Felsic rocks and magmas are enriched in light elements such as silicon, oxygen, aluminum, sodium, and potassium. They are typically light in color and have lower specific gravity compared to mafic rocks. Common examples include granite and rhyolite, which form from highly viscous, silica-rich magma that often leads to explosive volcanic eruptions or massive intrusive bodies.
Heard on the job
The drill core transitioned from a dark basalt into a highly felsic pegmatite layer.
Insider tip
The word is a portmanteau of feldspar and silica. If a rock is pale, pink, or white, it is usually felsic.