Lava is the molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. The source of the heat that melts the rock within the earth is geothermal energy.
The following are types of lava and their characteristics
- It is extremely viscous.
- It doesn’t flow very far but it is thrown by the pressure of gases through heat.
- It solidifies rapidly at high temperatures of about 850 degrees Celsius.
- It has low viscosity i.e. very fluid and mobile.
- It is able to flow for very long distances before solidifying.
- It has a silica content of between 45-55% e.g. basalt
- It is fairly viscous and unable to flow far before solidifying.
- Silica content of between 55% to 65%.
- Tranchyte and phonolite.
- It flows very far.
- Silica content of < 45%