- graywackes
- n. (Geology) coarse-grained wacke of dark gray color
English contemporary dictionary. 2014.
graywackes
Look at other dictionaries:
Dalradian Series — ▪ geology sequence of highly folded and metamorphosed sedimentary and volcanic rocks of late Precambrian to Early Cambrian age, about 540 million years old, that occurs in the southeastern portions of the Scottish Highlands of Great Britain … Universalium
Masaya Volcano — View of the crater Elevation 635 m (2,083 ft) … Wikipedia
Geosyncline — In geology, geosyncline is a term still occasionally used for a subsiding linear trough that was caused by the accumulation of sedimentary rock strata deposited in a basin and subsequently compressed, deformed, and uplifted into a mountain range … Wikipedia
Ouachita orogeny — The Ouachita Mountains lie south of the Arkansas River valley which separates them from the Ozark plateau. The Ouachita orogeny was a mountain building event that resulted in the folding and faulting of strata currently exposed in the Ouachita… … Wikipedia
geosyncline — /jee oh sin kluyn/, n. Geol. a portion of the earth s crust subjected to downward warping during a large span of geologic time; a geosynclinal fold. [1890 95; GEO + SYNCLINE] * * * I Linear trough of subsidence of the Earth s crust, in which vast … Universalium
Precambrian time — Interval of geologic time from с 3. 8 billion years ago, the age of the oldest known rocks, to 544 million years ago, the beginning of the Cambrian Period. This interval represents more than 80% of the geologic record and thus provides important… … Universalium
Triassic Period — Interval of geologic time, с 248–206 million years ago, that marks the beginning of the Mesozoic Era. Many new vertebrates emerged during the Triassic, heralding the major changes that were to occur in both terrestrial and marine life forms… … Universalium
metamorphic rock — Any of a class of rocks that result from the alteration of preexisting rocks in response to changing geological conditions, including variations in temperature, pressure, and mechanical stress. The preexisting rocks may be igneous, sedimentary,… … Universalium
sedimentary rock — Rock formed at or near the Earth s surface by the accumulation and lithification of fragments of preexisting rocks or by precipitation from solution at normal surface temperatures. Sedimentary rocks can be formed only where sediments are… … Universalium
