Greywacke - Wikipedia Greywackes are mostly grey, brown, yellow, or black, dull-colored sandy rocks that may occur in thick or thin beds along with shales and limestones Some varieties include feldspathic greywacke, rich in feldspar, and lithic greywacke, rich in other tiny rock fragments
Greywacke Rock | Properties, Formation, Uses - Geology Science If the rock has between 10 and 50% clay matrix, the rock is called a wacke Quartz wackes have predominantly quartz surrounded by a mud or clay matrix In a feldspathic wacke, feldspar is more abundant, and in a lithic wacke, lithic fragments are more abundant
Wackestone - Wikipedia Under the Dunham classification (Dunham, 1962 [1]) system of limestones, a wackestone is defined as a mud-supported carbonate rock that contains greater than 10% grains
Sedimentary rock - Wackes, Stratification, Deposition | Britannica Sedimentary rock - Wackes, Stratification, Deposition: Wacke, or graywacke, is the name applied to generally dark-coloured, very strongly bonded sandstones that consist of a heterogeneous mixture of rock fragments, feldspar, and quartz of sand size, together with appreciable amounts of mud matrix
Wacke | Clastic, Sedimentary Igneous | Britannica Wacke, sedimentary rock composed of sand-sized grains (0 063–2 mm [0 0025–0 078 inch]) with a fine-grained clay matrix The sand-sized grains are frequently composed of rock fragments of wide-ranging mineralogies (e g , those consisting of pyroxenes, amphiboles, feldspars, and quartz)
Wacke: Mineral information, data and localities. - mindat. org A dirty sandstone that consists of a mixed variety of angular and unsorted or poorly sorted mineral and rock fragments, and of an abundant matrix of clay and fine silt; specif an impure sandstone containing more than 10% argillaceous matrix The term is used for a major category of sandstone, as distinguished from arenite ii
Greywacke: Mineral information, data and localities. - mindat. org A wacke generally consisting of poorly sorted angular grains of quartz, feldspar and lithic fragments set in a compact clay-rich matrix It is commonly formed from sediment deposited in submarine avalanches or from strong turbidity currents creating mixed-sediment slurries
6. 1: Clastic Sedimentary Rocks - Geosciences LibreTexts Sandstones with more than 15% silt and clay are called wackes (e g , quartz wacke, lithic wacke) It’s worth taking a closer look at the different types of sandstone because sandstone is a common and important sedimentary rock
Graywacke Sandstone FAQ - U. S. National Park Service Graywacke sandstone is a sedimentary rock that is made up mostly of sand-size grains that were rapidly deposited very near the source rock from which they were weathered