Felsicdominated

Felsicdominated is a geological descriptor applied to rocks, magmas, or rock assemblages in which felsic minerals and compositions predominate over mafic ones. In practice, felsic-dominated material contains a large proportion of quartz and feldspars (primarily K-feldspar and plagioclase) and a relatively low proportion of mafic minerals such as pyroxene, olivine, and amphibole. Rocks described as felsic-dominated are typically high in silica and light-colored minerals, and they commonly exhibit high aluminum and low iron-magnesium contents.

Geochemically, felsic-dominated rocks often have silica contents above about 65 wt% and elevated alkalis. They may occur as plutonic bodies such as granite and granodiorite or as volcanic rocks such as rhyolite and dacite. The textures range from coarse-grained, intrusive rocks to finely crystalline or glassy volcanic rocks. The term emphasizes modal and chemical dominance of felsic minerals rather than a strict kinship with a single rock type.

Formation and setting commonly associated with felsic-dominated magmatism include processes in continental crust, such as partial melting of crustal rocks or extensive fractional crystallization of mafic magmas. This style of magmatism is typical of continental arc settings and regions of crustal differentiation, contributing to crustal growth and the development of light-colored intrusive and volcanic suites.

In usage, felsicdominated is descriptive and relative, indicating that felsic minerals and compositions outnumber mafic components within the material being discussed.