* Basaltic magma is very fluid: It has a low viscosity, meaning it flows easily. This fluidity allows it to spread out over large areas through fissures, creating vast lava flows.
* Low silica content: Basaltic magma has a relatively low silica content, which contributes to its fluidity.
* High temperatures: Basaltic magma is generally hotter than other types of magma, further contributing to its low viscosity.
While basaltic magma is the most common type associated with fissure eruptions, other types of magma can also erupt through fissures, albeit less frequently. These include:
* Andesitic magma: This type of magma, with intermediate silica content, can sometimes erupt through fissures, but usually in smaller volumes compared to basaltic eruptions.
* Rhyolitic magma: This highly viscous magma with high silica content is rarely associated with fissure eruptions. Its high viscosity makes it difficult to flow through fissures.
Key takeaway: Fissure eruptions are primarily characterized by the outpouring of large volumes of fluid, basaltic lava, creating vast lava plains and shield volcanoes.
