Here's a breakdown:
* Andesitic lava is a type of lava that is intermediate in silica content. It is typically viscous and flows relatively slowly, often forming steep-sided lava flows.
* Basaltic lava, which is lower in silica content, is less viscous and flows more easily.
* Rhyolitic lava, which is higher in silica content, is very viscous and often forms thick, dome-shaped eruptions.
While Mount Shasta's main lava composition is andesitic, it has also produced dacite and even some basaltic lava flows in the past. This is a result of the complex magma chamber beneath the volcano.
It's worth noting that the composition of a volcano's lava can vary over time. This is because the magma beneath the volcano is constantly evolving as it mixes and interacts with surrounding rocks.
