- quartz-free rocks
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бескварцевые породы
English-Russian dictionary of geology. 2011.
English-Russian dictionary of geology. 2011.
Quartz-porphyry — Quartz porphyry, in petrology, is the name given to a group of hemi crystalline acid rocks containing porphyritic crystals of quartz in a fine grained matrix, usually of micro crystalline or felsitic structure. In specimens, the quartz appears as … Wikipedia
Dynamic quartz recrystallization — Quartzite from Southern Appalachians. Thin section prepared by Michael Stevens. Quartz is the most abundant single mineral in the earth s crust (behind the feldspar group),[1] and as such is present in a very large proportion of rocks both as… … Wikipedia
felsic and mafic rocks — ▪ igneous rock division of igneous rocks (mafic rock) on the basis of their silica content. Chemical analyses of the most abundant components in rocks usually are presented as oxides (oxide) of the elements; igneous rocks typically consist… … Universalium
silica mineral — Any of the forms of silicon dioxide (SiO2), including quartz, tridymite, cristobalite, coesite, stishovite, melanophlogite, lechatelierite, and chalcedony. Various kinds of silica minerals have been produced synthetically. * * * Introduction… … Universalium
rock — rock1 rockless, adj. rocklike, adj. /rok/, n. 1. a large mass of stone forming a hill, cliff, promontory, or the like. 2. Geol. a. mineral matter of variable composition, consolidated or unconsolidated, assembled in masses or considerable… … Universalium
Rock — /rok/, n. a male given name. * * * I In geology, a naturally occurring and coherent aggregate of minerals. The three major classes of rock igneous, sedimentary, and metamorphic are based on the processes that formed them. These three classes are… … Universalium
pyroxene — pyroxenic /puy rok sen ik/, adj. /puy rok seen, peuh , puy rok seen /, n. any of a very common group of minerals of many varieties, silicates of magnesium, iron, calcium, and other elements, occurring as important constituents of many kinds of… … Universalium
quartzite — quartzitic /kwawrt sit ik/, adj. /kwawrt suyt/, n. a granular metamorphic rock consisting essentially of quartz in interlocking grains. [1840 50; QUARTZ + ITE1] * * * Sandstone that has been converted into a solid quartz rock. Quartzites are… … Universalium
Environmental radioactivity — is produced by radioactive materials in the human environment. While some radioisotopes, such as strontium 90 (90Sr) and technetium 99 (99Tc), are only found on Earth as a result of human activity, and some, like potassium 40 (40K), are only… … Wikipedia
perlite — perlitic /perr lit ik/, adj. /perr luyt/, n. Petrog. a volcanic glass in which concentric fractures impart a distinctive structure resembling masses of small spheroids, used as a plant growth medium. Also, pearlite. [1825 35; < F; see PEARL1,… … 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