Here's why:
* High Viscosity: Felsic and intermediate magmas are very viscous, meaning they are thick and sticky. This high viscosity prevents the magma from flowing easily, causing it to pile up and form a dome shape.
* Explosive Potential: While not always explosive, these magmas can be prone to explosive eruptions due to the high gas content trapped within the viscous magma.
Examples of common magma types for lava domes:
* Rhyolite: A very felsic magma, often associated with violent eruptions and large, steep-sided domes.
* Andesite: An intermediate magma, often resulting in smaller, less explosive domes.
Important Note: While felsic and intermediate magmas are most common, some basaltic lava domes have been observed, particularly when the magma is particularly viscous due to high gas content or low temperatures.
