There are three main types of lava: a'a, pahoehoe and pillow lava. Each one flows at a different rate and has a different mineral composition.
A'a is the slowest flowing type of lava. Its flow is characterized by its rough outer surface that, once hardened, turns into a sharp, spiny surface that makes travel difficult. The second kind of lava is pahoehoe; it is the fastest flowing lava. These thin lava flows can stretch for miles and form a crust that is very smooth. The last kind of lava is pillow lava, which is normally found underwater. As it erupts and cools due to the water, cracks form and lava oozes out, producing a crust that resembles a pillow.Learn More
Basic lava, also called mafic lava, is a type of lava that consists of 50 percent silica. This type of lava is highly fluid and commonly creates large lava flows. Basic lava can reach speeds of up to 20 miles per hour and reach distances of 60 miles.Full Answer >
Stacks of lava that are very thick can take years to cool down completely. Lava forms a thin crust at the top that cools in 10 to 15 minutes, but the flow underneath can take much longer to cool.Full Answer >
According to the American Geophysical Union, lava forms in the Earth's mantle and flows to the surface through volcanoes. Internal gas pressure within the volcano causes it to spew lava with the amount of pressure depending on how much and how quickly.Full Answer >
Mafic and felsic lava are two types of lava that differ in the amount of silica present in the lava. Felsic lava has a high silica content, while mafic lava is low in silica. Silica forms chains in cooling lava, making it more viscous. This makes mafic lava able to travel longer distances than felsic lava before it cools.Full Answer >