TERMIUM Plus^®

Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 DEF

An igneous rock having a relatively low silica content, sometimes delimited arbitrarily as 44% to 51% or 45% to 52%.  4, record 1, English, - subsilicic%20rock

Record number: 1, Textual support number: 1 CONT

Igneous rocks [are subdivided] into the following groups: silicic or felsic (or acid, an old and discredited but unfortunately entrenched term), rocks having more than 66 percent silica; intermediate, rocks with 55 to 66 percent silica; and subsilicic, rocks containing less than 55 percent silica. The latter may be further divided into two groups: mafic, rocks with 45 to 55 percent ...  5, record 1, English, - subsilicic%20rock

Record number: 1, Textual support number: 1 OBS

"Basic" is one of four subdivisions of a widely used system for classifying igneous rocks based on their silica content: acidic, intermediate, basic, and ultrabasic.  6, record 1, English, - subsilicic%20rock

Record number: 1, Textual support number: 2 OBS

The term "subsilicic rock" is preferred to "basic rock" (the most commonly used term) which is misleading.  7, record 1, English, - subsilicic%20rock

Record number: 1, Textual support number: 3 OBS

"Basic" must not be confused with "alkaline."  7, record 1, English, - subsilicic%20rock

Record 1,  Textual support,  French

Record number: 1, Textual support number: 1 CONT

L'acidité d'une roche est liée à sa teneur en silice, [...] les roches dites basiques en contiennent environ 50 %.  3, record 1, French, - roche%20basique

Record number: 1, Textual support number: 2 CONT

[...] un très grand nombre de dépôts cuprifères, aurifères, cobaltifères, nickélifères, et argentifères se localisent dans des roches basiques [...]  4, record 1, French, - roche%20basique

Record number: 1, Textual support number: 1 OBS

La notion d'acidité, quelque peu ambiguë pour les roches, a été introduite au milieu du siècle dernier par Élie de Beaumont qui, en fonction de la teneur en SiO₂, distingue les roches acides [plus de 65 %], les roches intermédiaires [entre 52 et 65 %], les roches basiques [entre 45 et 52 %] et les roches ultra-basiques [moins de 45 %].  5, record 1, French, - roche%20basique

Record 1,  Textual support,  Spanish

Record number: 1, Textual support number: 1 DEF

Roca que posee menos de un 60% de SiO₂ y en la que no hay sílice libre, sino que toda forma parte de silicatos.  1, record 1, Spanish, - roca%20b%C3%A1sica