Sentence examples for alkalic from inspiring English sources

As noted previously, they are considered here primarily because they are the specific minerals used in naming alkalic igneous rocks.

They are found in alkalic rocks such as nepheline syenites and phonolites, wherein they are associated with orthoclase, feldspathoids, augite, and sodium-rich amphiboles.

They are considered to be the specific minerals of igneous rocks usually termed alkalic, which is the designation applied to igneous rocks whose alkali content (i.e., amount of sodium [Na] and/or potassium [K]) exceeds the amount required by the available silica to form one or more feldspars plus or minus mica.

Nepheline is the most common feldspathoid; it is a major constituent of many alkalic igneous rocks such as nepheline syenites.

To this end he diligently visited classical localities relating to problems of igneous rocks: the Bushveld of South Africa, the alkalic lavas of East Africa, and the peridotites of Skye and the Fen area of Norway.

The long-extinct volcano of Mount Kenya has been much denuded, and the highest peaks consist of the crystalline nepheline-syenite (a granular rock of alkalic feldspar, nepheline, and other minerals), which plugged the former vent.

Basaltic and alkalic igneous magmas therefore can crystallize only minor amounts of silica minerals, and sometimes none are produced.

Columbite is normally found in intrusive pegmatite and biotite and in alkalic granites.

In Japan a tholeiitic series and a calc-alkalic series sometimes erupt from the same volcano.

The calc-alkalic series lacks pigeonite but instead has hypersthene.

Most of the composite volcanoes of the Cascades Range in Oregon and Washington in the northwestern United States are characteristically calc-alkalic.