What is Felsic Rock?

Felsic is a term used in geology to describe igneous rocks that are rich in silica (SiO2) and have a high aluminum content. These rocks are typically light-colored and have a fine-grained texture. The word "felsic" is derived from the Latin words "fels," meaning "rock," and "siccus," meaning "dry."

Felsic rocks are characterized by their high silica content, which can range from 60% to over 80% SiO2. This high silica content gives felsic rocks their characteristic light color and makes them more resistant to weathering than other types of rocks. Felsic rocks also tend to have a higher aluminum content than mafic rocks, which are rich in magnesium and iron.

Examples of felsic rocks include granite, rhyolite, and tuff. These rocks are often found in areas where there has been significant magmatic activity, such as volcanic regions or mountain-building processes. Felsic rocks can also be formed through the metamorphism of other rocks under high pressure and temperature conditions.