aphanitic in a sentence
Examples
- Typically, they are less resistant to weathering than the enclosing aphanitic rock and, as a result, form pock-marks on the weathered surfaces of mafic rocks.
- Felsite is a petrologic field term used to refer to very fine-grained or aphanitic, light-colored volcanic rocks which might be later reclassified after a more detailed microscopic or chemical analysis.
- The earlier formed minerals will have formed slowly and remain as large crystals, whereas, sudden cooling causes the rapid crystallization of the remainder of the melt into a fine grained ( aphanitic ) matrix.
- "' Aphanite "', or "'aphanitic "'as an adjective ( from the geological texture results from rapid cooling in volcanic or hypabyssal ( shallow subsurface ) environments.
- The groundmass of these rocks is often aphanitic microcrystalline, with a web of minute feldspars mixed with interstitial grains of quartz or tridymite; but in many dacites it is largely vitreous, while in others it is felsitic or cryptocrystalline.
- "' Phonolite "'is an uncommon extrusive igneous rock, volcanic rock, of intermediate chemical composition between felsic and mafic, with texture ranging from aphanitic ( fine-grain ) to porphyritic ( mixed fine-and coarse-grain ).
- "' Varioles "'are millimeter-to centimeter-scale, light-colored, globular to spherical structures, that are conspicuously observable within aphanitic, mafic igneous rocks, such as basalt, komatiite, and tachylite, that comprise either pillow lavas, subaerial lava flows, or volcanic dykes.