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Перевод: gneiss

[существительное]
гнейс [геол.]

Тезаурус:

1. The quartzo-feldspathic gneiss contains quartz, feldspar and hornblende as the principal minerals, variable though small amounts of biotite, and with iron ores and apatite as the common accessory minerals present.
2. In general, the gneiss is quartz-rich but variable in character, and with hornblende patches and acid veins occasionally present.
3. Igneous rocks occurring in the Outer Hebrides can be ascribed simply to one of three main groups: a) the igneous complex of South Harris, including the eastern Basic Gneiss of South Uist; b) the granites and pegmatites; and c) the basic dykes.
4. The Archaean bedrock of Lewisian gneiss provides a stable basement platform upon which recent land-forming events such as glaciation, sea level changes and ubiquitous peat-development have been superimposed.
5. The Survey describes the gneisses in this zone as: gneiss with cataclasite fabric meaning gneiss that has suffered crushing; mashed gneiss meaning gneiss that has been severely crushed; and pseudotachylite - close to the actual plane of the thrust, meaning gneiss that has been crushed so severely it is now a black, flinty, very fine grained or glassy rock.
6. The hornblende gneiss is similar in character and mineralogy, but hornblende is invariably the most abundant mineral present.
7. This comprises either quartzo-feldspathic gneiss or hornblende gneiss, often with intercalated amphibolite sheets.
8. The Lewisian gneiss.