Physical Science 101
Landforms which develop from eruption of magma and are built of volcanic materials.
Non-violent, effusive eruptions of lava which flows along the surface
Basalt is the most common lava rock type
The type of flow is controlled by the silica composition of the lava
Lava Flow Types
Pahoehoe - very fluid flows - low viscosity; ropy surface appearance; basalt.
Aa - higher viscosity than pahoehoe; surface consists of spiny, angular clinkers; basalt, andesite.
Block flows - surface consists of angular blocks; andesite, rhyolite, obsidian