Here's why:

* Felsic is a term used to describe igneous rocks (and their parent magma) that are rich in feldspar and silica.

* Silica (SiO2) is a key component that increases the viscosity (thickness) of magma.

* Thick magma flows slowly, often forming explosive eruptions due to the buildup of pressure.

Other characteristics of felsic magma:

* High viscosity: Silica forms strong bonds, leading to a thick, sticky consistency.

* Light color: Felsic rocks tend to be light-colored, often appearing white, gray, or pink.

* High gas content: Felsic magma often contains a high amount of dissolved gases, which can contribute to explosive eruptions.

Examples of felsic igneous rocks include granite and rhyolite.