- alkali rock
- Mineral.any igneous rock with a marked preponderance of alkali and a low percentage of silica.
Useful english dictionary. 2012.
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alkali rock — Mineral. any igneous rock with a marked preponderance of alkali and a low percentage of silica. * * * … Universalium
Rock microstructure — includes the texture of a rock and the small scale rock structures. The words texture and microstructure are interchangeable, with the latter preferred in modern geological literature. However, texture is still acceptable because it is a useful… … Wikipedia
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
igneous rock — Any of various crystalline or glassy, noncrystalline rocks formed by the cooling and solidification of molten earth material (magma). Igneous rocks comprise one of the three principal classes of rocks, the others being metamorphic and sedimentary … Universalium
Moon rock — Olivine basalt collected by Apollo 15. Moon rock describes rock that formed on the Earth s moon. The term is also loosely applied to other lunar materials collected during the course of human exploration of the Moon. The rocks collect … Wikipedia
Igneous rock — Geologic provinces of the world (USGS) Shield … Wikipedia
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
Some typical occurrences of the rock-forming feldspars — ▪ Table Some typical occurrences of the rock forming feldspars Potassium feldspars* sanidine potassium rich volcanic rocks and near surface minor intrusions e.g., rhyolites, trachytes, and high temperature contact metamorphic rocks orthoclase… … Universalium
Common rock-forming minerals — ▪ Table Common rock forming minerals quartz calcite biotite hematite alkali feldspars dolomite muscovite limonite plagioclase feldspars clay minerals amphibole … Universalium
Black Rock Desert — ▪ region, Nevada, United States arid region of lava beds and alkali flats composing part of the Basin and Range Province and lying in Humboldt and Pershing counties of northwestern Nevada, U.S. With an area of about 1,000 square miles… … Universalium