(జియాలజీ,

groundmass's Usage Examples:

igneous rocks which have primary mineralogy consisting of amphibole or biotite, and with feldspar in the groundmass.

Igneous rocks with >90% amphiboles, which have a feldspar groundmass, may be a lamprophyre.

basalts and by the presence of olivine and titanium-rich augite in its groundmass and phenocrysts, and nepheline in its CIPW norm.

usually conspicuous crystal distinctly larger than the grains of the rock groundmass of an igneous rock.

However, in aphanites, or rocks with phenocrysts clearly out of equilibrium with the groundmass.

Porphyroclasts are fragments of the original rock before dynamic recrystallisation or cataclasis produced the groundmass.

felsic type such as felsites and rhyolites, may have a cryptocrystalline groundmass as distinguished from pure obsidian (felsic) or tachylyte (mafic), which.

forms when the groundmass of ultramafic rocks, most commonly mantle peridotites, is partially altered to carbonate minerals and cut by ubiquitous carbonate.

through their fine-grained groundmass.

trachyandesite, composed of olivine, augite and plagioclase phenocrysts in a groundmass with calcic plagioclase and sanidine and some dark-colored volcanic glass.

The groundmass mineralogy, which more closely resembles a true composition of.

Structures that imply tectonic movements are signs of cataclasis: on magmatic plagioclases on groundmass minerals like quartz along the.

A sample of andesite (dark groundmass) with amygdaloidal vesicles filled with zeolite.