greenschist


Also found in: Dictionary, Wikipedia.

greenschist

[′grēn‚shist]
(petrology)
A schistose metamorphic rock with abundant chlorite, epidote, or actinolite present, giving it a green color.
References in periodicals archive ?
The igneous phases are replaced by low temperature, or more rarely medium temperature, metamorphic minerals, developing mineral assemblages typical of the greenschist or amphibolite facies.
The west contact of the dike is faulted and both the dike and the greenschist are intensely altered to clay, resulting in very unstable ground conditions in the tunnel.
Then a second reactivation of deformation and metamorphism under greenschist facies conditions occurred between 47 to 27 Ma.
Titanite is common, especially in clefts in diabase and greenschist.
The occurrence of appreciable amount of epidote and zoisite together with green amphibole and chlorite after clinopyroxene indicates metamorphism of these rocks under greenschist to epidote amphibolite facies conditions.
This is in marked contrast to most anchizone cleavages described in the literature (see Kisch 1991), which are regarded as the precursors to the slaty cleavage that is more fully developed in higher grade anchizonal and greenschist facies pelites.
The upper schist sequence consists of gray, finely banded, phyllite-like quartz-sericite schist with intercalations of apovolcanic greenschist.
9 Ga; Bjork 1986) volcano-sedimentary rocks dominated by felsic, alkali-rich metavolcanics, metabasites, argillitic schists and marbles of greenschist to amphibolite facies grade (e.
These rocks are upper Cambrian to lower Ordovician in age and have been regionally metamorphosed to greenschist facies (Riordon, 1954; St-Julien, 1972; Harron, 1976).

Full browser ?