arenaceous Sandy, or sand-like in appearance or texture. The term is applied to clastic sedimentary rocks with a grain size of 0.0625–2.00 mm. Three main groups of arenaceous rocks are recognized: quartz sandstones (quartzites), which contain 95% quartz; arkoses, which have greater than 25% feldspar; and greywackes, which essentially are poorly sorted sediments with rock (lithic) fragments in a mud matrix.

arenaceous Sandy or sand-like in appearance or texture. The term is applied to clastic sedimentary rocks with a grain size 0.0625–2.00 mm. Three main groups of arenaceous rocks are recognized: quartz sandstones (quartzites), which contain 95 per cent quartz; arkoses, which have greater than 25 per cent feldspar; and greywackes, which essentially are poorly sorted sediments with rock (lithic) fragments in a mud matrix. See also arkose.

arenaceous Sandy, or sand-like in appearance or texture. The term is applied to clastic sedimentary rocks with a grain size 0.0625–2.00 mm. Three main groups of arenaceous rocks are recognized: quartz sandstones (quartzites), which contain 95 per cent quartz; arkoses, which have greater than 25 per cent feldspar; and greywackes, which essentially are poorly sorted sediments with rock (lithic) fragments in a mud matrix. See also ARKOSE.

ar·e·na·ceous / ˌarəˈnāshəs/ • adj. Geol. consisting of sand or sandlike particles. ∎  Biol. (of animals or plants) living or growing in sand.