such as mudstones and clay-cemented sandstones, are particularly susceptible to such rapid erosion and most badlands develop on such materials.’
    • ‘The Elgee Siltstone consists of massive red siltstone, sandstone and green mudstone.’
    • ‘As the name implies siltstone is composed mostly of silt particles and contains less clay and shale and mudstone.’
    • ‘This facies consists of distinctly laminated mudstone, with a minor component of siltstone and very fine-grained sandstone.’
    • ‘Occasional thin dark grey laminated mudstones are associated with some of the sandstones.’
    • ‘Where found alternating with massive mudstone and thin coal seams, these sands probably formed as sheet-like floodplain deposits.’
    • ‘In contrast, valleys generally develop in areas dominated by shales and mudstones.’



/ˈmədˌstōn/ /ˈmədˌstoʊn/