teschenite An undersaturated, medium-to coarse-grained, igneous rock consisting of essential calcium-plagioclase, analcime, titanaugite, and barkevikite, with accessory iron oxide. The rock is similar to essexite but with analcime taking the place of nepheline. The teschenite of the Lugar sill, in Ayrshire, Scotland, is a well-known British example.
More From encyclopedia.com
Magnetite , magnetite (loadstone, lodestone) An important rock-forming iron oxide Fe2+Fe3+2O4 (FeO.Fe2O3) and member of the spinel group of minerals; belongs to… Country Rock , Country rock The term country rock refers to a body of rock that receives or hosts an intrusion of a viscous geologic material. Intrusions into count… Basic Rock , basic rock Rock with a relatively high concentration of iron, magnesium, and calcium, and with 45–53% of silica by weight. Examples include gabbro, w… Monocline , Monocline Monoclines are folds consisting of two horizontal (or nearly so) limbs connected by a shorter inclined limb. They can be compared to anticl… xenolith , xenolith An inclusion or enclave of a preexisting rock in an igneous rock. Xenoliths are often derived from the country rocks that have been invaded… Aphanitic , Aphanitic Crystalline rocks with mineral grains that cannot be distinguished from one another without magnification have an aphanitic igneous texture…
About this article
Updated About encyclopedia.com content Print Article
You Might Also Like